Sample records for wafer scale liga

  1. A Batch Wafer Scale LIGA Assembly and Packaging Technique vai Diffusion Bonding

    Energy Technology Data Exchange (ETDEWEB)

    Christenson, T.R.; Schmale, D.T.


    A technique using diffusion bonding (or solid-state welding) has been used to achieve batch fabrication of two- level nickel LIGA structures. Interlayer alignment accuracy of less than 1 micron is achieved using press-fit gauge pins. A mini-scale torsion tester was built to measure the diffusion bond strength of LIGA formed specimens that has shown successful bonding at temperatures of 450"C at 7 ksi pressure with bond strength greater than 100 Mpa. Extensions to this basic process to allow for additional layers and thereby more complex assemblies as well as commensurate packaging are discussed.

  2. Through-Wafer Optical Interconnects For Multi-Wafer Wafer-Scale Integrated Architectures (United States)

    Hornak, L. A.; Tewksbury, S. K.; Hatamian, M.; Ligtenberg, A.; Sugla, B.; Franzon, P.


    Hybrid mounting of optical components, combined perhaps with integrated optical waveguides and lenses on a large area silicon, wafer-scale integrated (WSI) electronic circuit provides one potential approach to combine advanced electronic and photonic functions. The desire to achieve a high degree of parallelism in multi-wafer WSI-based architectures has stimulated study of three-dimensional interconnect structures obtained by stacking wafer circuit boards and. providing interconnections vertically between wafers over the entire wafer area in addition to planar connections. While presently it is difficult for optical interconnects to compete with electrical interconnects in the wafer plane, it is appropriate to look at vertical optical interconnections between wafer planes since the corresponding conductive structures would be large in area and may impede system repairability. The ability to pass information optically between circuit planes without mechanical electrical contacts offers potential advantages for multi-wafer WSI or other dense three-dimensional architectures. However, while optical waveguides are readily fabricated in the plane of the wafer, waveguiding vertically through the wafer is difficult. If additional processing is required for waveguides or lenses, it should be compatible with standard VLSI processing. This paper presents one straightforward method of meeting this criterion. Using optical device technology operating at wavelengths beyond the ≍1.1μm Si absorption cutoff, low loss, through-wafer propagation between WSI circuit boards can be achieved over the distances of interest (≍1mm) with the interstitial Si wafers as part of the interconnect "free-space" transmission medium. The thickness of existing VLSI layers can be readily adjusted in featureless regions of the wafer to provide antireflection windows such that the transmittance can be raised to ≍77% for n-type and to ≍97% for p-type silicon. Optical interconnect source

  3. Wafer scale oblique angle plasma etching

    Energy Technology Data Exchange (ETDEWEB)

    Burckel, David Bruce; Jarecki, Jr., Robert L.; Finnegan, Patrick Sean


    Wafer scale oblique angle etching of a semiconductor substrate is performed in a conventional plasma etch chamber by using a fixture that supports a multiple number of separate Faraday cages. Each cage is formed to include an angled grid surface and is positioned such that it will be positioned over a separate one of the die locations on the wafer surface when the fixture is placed over the wafer. The presence of the Faraday cages influences the local electric field surrounding each wafer die, re-shaping the local field to be disposed in alignment with the angled grid surface. The re-shaped plasma causes the reactive ions to follow a linear trajectory through the plasma sheath and angled grid surface, ultimately impinging the wafer surface at an angle. The selected geometry of the Faraday cage angled grid surface thus determines the angle at with the reactive ions will impinge the wafer.

  4. Wafer integrated micro-scale concentrating photovoltaics (United States)

    Gu, Tian; Li, Duanhui; Li, Lan; Jared, Bradley; Keeler, Gordon; Miller, Bill; Sweatt, William; Paap, Scott; Saavedra, Michael; Das, Ujjwal; Hegedus, Steve; Tauke-Pedretti, Anna; Hu, Juejun


    Recent development of a novel micro-scale PV/CPV technology is presented. The Wafer Integrated Micro-scale PV approach (WPV) seamlessly integrates multijunction micro-cells with a multi-functional silicon platform that provides optical micro-concentration, hybrid photovoltaic, and mechanical micro-assembly. The wafer-embedded micro-concentrating elements is shown to considerably improve the concentration-acceptance-angle product, potentially leading to dramatically reduced module materials and fabrication costs, sufficient angular tolerance for low-cost trackers, and an ultra-compact optical architecture, which makes the WPV module compatible with commercial flat panel infrastructures. The PV/CPV hybrid architecture further allows the collection of both direct and diffuse sunlight, thus extending the geographic and market domains for cost-effective PV system deployment. The WPV approach can potentially benefits from both the high performance of multijunction cells and the low cost of flat plate Si PV systems.

  5. Wafer-scale micro-optics fabrication (United States)

    Voelkel, Reinhard


    Micro-optics is an indispensable key enabling technology for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly-efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the past decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks, bringing high-speed internet to our homes. Even our modern smart phones contain a variety of micro-optical elements. For example, LED flash light shaping elements, the secondary camera, ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by the semiconductor industry. Thousands of components are fabricated in parallel on a wafer. This review paper recapitulates major steps and inventions in wafer-scale micro-optics technology. The state-of-the-art of fabrication, testing and packaging technology is summarized.

  6. Wafer-scale charge isolation technique

    Energy Technology Data Exchange (ETDEWEB)

    Colella, N.J.; Kimbrough, J.R.


    An apparatus and method are described which improve the performance of charge-coupled devices (CCD) in the presence of ionizing radiation. The invention is a wafer scale charge isolation technique which inhibits or reduces the flow of electrons created by the passage of ionizing radiation in the bulk regions of a silicon CCD. The technique has been tested in a device designed for operating in the infra-red wavelength band. The technique prevents charge from reaching the active charge collection volume of a pixel in a CCD.

  7. Wafer-scale pixelated detector system

    Energy Technology Data Exchange (ETDEWEB)

    Fahim, Farah; Deptuch, Grzegorz; Zimmerman, Tom


    A large area, gapless, detection system comprises at least one sensor; an interposer operably connected to the at least one sensor; and at least one application specific integrated circuit operably connected to the sensor via the interposer wherein the detection system provides high dynamic range while maintaining small pixel area and low power dissipation. Thereby the invention provides methods and systems for a wafer-scale gapless and seamless detector systems with small pixels, which have both high dynamic range and low power dissipation.

  8. Wafer-scale Mitochondrial Membrane Potential Assays (United States)

    Lim, Tae-Sun; Davila, Antonio; Zand, Katayoun; Douglas, Wallace C.; Burke, Peter J.


    It has been reported that mitochondrial metabolic and biophysical parameters are associated with degenerative diseases and the aging process. To evaluate these biochemical parameters, current technology requires several hundred milligrams of isolated mitochondria for functional assays. Here, we demonstrate manufacturable wafer-scale mitochondrial functional assay lab-on-a-chip devices, which require mitochondrial protein quantities three orders of magnitude less than current assays, integrated onto 4” standard silicon wafer with new fabrication processes and materials. Membrane potential changes of isolated mitochondria from various well-established cell lines such as human HeLa cell line (Heb7A), human osteosarcoma cell line (143b) and mouse skeletal muscle tissue were investigated and compared. This second generation integrated lab-on-a-chip system developed here shows enhanced structural durability and reproducibility while increasing the sensitivity to changes in mitochondrial membrane potential by an order of magnitude as compared to first generation technologies. We envision this system to be a great candidate to substitute current mitochondrial assay systems. PMID:22627274

  9. Wafer scale integration of catalyst dots into nonplanar microsystems

    DEFF Research Database (Denmark)

    Gjerde, Kjetil; Kjelstrup-Hansen, Jakob; Gammelgaard, Lauge


    In order to successfully integrate bottom-up fabricated nanostructures such as carbon nanotubes or silicon, germanium, or III-V nanowires into microelectromechanical systems on a wafer scale, reliable ways of integrating catalyst dots are needed. Here, four methods for integrating sub-100-nm...... diameter nickel catalyst dots on a wafer scale are presented and compared. Three of the methods are based on a p-Si layer utilized as an in situ mask, an encapsulating layer, and a sacrificial window mask, respectively. All methods enable precise positioning of nickel catalyst dots at the end...

  10. Wafer-scale nanostructure formation inside vertical nano-pores

    NARCIS (Netherlands)

    Berenschot, Johan W.; Sun, Xingwu; Le The, Hai; Tiggelaar, Roald M.; de Boer, Meint J.; Eijkel, Jan C.T.; Gardeniers, Johannes G.E.; Tas, Niels Roelof; Sarajlic, Edin

    We propose a wafer-scale technique for nanostructure formation inside vertically oriented, through-membrane nano-pores. It uses 50 nm monocrystalline silicon pillars as a mold, embedded in a silicon nitride membrane formed in an innovative step. The proposed technique paves the way towards advanced

  11. Wafer scale coating of polymer cantilever fabricated by nanoimprint lithography

    DEFF Research Database (Denmark)

    Greve, Anders; Dohn, Søren; Keller, Stephan Urs


    Microcantilevers can be fabricated in TOPAS by nanoimprint lithography, with the dimensions of 500 ¿m length 4.5 ¿m thickness and 100 ¿m width. By using a plasma polymerization technique it is possible to selectively functionalize individually cantilevers with a polymer coating, on wafer scale...

  12. Toward wafer scale fabrication of graphene based spin valve devices. (United States)

    Avsar, Ahmet; Yang, Tsung-Yeh; Bae, Sukang; Balakrishnan, Jayakumar; Volmer, Frank; Jaiswal, Manu; Yi, Zheng; Ali, Syed Rizwan; Güntherodt, Gernot; Hong, Byung Hee; Beschoten, Bernd; Özyilmaz, Barbaros


    We demonstrate injection, transport, and detection of spins in spin valve arrays patterned in both copper based chemical vapor deposition (Cu-CVD) synthesized wafer scale single layer and bilayer graphene. We observe spin relaxation times comparable to those reported for exfoliated graphene samples demonstrating that chemical vapor deposition specific structural differences such as nanoripples do not limit spin transport in the present samples. Our observations make Cu-CVD graphene a promising material of choice for large scale spintronic applications.

  13. Wafer-scale plasmonic and photonic crystal sensors (United States)

    George, M. C.; Liu, J.-N.; Farhang, A.; Williamson, B.; Black, M.; Wangensteen, T.; Fraser, J.; Petrova, R.; Cunningham, B. T.


    200 mm diameter wafer-scale fabrication, metrology, and optical modeling results are reviewed for surface plasmon resonance (SPR) sensors based on 2-D metallic nano-dome and nano-hole arrays (NHA's) as well as 1-D photonic crystal sensors based on a leaky-waveguide mode resonance effect, with potential applications in label free sensing, surface enhanced Raman spectroscopy (SERS), and surface-enhanced fluorescence spectroscopy (SEFS). Potential markets include micro-arrays for medical diagnostics, forensic testing, environmental monitoring, and food safety. 1-D and 2-D nanostructures were fabricated on glass, fused silica, and silicon wafers using optical lithography and semiconductor processing techniques. Wafer-scale optical metrology results are compared to FDTD modeling and presented along with application-based performance results, including label-free plasmonic and photonic crystal sensing of both surface binding kinetics and bulk refractive index changes. In addition, SEFS and SERS results are presented for 1-D photonic crystal and 2-D metallic nano-array structures. Normal incidence transmittance results for a 550 nm pitch NHA showed good bulk refractive index sensitivity, however an intensity-based design with 665 nm pitch was chosen for use as a compact, label-free sensor at both 650 and 632.8 nm wavelengths. The optimized NHA sensor gives an SPR shift of about 480 nm per refractive index unit when detecting a series of 0-40% glucose solutions, but according to modeling shows about 10 times greater surface sensitivity when operating at 532 nm. Narrow-band photonic crystal resonance sensors showed quality factors over 200, with reasonable wafer-uniformity in terms of both resonance position and peak height.

  14. Silicon Wafer-Scale Substrate for Microshutters and Detector Arrays (United States)

    Jhabvala, Murzy; Franz, David E.; Ewin, Audrey J.; Jhabvala, Christine; Babu, Sachi; Snodgrass, Stephen; Costen, Nicholas; Zincke, Christian


    The silicon substrate carrier was created so that a large-area array (in this case 62,000+ elements of a microshutter array) and a variety of discrete passive and active devices could be mounted on a single board, similar to a printed circuit board. However, the density and number of interconnects far exceeds the capabilities of printed circuit board technology. To overcome this hurdle, a method was developed to fabricate this carrier out of silicon and implement silicon integrated circuit (IC) technology. This method achieves a large number of high-density metal interconnects; a 100-percent yield over a 6-in. (approximately equal to 15-cm) diameter wafer (one unit per wafer); a rigid, thermally compatible structure (all components and operating conditions) to cryogenic temperatures; re-workability and component replaceability, if required; and the ability to precisely cut large-area holes through the substrate. A method that would employ indium bump technology along with wafer-scale integration onto a silicon carrier was also developed. By establishing a silicon-based version of a printed circuit board, the objectives could be met with one solution. The silicon substrate would be 2 mm thick to survive the environmental loads of a launch. More than 2,300 metal traces and over 1,500 individual wire bonds are required. To mate the microshutter array to the silicon substrate, more than 10,000 indium bumps are required. A window was cut in the substrate to allow the light signal to pass through the substrate and reach the microshutter array. The substrate was also the receptacle for multiple unpackaged IC die wire-bonded directly to the substrate (thus conserving space over conventionally packaged die). Unique features of this technology include the implementation of a 2-mmthick silicon wafer to withstand extreme mechanical loads (from a rocket launch); integrated polysilicon resistor heaters directly on the substrate; the precise formation of an open aperture

  15. Liga developer apparatus system (United States)

    Boehme, Dale R.; Bankert, Michelle A.; Christenson, Todd R.


    A system to fabricate precise, high aspect ratio polymeric molds by photolithograpic process is described. The molds for producing micro-scale parts from engineering materials by the LIGA process. The invention is a developer system for developing a PMMA photoresist having exposed patterns comprising features having both very small sizes, and very high aspect ratios. The developer system of the present invention comprises a developer tank, an intermediate rinse tank and a final rinse tank, each tank having a source of high frequency sonic agitation, temperature control, and continuous filtration. It has been found that by moving a patterned wafer, through a specific sequence of developer/rinse solutions, where an intermediate rinse solution completes development of those portions of the exposed resist left undeveloped after the development solution, by agitating the solutions with a source of high frequency sonic vibration, and by adjusting and closely controlling the temperatures and continuously filtering and recirculating these solutions, it is possible to maintain the kinetic dissolution of the exposed PMMA polymer as the rate limiting step.

  16. Fabrication of CVD graphene-based devices via laser ablation for wafer-scale characterization

    DEFF Research Database (Denmark)

    Mackenzie, David; Buron, Jonas Christian Due; Whelan, Patrick Rebsdorf


    Selective laser ablation of a wafer-scale graphene film is shown to provide flexible, high speed (1 wafer/hour) device fabrication while avoiding the degradation of electrical properties associated with traditional lithographic methods. Picosecond laser pulses with single pulse peak fluences of 1...

  17. Tailoring the graphene/silicon carbide interface for monolithic wafer-scale electronics

    National Research Council Canada - National Science Library

    Hertel, S; Waldmann, D; Jobst, J; Albert, A; Albrecht, M; Reshanov, S; Schöner, A; Krieger, M; Weber, H B


    .... Here in the search for a comprehensive concept for wafer-scale graphene electronics, we present a monolithic transistor that uses the entire material system epitaxial graphene on silicon carbide (0001...

  18. Wafer-scale fabrication of glass-FEP-glass microfluidic devices for lipid bilayer experiments

    NARCIS (Netherlands)

    Bomer, Johan G.; Prokofyev, A.V.; van den Berg, Albert; le Gac, Severine


    We report a wafer-scale fabrication process for the production of glass-FEP-glass microdevices using UV-curable adhesive (NOA81) as gluing material, which is applied using a novel "spin & roll" approach. Devices are characterized for the uniformity of the gluing layer, presence of glue in the

  19. Wafer-Scale Leaning Silver Nanopillars for Molecular Detection at Ultra-Low Concentrations

    DEFF Research Database (Denmark)

    Wu, Kaiyu; Rindzevicius, Tomas; Schmidt, Michael Stenbæk


    Wafer-scale surface-enhanced Raman scattering (SERS) substrates fabricated using maskless lithography are important for scalable production targets. Large-area, leaning silver-capped silicon nanopillar (Ag NP) structures suitable for SERS molecular detection at extremely low analyte concentrations...

  20. Dimensional Control in Corner Lithography for Wafer-Scale Fabrication of Nano-Apertures

    NARCIS (Netherlands)

    Burouni, N.; Berenschot, Johan W.; Elwenspoek, Michael Curt; Tas, Niels Roelof


    In this paper we investigate a new method to fabricate 3D-oriented nanostructures in wafer scale, and apply it to fabricate a nano-apertures at the apex of a pyramid. A number of new technologies require the use of apertures to serve as electrical, nano fluidic or optical probes. Controlling the

  1. SCIL nanoimprint solutions: high-volume soft NIL for wafer scale sub-10nm resolution (United States)

    Voorkamp, R.; Verschuuren, M. A.; van Brakel, R.


    Nano-patterning materials and surfaces can add unique functionalities and properties which cannot be obtained in bulk or micro-structured materials. Examples range from hetro-epitaxy of semiconductor nano-wires to guiding cell expression and growth on medical implants. [1] Due to the cost and throughput requirements conventional nano-patterning techniques such as deep UV lithography (cost and flat substrate demands) and electron-beam lithography (cost, throughput) are not an option. Self-assembly techniques are being considered for IC manufacturing, but require nano-sized guiding patterns, which have to be fabricated in any case.[2] Additionally, the self-assembly process is highly sensitive to the environment and layer thickness, which is difficult to control on non-flat surfaces such as PV silicon wafers or III/V substrates. Laser interference lithography can achieve wafer scale periodic patterns, but is limited by the throughput due to intensity of the laser at the pinhole and only regular patterns are possible where the pattern fill fraction cannot be chosen freely due to the interference condition.[3] Nanoimprint lithography (NIL) is a promising technology for the cost effective fabrication of sub-micron and nano-patterns on large areas. The challenges for NIL are related to the technique being a contact method where a stamp which holds the patterns is required to be brought into intimate contact with the surface of the product. In NIL a strong distinction is made between the type of stamp used, either rigid or soft. Rigid stamps are made from patterned silicon, silica or plastic foils and are capable of sub-10nm resolution and wafer scale patterning. All these materials behave similar at the micro- to nm scale and require high pressures (5 - 50 Bar) to enable conformal contact to be made on wafer scales. Real world conditions such as substrate bow and particle contaminants complicate the use of rigid stamps for wafer scale areas, reducing stamp lifetime and

  2. Wafer-scale fabrication of glass-FEP-glass microfluidic devices for lipid bilayer experiments. (United States)

    Bomer, Johan G; Prokofyev, Alexander V; van den Berg, Albert; Le Gac, Séverine


    We report a wafer-scale fabrication process for the production of glass-FEP-glass microdevices using UV-curable adhesive (NOA81) as gluing material, which is applied using a novel "spin & roll" approach. Devices are characterized for the uniformity of the gluing layer, presence of glue in the microchannels, and alignment precision. Experiments on lipid bilayers with electrophysiological recordings using a model pore-forming polypeptide are demonstrated.

  3. Wafer-scale integration of sacrificial nanofluidic chips for detecting and manipulating single DNA molecules. (United States)

    Wang, Chao; Nam, Sung-Wook; Cotte, John M; Jahnes, Christopher V; Colgan, Evan G; Bruce, Robert L; Brink, Markus; Lofaro, Michael F; Patel, Jyotica V; Gignac, Lynne M; Joseph, Eric A; Rao, Satyavolu Papa; Stolovitzky, Gustavo; Polonsky, Stanislav; Lin, Qinghuang


    Wafer-scale fabrication of complex nanofluidic systems with integrated electronics is essential to realizing ubiquitous, compact, reliable, high-sensitivity and low-cost biomolecular sensors. Here we report a scalable fabrication strategy capable of producing nanofluidic chips with complex designs and down to single-digit nanometre dimensions over 200 mm wafer scale. Compatible with semiconductor industry standard complementary metal-oxide semiconductor logic circuit fabrication processes, this strategy extracts a patterned sacrificial silicon layer through hundreds of millions of nanoscale vent holes on each chip by gas-phase Xenon difluoride etching. Using single-molecule fluorescence imaging, we demonstrate these sacrificial nanofluidic chips can function to controllably and completely stretch lambda DNA in a two-dimensional nanofluidic network comprising channels and pillars. The flexible nanofluidic structure design, wafer-scale fabrication, single-digit nanometre channels, reliable fluidic sealing and low thermal budget make our strategy a potentially universal approach to integrating functional planar nanofluidic systems with logic circuits for lab-on-a-chip applications.

  4. Wafer-scale integrated micro-supercapacitors on an ultrathin and highly flexible biomedical platform. (United States)

    Maeng, Jimin; Meng, Chuizhou; Irazoqui, Pedro P


    We present wafer-scale integrated micro-supercapacitors on an ultrathin and highly flexible parylene platform, as progress toward sustainably powering biomedical microsystems suitable for implantable and wearable applications. All-solid-state, low-profile (microsystem. The system discharging rate is shown to improve by ~17 times in the presence of the integrated micro-supercapacitors. This result suggests that the integrated micro-supercapacitor technology described herein is a promising strategy for sustainably powering biomedical microsystems dedicated to implantable and wearable applications.

  5. CMOS-analogous wafer-scale nanotube-on-insulator approach for submicrometer devices and integrated circuits using aligned nanotubes. (United States)

    Ryu, Koungmin; Badmaev, Alexander; Wang, Chuan; Lin, Albert; Patil, Nishant; Gomez, Lewis; Kumar, Akshay; Mitra, Subhasish; Wong, H-S Philip; Zhou, Chongwu


    Massive aligned carbon nanotubes hold great potential but also face significant integration/assembly challenges for future beyond-silicon nanoelectronics. We report a wafer-scale processing of aligned nanotube devices and integrated circuits, including progress on essential technological components such as wafer-scale synthesis of aligned nanotubes, wafer-scale transfer of nanotubes to silicon wafers, metallic nanotube removal and chemical doping, and defect-tolerant integrated nanotube circuits. We have achieved synthesis of massive aligned nanotubes on complete 4 in. quartz and sapphire substrates, which were then transferred to 4 in. Si/SiO(2) wafers. CMOS analogous fabrication was performed to yield transistors and circuits with features down to 0.5 mum, with high current density approximately 20 muA/mum and good on/off ratios. In addition, chemical doping has been used to build fully integrated complementary inverter with a gain approximately 5, and a defect-tolerant design has been employed for NAND and NOR gates. This full-wafer approach could serve as a critical foundation for future integrated nanotube circuits.

  6. Face-to-face transfer of wafer-scale graphene films (United States)

    Gao, Libo; Ni, Guang-Xin; Liu, Yanpeng; Liu, Bo; Castro Neto, Antonio H.; Loh, Kian Ping


    Graphene has attracted worldwide interest since its experimental discovery, but the preparation of large-area, continuous graphene film on SiO2/Si wafers, free from growth-related morphological defects or transfer-induced cracks and folds, remains a formidable challenge. Growth of graphene by chemical vapour deposition on Cu foils has emerged as a powerful technique owing to its compatibility with industrial-scale roll-to-roll technology. However, the polycrystalline nature and microscopic roughness of Cu foils means that such roll-to-roll transferred films are not devoid of cracks and folds. High-fidelity transfer or direct growth of high-quality graphene films on arbitrary substrates is needed to enable wide-ranging applications in photonics or electronics, which include devices such as optoelectronic modulators, transistors, on-chip biosensors and tunnelling barriers. The direct growth of graphene film on an insulating substrate, such as a SiO2/Si wafer, would be useful for this purpose, but current research efforts remain grounded at the proof-of-concept stage, where only discontinuous, nanometre-sized islands can be obtained. Here we develop a face-to-face transfer method for wafer-scale graphene films that is so far the only known way to accomplish both the growth and transfer steps on one wafer. This spontaneous transfer method relies on nascent gas bubbles and capillary bridges between the graphene film and the underlying substrate during etching of the metal catalyst, which is analogous to the method used by tree frogs to remain attached to submerged leaves. In contrast to the previous wet or dry transfer results, the face-to-face transfer does not have to be done by hand and is compatible with any size and shape of substrate; this approach also enjoys the benefit of a much reduced density of transfer defects compared with the conventional transfer method. Most importantly, the direct growth and spontaneous attachment of graphene on the underlying

  7. Wafer scale integration of reduced graphene oxide by novel laser processing at room temperature in air (United States)

    Bhaumik, Anagh; Narayan, Jagdish


    Physical properties of reduced graphene oxide (rGO) strongly depend on the ratio of sp2 to sp3 hybridized carbon atoms, the presence of different functional groups, and the characteristics of the substrates. This research for the very first time illustrates successful wafer scale integration of 2D rGO with Cu/TiN/Si, employing pulsed laser deposition followed by laser annealing of carbon-doped copper layers using nanosecond excimer lasers. The XRD, SEM, and Raman spectroscopy measurements indicate the presence of large area rGO onto Si having Raman active vibrational modes: D, G, and 2D. A high resolution SEM depicts the morphology and formation of rGO from zone-refined carbon formed after nanosecond laser annealing. Temperature-dependent resistance data of rGO thin films follow the Efros-Shklovskii variable range hopping (VRH) model in the low-temperature region and Arrhenius conduction in the high-temperature regime. The photoluminescence spectra also reveal a less intense and broader blue fluorescence spectra, indicating the presence of miniature sized sp2 domains in the near vicinity of π* electronic states which favor the VRH transport phenomena. This wafer scale integration of rGO with Si employing a laser annealing technique will be useful for multifunctional integrated electronic devices and will open a new frontier for further extensive research in these functionalized 2D materials.

  8. Wafer-scale epitaxial graphene on SiC for sensing applications (United States)

    Karlsson, Mikael; Wang, Qin; Zhao, Yichen; Zhao, Wei; Toprak, Muhammet S.; Iakimov, Tihomir; Ali, Amer; Yakimova, Rositza; Syväjärvi, Mikael; Ivanov, Ivan G.


    The epitaxial graphene-on-silicon carbide (SiC-G) has advantages of high quality and large area coverage owing to a natural interface between graphene and SiC substrate with dimension up to 100 mm. It enables cost effective and reliable solutions for bridging the graphene-based sensors/devices from lab to industrial applications and commercialization. In this work, the structural, optical and electrical properties of wafer-scale graphene grown on 2'' 4H semi-insulating (SI) SiC utilizing sublimation process were systemically investigated with focus on evaluation of the graphene's uniformity across the wafer. As proof of concept, two types of glucose sensors based on SiC-G/Nafion/Glucose-oxidase (GOx) and SiC-G/Nafion/Chitosan/GOx were fabricated and their electrochemical properties were characterized by cyclic voltammetry (CV) measurements. In addition, a few similar glucose sensors based on graphene by chemical synthesis using modified Hummer's method were also fabricated for comparison.

  9. Uniformity study of wafer-scale InP-to-silicon hybrid integration

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Di; Bowers, John E. [University of California, Department of Electrical and Computer Engineering, Santa Barbara, CA (United States); Chapman, David C.; Oakley, Douglas C.; Napoleone, Tony; Juodawlkis, Paul W. [Massachusetts Institute of Technology, Lincoln Laboratory, Lexington, MA (United States); Li, Youli [University of California, Materials Research Laboratory, Santa Barbara, CA (United States); Brubaker, Chad; Mann, Carl [EV Group, Tempe, AZ (United States); Bar, Hanan; Raday, Omri [Intel Corporation, Jerusalem (Israel)


    In this paper we study the uniformity of up to 150 mm in diameter wafer-scale III-V epitaxial transfer to the Si-on-insulator substrate through the O{sub 2} plasma-enhanced low-temperature (300 C) direct wafer bonding. Void-free bonding is demonstrated by the scanning acoustic microscopy with sub-{mu}m resolution. The photoluminescence (PL) map shows less than 1 nm change in average peak wavelength, and even improved peak intensity (4% better) and full width at half maximum (41% better) after 150 mm in diameter epitaxial transfer. Small and uniformly distributed residual strain in all sizes of bonding, which is measured by high-resolution X-ray diffraction Omega-2Theta mapping, and employment of a two-period InP-InGaAsP superlattice at the bonding interface contributes to the improvement of PL response. Preservation of multiple quantum-well integrity is also verified by high-resolution transmission electron microscopy. (orig.)

  10. Microfluidic devices fabricated using fast wafer-scale LED-lithography patterning. (United States)

    Challa, Pavan K; Kartanas, Tadas; Charmet, Jérôme; Knowles, Tuomas P J


    Current lithography approaches underpinning the fabrication of microfluidic devices rely on UV exposure of photoresists to define microstructures in these materials. Conventionally, this objective is achieved with gas discharge mercury lamps, which are capable of producing high intensity UV radiation. However, these sources are costly, have a comparatively short lifetime, necessitate regular calibration, and require significant time to warm up prior to exposure taking place. To address these limitations we exploit advances in solid state sources in the UV range and describe a fast and robust wafer-scale laboratory exposure system relying entirely on UV-Light emitting diode (UV-LED) illumination. As an illustration of the potential of this system for fast and low-cost microfluidic device production, we demonstrate the microfabrication of a 3D spray-drying microfluidic device and a 3D double junction microdroplet maker device.

  11. Sidewall patterning—a new wafer-scale method for accurate patterning of vertical silicon structures (United States)

    Westerik, P. J.; Vijselaar, W. J. C.; Berenschot, J. W.; Tas, N. R.; Huskens, J.; Gardeniers, J. G. E.


    For the definition of wafer scale micro- and nanostructures, in-plane geometry is usually controlled by optical lithography. However, options for precisely patterning structures in the out-of-plane direction are much more limited. In this paper we present a versatile self-aligned technique that allows for reproducible sub-micrometer resolution local modification along vertical silicon sidewalls. Instead of optical lithography, this method makes smart use of inclined ion beam etching to selectively etch the top parts of structures, and controlled retraction of a conformal layer to define a hard mask in the vertical direction. The top, bottom or middle part of a structure could be selectively exposed, and it was shown that these exposed regions can, for example, be selectively covered with a catalyst, doped, or structured further.

  12. High-mobility three-atom-thick semiconducting films with wafer-scale homogeneity. (United States)

    Kang, Kibum; Xie, Saien; Huang, Lujie; Han, Yimo; Huang, Pinshane Y; Mak, Kin Fai; Kim, Cheol-Joo; Muller, David; Park, Jiwoong


    The large-scale growth of semiconducting thin films forms the basis of modern electronics and optoelectronics. A decrease in film thickness to the ultimate limit of the atomic, sub-nanometre length scale, a difficult limit for traditional semiconductors (such as Si and GaAs), would bring wide benefits for applications in ultrathin and flexible electronics, photovoltaics and display technology. For this, transition-metal dichalcogenides (TMDs), which can form stable three-atom-thick monolayers, provide ideal semiconducting materials with high electrical carrier mobility, and their large-scale growth on insulating substrates would enable the batch fabrication of atomically thin high-performance transistors and photodetectors on a technologically relevant scale without film transfer. In addition, their unique electronic band structures provide novel ways of enhancing the functionalities of such devices, including the large excitonic effect, bandgap modulation, indirect-to-direct bandgap transition, piezoelectricity and valleytronics. However, the large-scale growth of monolayer TMD films with spatial homogeneity and high electrical performance remains an unsolved challenge. Here we report the preparation of high-mobility 4-inch wafer-scale films of monolayer molybdenum disulphide (MoS2) and tungsten disulphide, grown directly on insulating SiO2 substrates, with excellent spatial homogeneity over the entire films. They are grown with a newly developed, metal-organic chemical vapour deposition technique, and show high electrical performance, including an electron mobility of 30 cm(2) V(-1) s(-1) at room temperature and 114 cm(2) V(-1) s(-1) at 90 K for MoS2, with little dependence on position or channel length. With the use of these films we successfully demonstrate the wafer-scale batch fabrication of high-performance monolayer MoS2 field-effect transistors with a 99% device yield and the multi-level fabrication of vertically stacked transistor devices for three

  13. Wafer-scale thin encapsulated two-dimensional nanochannels and its application toward visualization of single molecules

    NARCIS (Netherlands)

    Hoang Thi Hanh, H.T.H.; Tong, H.D.; Segers-Nolten, Gezina M.J.; Tas, Niels Roelof; Subramaniam, Vinod; Elwenspoek, Michael Curt


    We present a new and simple approach to fabricate wafer-scale, thin encapsulated, two-dimensional nanochannels by using conventional surface-micromachining technology and thin-film evaporation. The key steps to the realization of two-dimensional nanochannels are a fine etching of a sacrificial layer

  14. Wafer-scale thin encapsulated two-dimensional nanochannels and its application toward visualization of single molecules.

    NARCIS (Netherlands)

    Hoang, H.T.; Tong, H.D.; Segers-Nolten, I.M.; Tas, N.R.; Subramaniam, V.; Elwenspoek, M.C.


    We present a new and simple approach to fabricate wafer-scale, thin encapsulated, two-dimensional nanochannels by using conventional surface-micromachining technology and thin-film evaporation. The key steps to the realization of two-dimensional nanochannels are a fine etching of a sacrificial layer

  15. Layer-by-layer assembly of two-dimensional materials into wafer-scale heterostructures (United States)

    Kang, Kibum; Lee, Kan-Heng; Han, Yimo; Gao, Hui; Xie, Saien; Muller, David A.; Park, Jiwoong


    High-performance semiconductor films with vertical compositions that are designed to atomic-scale precision provide the foundation for modern integrated circuitry and novel materials discovery. One approach to realizing such films is sequential layer-by-layer assembly, whereby atomically thin two-dimensional building blocks are vertically stacked, and held together by van der Waals interactions. With this approach, graphene and transition-metal dichalcogenides--which represent one- and three-atom-thick two-dimensional building blocks, respectively--have been used to realize previously inaccessible heterostructures with interesting physical properties. However, no large-scale assembly method exists at present that maintains the intrinsic properties of these two-dimensional building blocks while producing pristine interlayer interfaces, thus limiting the layer-by-layer assembly method to small-scale proof-of-concept demonstrations. Here we report the generation of wafer-scale semiconductor films with a very high level of spatial uniformity and pristine interfaces. The vertical composition and properties of these films are designed at the atomic scale using layer-by-layer assembly of two-dimensional building blocks under vacuum. We fabricate several large-scale, high-quality heterostructure films and devices, including superlattice films with vertical compositions designed layer-by-layer, batch-fabricated tunnel device arrays with resistances that can be tuned over four orders of magnitude, band-engineered heterostructure tunnel diodes, and millimetre-scale ultrathin membranes and windows. The stacked films are detachable, suspendable and compatible with water or plastic surfaces, which will enable their integration with advanced optical and mechanical systems.

  16. Wafer-Scale High-Throughput Ordered Growth of Vertically Aligned ZnO Nanowire Arrays

    KAUST Repository

    Wei, Yaguang


    This article presents an effective approach for patterned growth of vertically aligned ZnO nanowire (NW) arrays with high throughput and low cost at wafer scale without using cleanroom technology. Periodic hole patterns are generated using laser interference lithography on substrates coated with the photoresist SU-8. ZnO NWs are selectively grown through the holes via a low-temperature hydrothermal method without using a catalyst and with a superior control over orientation, location/density, and as-synthesized morphology. The development of textured ZnO seed layers for replacing single crystalline GaN and ZnO substrates extends the large-scale fabrication of vertically aligned ZnO NW arrays on substrates of other materials, such as polymers, Si, and glass. This combined approach demonstrates a novel method of manufacturing large-scale patterned one-dimensional nanostructures on various substrates for applications in energy harvesting, sensing, optoelectronics, and electronic devices. © 2010 American Chemical Society.

  17. Toward the synthesis of wafer-scale single-crystal graphene on copper foils. (United States)

    Yan, Zheng; Lin, Jian; Peng, Zhiwei; Sun, Zhengzong; Zhu, Yu; Li, Lei; Xiang, Changsheng; Samuel, E Loïc; Kittrell, Carter; Tour, James M


    In this research, we constructed a controlled chamber pressure CVD (CP-CVD) system to manipulate graphene's domain sizes and shapes. Using this system, we synthesized large (~4.5 mm(2)) single-crystal hexagonal monolayer graphene domains on commercial polycrystalline Cu foils (99.8% purity), indicating its potential feasibility on a large scale at low cost. The as-synthesized graphene had a mobility of positive charge carriers of ~11,000 cm(2) V(-1) s(-1) on a SiO(2)/Si substrate at room temperature, suggesting its comparable quality to that of exfoliated graphene. The growth mechanism of Cu-based graphene was explored by studying the influence of varied growth parameters on graphene domain sizes. Cu pretreatments, electrochemical polishing, and high-pressure annealing are shown to be critical for suppressing graphene nucleation site density. A pressure of 108 Torr was the optimal chamber pressure for the synthesis of large single-crystal monolayer graphene. The synthesis of one graphene seed was achieved on centimeter-sized Cu foils by optimizing the flow rate ratio of H(2)/CH(4). This work should provide clear guidelines for the large-scale synthesis of wafer-scale single-crystal graphene, which is essential for the optimized graphene device fabrication.

  18. Versatile pattern generation of periodic, high aspect ratio Si nanostructure arrays with sub-50-nm resolution on a wafer scale. (United States)

    Ho, Jian-Wei; Wee, Qixun; Dumond, Jarrett; Tay, Andrew; Chua, Soo-Jin


    We report on a method of fabricating variable patterns of periodic, high aspect ratio silicon nanostructures with sub-50-nm resolution on a wafer scale. The approach marries step-and-repeat nanoimprint lithography (NIL) and metal-catalyzed electroless etching (MCEE), enabling near perfectly ordered Si nanostructure arrays of user-defined patterns to be controllably and rapidly generated on a wafer scale. Periodic features possessing circular, hexagonal, and rectangular cross-sections with lateral dimensions down to sub-50 nm, in hexagonal or square array configurations and high array packing densities up to 5.13 × 107 structures/mm2 not achievable by conventional UV photolithography are fabricated using this top-down approach. By suitably tuning the duration of catalytic etching, variable aspect ratio Si nanostructures can be formed. As the etched Si pattern depends largely on the NIL mould which is patterned by electron beam lithography (EBL), the technique can be used to form patterns not possible with self-assembly methods, nanosphere, and interference lithography for replication on a wafer scale. Good chemical resistance of the nanoimprinted mask and adhesion to the Si substrate facilitate good pattern transfer and preserve the smooth top surface morphology of the Si nanostructures as shown in TEM. This approach is suitable for generating Si nanostructures of controlled dimensions and patterns, with high aspect ratio on a wafer level suitable for semiconductor device production.

  19. Corrugation Architecture Enabled Ultraflexible Wafer-Scale High-Efficiency Monocrystalline Silicon Solar Cell

    KAUST Repository

    Bahabry, Rabab R.


    Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large-scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon-based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor-based integration strategy where corrugation architecture enables ultraflexible and low-cost solar cell modules from bulk monocrystalline large-scale (127 × 127 cm) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 μm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon-based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 μm of the back contacts is shown that carries the solar cells segments.

  20. Cascading wafer-scale integrated graphene complementary inverters under ambient conditions. (United States)

    Rizzi, Laura Giorgia; Bianchi, Massimiliano; Behnam, Ashkan; Carrion, Enrique; Guerriero, Erica; Polloni, Laura; Pop, Eric; Sordan, Roman


    The fundamental building blocks of digital electronics are logic gates which must be capable of cascading such that more complex logic functions can be realized. Here we demonstrate integrated graphene complementary inverters which operate with the same input and output voltage logic levels, thus allowing cascading. We obtain signal matching under ambient conditions with inverters fabricated from wafer-scale graphene grown by chemical vapor deposition (CVD). Monolayer graphene was incorporated in self-aligned field-effect transistors in which the top gate overlaps with the source and drain contacts. This results in full-channel gating and leads to the highest low-frequency voltage gain reported so far in top-gated CVD graphene devices operating in air ambient, A(v) ∼ -5. Such gain enabled logic inverters with the same voltage swing of 0.56 V at their input and output. Graphene inverters could find their way in realistic applications where high-speed operation is desired but power dissipation is not a concern, similar to emitter-coupled logic.

  1. Atomic layer lithography of wafer-scale nanogap arrays for extreme confinement of electromagnetic waves. (United States)

    Chen, Xiaoshu; Park, Hyeong-Ryeol; Pelton, Matthew; Piao, Xianji; Lindquist, Nathan C; Im, Hyungsoon; Kim, Yun Jung; Ahn, Jae Sung; Ahn, Kwang Jun; Park, Namkyoo; Kim, Dai-Sik; Oh, Sang-Hyun


    Squeezing light through nanometre-wide gaps in metals can lead to extreme field enhancements, nonlocal electromagnetic effects and light-induced electron tunnelling. This intriguing regime, however, has not been readily accessible to experimentalists because of the lack of reliable technology to fabricate uniform nanogaps with atomic-scale resolution and high throughput. Here we introduce a new patterning technology based on atomic layer deposition and simple adhesive-tape-based planarization. Using this method, we create vertically oriented gaps in opaque metal films along the entire contour of a millimetre-sized pattern, with gap widths as narrow as 9.9 Å, and pack 150,000 such devices on a 4-inch wafer. Electromagnetic waves pass exclusively through the nanogaps, enabling background-free transmission measurements. We observe resonant transmission of near-infrared waves through 1.1-nm-wide gaps (λ/1,295) and measure an effective refractive index of 17.8. We also observe resonant transmission of millimetre waves through 1.1-nm-wide gaps (λ/4,000,000) and infer an unprecedented field enhancement factor of 25,000.

  2. Tailoring the graphene/silicon carbide interface for monolithic wafer-scale electronics. (United States)

    Hertel, S; Waldmann, D; Jobst, J; Albert, A; Albrecht, M; Reshanov, S; Schöner, A; Krieger, M; Weber, H B


    Graphene is an outstanding electronic material, predicted to have a role in post-silicon electronics. However, owing to the absence of an electronic bandgap, graphene switching devices with high on/off ratio are still lacking. Here in the search for a comprehensive concept for wafer-scale graphene electronics, we present a monolithic transistor that uses the entire material system epitaxial graphene on silicon carbide (0001). This system consists of the graphene layer with its vanishing energy gap, the underlying semiconductor and their common interface. The graphene/semiconductor interfaces are tailor-made for ohmic as well as for Schottky contacts side-by-side on the same chip. We demonstrate normally on and normally off operation of a single transistor with on/off ratios exceeding 10(4) and no damping at megahertz frequencies. In its simplest realization, the fabrication process requires only one lithography step to build transistors, diodes, resistors and eventually integrated circuits without the need of metallic interconnects.

  3. Wafer-scale design of lightweight and transparent electronics that wraps around hairs (United States)

    Salvatore, Giovanni A.; Münzenrieder, Niko; Kinkeldei, Thomas; Petti, Luisa; Zysset, Christoph; Strebel, Ivo; Büthe, Lars; Tröster, Gerhard


    Electronics on very thin substrates have shown remarkable bendability, conformability and lightness, which are important attributes for biological tissues sensing, wearable or implantable devices. Here we propose a wafer-scale process scheme to realize ultra flexible, lightweight and transparent electronics on top of a 1-μm thick parylene film that is released from the carrier substrate after the dissolution in water of a polyvinyl- alcohol layer. The thin substrate ensures extreme flexibility, which is demonstrated by transistors that continue to work when wrapped around human hairs. In parallel, the use of amorphous oxide semiconductor and high-K dielectric enables the realization of analogue amplifiers operating at 12 V and above 1 MHz. Electronics can be transferred on any object, surface and on biological tissues like human skin and plant leaves. We foresee a potential application as smart contact lenses, covered with light, transparent and flexible devices, which could serve to monitor intraocular pressure for glaucoma disease.

  4. Wafer-Scale Ultrathin Two-Dimensional Conjugated Microporous Polymers: Preparation and Application in Heterostructure Devices. (United States)

    Liu, Zhengdong; Song, Mengya; Ju, Shang; Huang, Xiao; Wang, Xiangjing; Shi, Xiaotong; Zhu, Ya; Wang, Zhan; Chen, Jie; Li, Hai; Cheng, Yingchun; Xie, Linghai; Liu, Juqing; Huang, Wei


    In this work, we report a universal surface-assisted oxidative polymerization strategy for wafer-scale fabrication of ultrathin two-dimensional conjugated microporous polymers (2D CMPs) on arbitrary substrates under ambient conditions. Three kinds of 2D CMPs with average thickness of 1.5-3.6 nm were prepared on SiO2/Si substrates by using carbazole based monomers. Moreover, 2D CMPs can be grown on reduced graphene oxide (rGO) substrate to construct large-area 2D CMP/rGO heterostructure. As a proof-of-concept demonstration, an organic vertical field-effect transistor based on 2D CMP/rGO heterostructures was fabricated, which exhibited typical p-type behavior with high reproducibility and on/off current ratio. Most importantly, the direct growth of large-area 2D CMPs on arbitrary substrates is compatible with the conventional processes in the semiconductor industry, and therefore is expected to expedite the development of 2D CMPs as building blocks for construction of practical electronic devices.

  5. Wafer-scale synthesis of monolayer and few-layer MoS2 via thermal vapor sulfurization (United States)

    Robertson, John; Liu, Xue; Yue, Chunlei; Escarra, Matthew; Wei, Jiang


    Monolayer molybdenum disulfide (MoS2) is an atomically thin, direct bandgap semiconductor crystal potentially capable of miniaturizing optoelectronic devices to an atomic scale. However, the development of 2D MoS2-based optoelectronic devices depends upon the existence of a high optical quality and large-area monolayer MoS2 synthesis technique. To address this need, we present a thermal vapor sulfurization (TVS) technique that uses powder MoS2 as a sulfur vapor source. The technique reduces and stabilizes the flow of sulfur vapor, enabling monolayer wafer-scale MoS2 growth. MoS2 thickness is also controlled with great precision; we demonstrate the ability to synthesize MoS2 sheets between 1 and 4 layers thick, while also showing the ability to create films with average thickness intermediate between integer layer numbers. The films exhibit wafer-scale coverage and uniformity, with electrical quality varying depending on the final thickness of the grown MoS2. The direct bandgap of grown monolayer MoS2 is analyzed using internal and external photoluminescence quantum efficiency. The photoluminescence quantum efficiency is shown to be competitive with untreated exfoliated MoS2 monolayer crystals. The ability to consistently grow wafer-scale monolayer MoS2 with high optical quality makes this technique a valuable tool for the development of 2D optoelectronic devices such as photovoltaics, detectors, and light emitters.

  6. Electronic and optoelectronic devices based on chirality-enriched wafer-scale single-wall carbon nanotube thin films (United States)

    Gao, Weilu; He, Xiaowei; Xie, Lijuan; Zhang, Qi; Haroz, Erik; Doorn, Stephen K.; Kono, Junichiro


    The unique and rich material properties of single-wall carbon nanotubes (SWCNTs) make them attractive for nano-electronic and optoelectronic applications. Slight changes in tube diameter and wrapping angle, defined by the chirality indices (n, m), can dramatically modify the bandstructure, which can be utilized for designing devices with tailored properties. However, it remains to be a challenge to fabricate macroscopic, single-chirality devices. Here, we introduce a simple way of producing chirality-enriched wafer-scale SWCNT films by combining recently developed solution-based polymer-modified sorting method and vacuum filtration. The produced thin films can be easily transferred onto any substrate to have a CMOS compatible wafer. We fabricated a transistor of (6,5)-enriched SWCNTs with an on/off ratio >103. Large-scale photothermoelectric-effect-based and photovoltaic-effect-based photodetectors made of (6,6)- and (6,5)-enriched films, respectively, will also be discussed.

  7. Fabrication of WS2/GaN p-n Junction by Wafer-Scale WS2 Thin Film Transfer (United States)

    Yu, Yang; Fong, Patrick W. K.; Wang, Shifeng; Surya, Charles


    High quality wafer-scale free-standing WS2 grown by van der Waals rheotaxy (vdWR) using Ni as a texture promoting layer is reported. The microstructure of vdWR grown WS2 was significantly modified from mixture of crystallites with their c-axes both parallel to (type I) and perpendicular to (type II) the substrate to large type II crystallites. Wafer-scale transfer of vdWR grown WS2 onto different substrates by an etching-free technique was demonstrated for the first time that utilized the hydrophobic property of WS2 and hydrophilic property of sapphire. Our results show that vdWR is a reliable technique to obtain type-II textured crystallites in WS2, which is the key factor for the wafer-scale etching-free transfer. The transferred films were found to be free of observable wrinkles, cracks, or polymer residues. High quality p-n junctions fabricated by room-temperature transfer of the p-type WS2 onto an n-type GaN was demonstrated with a small leakage current density of 29.6 μA/cm2 at −1 V which shows superior performances compared to the directly grown WS2/GaN heterojunctions. PMID:27897210

  8. Field-effect transistors based on wafer-scale, highly uniform few-layer p-type WSe2 (United States)

    Campbell, Philip M.; Tarasov, Alexey; Joiner, Corey A.; Tsai, Meng-Yen; Pavlidis, Georges; Graham, Samuel; Ready, W. Jud; Vogel, Eric M.


    The synthesis of few-layer tungsten diselenide (WSe2) via chemical vapor deposition typically results in highly non-uniform thickness due to nucleation initiated growth of triangular domains. In this work, few-layer p-type WSe2 with wafer-scale thickness and electrical uniformity is synthesized through direct selenization of thin films of e-beam evaporated W on SiO2 substrates. Raman maps over a large area of the substrate show small variations in the main peak position, indicating excellent thickness uniformity across several square centimeters. Additionally, field-effect transistors fabricated from the wafer-scale WSe2 films demonstrate uniform electrical performance across the substrate. The intrinsic field-effect mobility of the films at a carrier concentration of 3 × 1012 cm-2 is 10 cm2 V-1 s-1. The unprecedented uniformity of the WSe2 on wafer-scale substrates provides a substantial step towards producing manufacturable materials that are compatible with conventional semiconductor fabrication processes.

  9. Length Scale Dependence of Periodic Textures for Photoabsorption Enhancement in Ultra-thin Silicon Foils and Thick Wafers

    CERN Document Server

    Kumar, K; Liu, G; Nogami, J; Kherani, N P


    In this paper, we simulate a front surface inverted pyramidal grating texture on 2 to 400 micron thick silicon and optimize it to derive maximum photocurrent density from the cell. We identify a one size fits all front grating period of 1000 nm that leads to maximum photo-absorption of normally incident AM1.5g solar spectrum in silicon (configured with a back surface reflector) irrespective of the thickness of the crystalline silicon absorbing layer. With the identification of such universally optimized periodicity for the case of an inverted pyramidal grating texture, a common fabrication process can be designed to manufacture high-efficiency devices on crystalline silicon regardless of wafer thickness. In order to validate the results of the simulation, we fabricated high resolution inverted pyramidal textures on a 400 micron thick silicon wafer with electron beam lithography to compare the reflectance from submicron and wavelength scale periodic textures. The experimental reflectance measurements on textur...

  10. Terahertz wafer-scale mobility mapping of graphene on insulating substrates without a gate

    DEFF Research Database (Denmark)

    Buron, Jonas Due; Mackenzie, David M. A.; Petersen, Dirch Hjorth


    carriers and these parameters are directly compared to van der Pauw device measurements on the same wafer. The technique is compatible with all substrate materials that exhibit a reasonably low absorption coefficient for terahertz radiation. This includes many materials used for transferring CVD graphene...

  11. Wafer-Scale Nanopillars Derived from Block Copolymer Lithography for Surface-Enhanced Raman Spectroscopy

    DEFF Research Database (Denmark)

    Li, Tao; Wu, Kaiyu; Rindzevicius, Tomas


    We report a novel nanofabrication process via block copolymer lithography using solvent vapor annealing. The nanolithography process is facile and scalable, enabling fabrication of highly ordered periodic patterns over entire wafers as substrates for surface-enhanced Raman spectroscopy (SERS). Di...

  12. Very large scale heterogeneous integration (VLSHI) and wafer-level vacuum packaging for infrared bolometer focal plane arrays (United States)

    Forsberg, Fredrik; Roxhed, Niclas; Fischer, Andreas C.; Samel, Björn; Ericsson, Per; Hoivik, Nils; Lapadatu, Adriana; Bring, Martin; Kittilsland, Gjermund; Stemme, Göran; Niklaus, Frank


    Imaging in the long wavelength infrared (LWIR) range from 8 to 14 μm is an extremely useful tool for non-contact measurement and imaging of temperature in many industrial, automotive and security applications. However, the cost of the infrared (IR) imaging components has to be significantly reduced to make IR imaging a viable technology for many cost-sensitive applications. This paper demonstrates new and improved fabrication and packaging technologies for next-generation IR imaging detectors based on uncooled IR bolometer focal plane arrays. The proposed technologies include very large scale heterogeneous integration for combining high-performance, SiGe quantum-well bolometers with electronic integrated read-out circuits and CMOS compatible wafer-level vacuum packing. The fabrication and characterization of bolometers with a pitch of 25 μm × 25 μm that are arranged on read-out-wafers in arrays with 320 × 240 pixels are presented. The bolometers contain a multi-layer quantum well SiGe thermistor with a temperature coefficient of resistance of -3.0%/K. The proposed CMOS compatible wafer-level vacuum packaging technology uses Cu-Sn solid-liquid interdiffusion (SLID) bonding. The presented technologies are suitable for implementation in cost-efficient fabless business models with the potential to bring about the cost reduction needed to enable low-cost IR imaging products for industrial, security and automotive applications.

  13. Simple, Fast, and Cost-Effective Fabrication of Wafer-Scale Nanohole Arrays on Silicon for Antireflection

    Directory of Open Access Journals (Sweden)

    Di Di


    Full Text Available A simple, fast, and cost-effective method was developed in this paper for the high-throughput fabrication of nanohole arrays on silicon (Si, which is utilized for antireflection. Wafer-scale polystyrene (PS monolayer colloidal crystal was developed as templates by spin-coating method. Metallic shadow mask was prepared by lifting off the oxygen etched PS beads from the deposited chromium film. Nanohole arrays were fabricated by Si dry etching. A series of nanohole arrays were fabricated with the similar diameter but with different depth. It is found that the maximum depth of the Si-hole was determined by the diameter of the Cr-mask. The antireflection ability of these Si-hole arrays was investigated. The results show that the reflection decreases with the depth of the Si-hole. The deepest Si-hole arrays show the best antireflection ability (reflection 600 nm, which was about 28 percent of the nonpatterned silicon wafer’s reflection. The proposed method has the potential for high-throughput fabrication of patterned Si wafer, and the low reflectivity allows the application of these wafers in crystalline silicon solar cells.

  14. Wafer-scale fabrication of polymer-based microdevices via injection molding and photolithographic micropatterning protocols. (United States)

    Lee, Dae-Sik; Yang, Haesik; Chung, Kwang-Hyo; Pyo, Hyeon-Bong


    Because of their broad applications in biomedical analysis, integrated, polymer-based microdevices incorporating micropatterned metallic and insulating layers are significant in contemporary research. In this study, micropatterns for temperature sensing and microelectrode sets for electroanalysis have been implemented on an injection-molded thin polymer membrane by employing conventional semiconductor processing techniques (i.e., standard photolithographic methods). Cyclic olefin copolymer (COC) is chosen as the polymer substrate because of its high chemical and thermal stability. A COC 5-in. wafer (1-mm thickness) is manufactured using an injection molding method, in which polymer membranes (approximately 130 microm thick and 3 mm x 6 mm in area) are implemented simultaneously in order to reduce local thermal mass around micropatterned heaters and temperature sensors. The highly polished surface (approximately 4 nm within 40 microm x 40 microm area) of the fabricated COC wafer as well as its good resistance to typical process chemicals makes it possible to use the standard photolithographic and etching protocols on the COC wafer. Gold micropatterns with a minimum 5-microm line width are fabricated for making microheaters, temperature sensors, and microelectrodes. An insulating layer of aluminum oxide (Al2O3) is prepared at a COC-endurable low temperature (approximately 120 degrees C) by using atomic layer deposition and micropatterning for the electrode contacts. The fabricated microdevice for heating and temperature sensing shows improved performance of thermal isolation, and microelectrodes display good electrochemical performances for electrochemical sensors. Thus, this novel 5-in. wafer-level microfabrication method is a simple and cost-effective protocol to prepare polymer substrate and demonstrates good potential for application to highly integrated and miniaturized biomedical devices.

  15. Bottom-Up Nano-heteroepitaxy of Wafer-Scale Semipolar GaN on (001) Si

    KAUST Repository

    Hus, Jui Wei


    Semipolar {101¯1} InGaN quantum wells are grown on (001) Si substrates with an Al-free buffer and wafer-scale uniformity. The novel structure is achieved by a bottom-up nano-heteroepitaxy employing self-organized ZnO nanorods as the strain-relieving layer. This ZnO nanostructure unlocks the problems encountered by the conventional AlN-based buffer, which grows slowly and contaminates the growth chamber. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A Wafer scale active pixel CMOS image sensor for generic x-ray radiology (United States)

    Scheffer, Danny


    This paper describes a CMOS Active Pixel Image Sensor developed for generic X-ray imaging systems using standard CMOS technology and an active pixel architecture featuring low noise and a high sensitivity. The image sensor has been manufactured in a standard 0.35 μm technology using 8" wafers. The resolution of the sensor is 3360x3348 pixels of 40x40 μm2 each. The diagonal of the sensor measures little over 190 mm. The paper discusses the floor planning, stitching diagram, and the electro-optical performance of the sensor that has been developed.

  17. Plasma-Induced Wafer-Scale Self-Assembly of Silver Nanoparticles and Application to Biochemical Sensing

    Directory of Open Access Journals (Sweden)

    Yunbo Shi


    Full Text Available In this work, the wafer-scale silver nanoparticles fabricated by a self-assembly method was demonstrated based on a magnetron sputtering and plasma treatment process. Silver nanoparticles of different sizes and shapes were prepared, and the effects of the plasma treatment time, plasma gas composition, and power were systematically investigated to develop a method for low-cost and large-scale fabrication of silver nanoparticles. Furthermore, the surface-enhanced Raman scattering experiments: crystal violet, as the probe, was absorbed on the silver nanoparticles film of different size and density, and get the phenomena of surface-enhanced Raman scattering and surface-enhanced fluorescence. The results show that the proposed technique provides a rapid method for the fabrication of silver nanomaterial; the method is adaptable to large-scale production and is compatible with the fabrication of other materials and biosensors.

  18. Large-scale fabrication of wafer-size colloidal crystals, macroporous polymers and nanocomposites by spin-coating. (United States)

    Jiang, Peng; McFarland, Michael J


    This paper reports a simple spin-coating technique for rapidly fabricating three types of technologically important materials--colloidal crystal, macroporous polymer, and polymeric nanocomposite, each with high crystalline qualities and wafer-scale sizes. Dispersion of monodisperse silica colloids in triacrylate monomers is spin-coated onto a variety of substrates. Shear-induced ordering and subsequent polymerization lead to the formation of three-dimensionally (3D) ordered colloidal crystals trapped inside a polymer matrix. The thickness of as-synthesized colloidal crystal-polymer nanocomposite is highly uniform and can be controlled simply by changing the spin speed and time. Selective removal of the polymer matrix and silica spheres lead to the formation of large-area colloidal crystals and macroporous polymers, respectively. The wafer-scale process is compatible with standard semiconductor microfabrication, as multiple micrometer-sized patterns can be created simultaneously for potential device applications. Normal-incidence transmission spectra in the visible and near-infrared regions show distinct peaks due to Bragg diffraction from 3D ordered structures. The spin-coating process opens a new route to the fundamental studies of shear-induced crystallization, melting and relaxation. Copyright 2004 American Chemical Society

  19. Wafer-level chip-scale packaging analog and power semiconductor applications

    CERN Document Server

    Qu, Shichun


    This book presents a state-of-art and in-depth overview in analog and power WLCSP design, material characterization, reliability, and modeling. Recent advances in analog and power electronic WLCSP packaging are presented based on the development of analog technology and power device integration. The book covers in detail how advances in semiconductor content, analog and power advanced WLCSP design, assembly, materials, and reliability have co-enabled significant advances in fan-in and fan-out with redistributed layer (RDL) of analog and power device capability during recent years. Along with new analog and power WLCSP development, the role of modeling is a key to assure successful package design. An overview of the analog and power WLCSP modeling and typical thermal, electrical, and stress modeling methodologies is also provided. This book also: ·         Covers the development of wafer-level power discrete packaging with regular wafer-level design concepts and directly bumping technology ·    �...

  20. Stationary Optical Concentrator Designs and Wafer Scale Monolithic Integration of Semiconductor Devices for Next Generation Photovoltaic Panels (United States)

    Kim, Jung Min

    A major barrier in utilizing solar energy for large scale deployment is the cost of the photovoltaic (PV) systems. Several approaches have been used for the cost reduction such as by modifying PV system designs in addition to enhancing the efficiency of solar cells. Due to the high cost of materials, minimizing the use of solar cells such as in concentrator type systems is highly attractive for reducing the cost of the PV modules by focusing the incident light onto the PV cell. However concentrator PV systems (CPV) require constant tracking of the sun and hence are complex in design and expensive to operate, except in limited situations such as large scale PV power plants. It is desirable to design new concentrator type systems that do not require continuous tracking of the sun. These systems could ultimately reduce the PV system cost to a minimum while maximizing the power conversion efficiency. In this thesis we propose a simple design for a stationary concentrator photovoltaic (SCPV) system that could significantly reduce the cost of generating electricity using PV devices. Using optical ray tracing simulations, we have been able to design SCPV systems that could reduce the PV module cost by 2--10 times without compromising on the power conversion efficiency of the system. Another alternative approach for sustainable high efficiency PV system design is to develop low cost PV cells for terrestrial applications. To meet the demands of low cost and large scale production, larger and thinner (or flexible) substrates are required. We demonstrated the feasibility of fabricating monolithic interconnected PV devices at the wafer scale (2 inch wafers). In this study, GaSb PV cells grown on semi-insulating GaAs were used as the model material. Crucial device fabrication steps such as a selective etching process have been developed that is necessary for isolating individual devices on the wafer and interconnecting them with sub-micron scale accuracy. Selective etching of

  1. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication. (United States)

    Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert


    In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80-100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes.

  2. Wafer scale millimeter-wave integrated circuits based on epitaxial graphene in high data rate communication (United States)

    Habibpour, Omid; He, Zhongxia Simon; Strupinski, Wlodek; Rorsman, Niklas; Zirath, Herbert


    In recent years, the demand for high data rate wireless communications has increased dramatically, which requires larger bandwidth to sustain multi-user accessibility and quality of services. This can be achieved at millimeter wave frequencies. Graphene is a promising material for the development of millimeter-wave electronics because of its outstanding electron transport properties. Up to now, due to the lack of high quality material and process technology, the operating frequency of demonstrated circuits has been far below the potential of graphene. Here, we present monolithic integrated circuits based on epitaxial graphene operating at unprecedented high frequencies (80-100 GHz). The demonstrated circuits are capable of encoding/decoding of multi-gigabit-per-second information into/from the amplitude or phase of the carrier signal. The developed fabrication process is scalable to large wafer sizes.

  3. HED-TIE: A wafer-scale approach for fabricating hybrid electronic devices with trench isolated electrodes (United States)

    Banerjee, Sreetama; Bülz, Daniel; Solonenko, Dmytro; Reuter, Danny; Deibel, Carsten; Hiller, Karla; Zahn, Dietrich R. T.; Salvan, Georgeta


    Organic-inorganic hybrid electronic devices (HEDs) offer opportunities for functionalities that are not easily obtainable with either organic or inorganic materials individually. In the strive for down-scaling the channel length in planar geometry HEDs, the best results were achieved with electron beam lithography or nanoimprint lithography. Their application on the wafer level is, however, cost intensive and time consuming. Here, we propose trench isolated electrode (TIE) technology as a fast, cost effective, wafer-level approach for the fabrication of planar HEDs with electrode gaps in the range of 100 nm. We demonstrate that the formation of the organic channel can be realized by deposition from solution as well as by the thermal evaporation of organic molecules. To underline one key feature of planar HED-TIEs, namely full accessibility of the active area of the devices by external stimuli such as light, 6,13-bis (triisopropylsilylethynyl) (TIPS)-pentacene/Au HED-TIEs are successfully tested for possible application as hybrid photodetectors in the visible spectral range.

  4. Deterministic patterned growth of high-mobility large-crystal graphene: a path towards wafer scale integration (United States)

    Miseikis, Vaidotas; Bianco, Federica; David, Jérémy; Gemmi, Mauro; Pellegrini, Vittorio; Romagnoli, Marco; Coletti, Camilla


    We demonstrate rapid deterministic (seeded) growth of large single-crystals of graphene by chemical vapour deposition (CVD) utilising pre-patterned copper substrates with chromium nucleation sites. Arrays of graphene single-crystals as large as several hundred microns are grown with a periodicity of up to 1 mm. The graphene is transferred to target substrates using aligned and contamination- free semi-dry transfer. The high quality of the synthesised graphene is confirmed by Raman spectroscopy and transport measurements, demonstrating room-temperature carrier mobility of 21 000 cm2 V-1 s-1 when transferred on top of hexagonal boron nitride. By tailoring the nucleation of large single-crystals according to the desired device geometry, it will be possible to produce complex device architectures based on single-crystal graphene, thus paving the way to the adoption of CVD graphene in wafer-scale fabrication.

  5. Wafer-scale processing technology for monolithically integrated GaSb thermophotovoltaic device array on semi-insulating GaAs substrate (United States)

    Kim, Jung Min; Dutta, Partha S.; Brown, Eric; Borrego, Jose M.; Greiff, Paul


    This paper presents the entire fabrication and processing steps necessary for wafer scale monolithic integration of series interconnected GaSb devices grown on semi-insulating GaAs substrates. A device array has been fabricated on complete 50 mm (2 inch) diameter wafer using standard photolithography, wet chemical selective etching, dielectric deposition and single-sided metallization. For proof of concept of the wafer-scale feasibility of this process, six large-area series interconnected GaSb p-n junction thermophotovoltaic cells with each cell consisting of 24 small-area devices have been fabricated and characterized for its electrical connectivity. The fabrication process presented in this paper can be used for optoelectronic and electronic device technologies based on GaSb and related antimonide based compound semiconductors.

  6. 12-inch-wafer-scale CMOS active-pixel sensor for digital mammography (United States)

    Heo, Sung Kyn; Kosonen, Jari; Hwang, Sung Ha; Kim, Tae Woo; Yun, Seungman; Kim, Ho Kyung


    This paper describes the development of an active-pixel sensor (APS) panel, which has a field-of-view of 23.1×17.1 cm and features 70-μm-sized pixels arranged in a 3300×2442 array format, for digital mammographic applications. The APS panel was realized on 12-inch wafers based on the standard complementary metal-oxide-semiconductor (CMOS) technology without physical tiling processes of several small-area sensor arrays. Electrical performance of the developed panel is described in terms of dark current, full-well capacity and leakage current map. For mammographic imaging, the optimized CsI:Tl scintillator is experimentally determined by being combined with the developed panel and analyzing im aging characteristics, such as modulation-transfer function, noise-power spectrum, detective quantum efficiency, image l ag, and contrast-detail analysis by using the CDMAM 3.4 phantom. With these results, we suggest that the developed CMOS-based detector can be used for conventional and advanced digital mammographic applications.

  7. Wafer-scale single-domain-like graphene by defect-selective atomic layer deposition of hexagonal ZnO (United States)

    Park, Kyung Sun; Kim, Sejoon; Kim, Hongbum; Kwon, Deokhyeon; Koo Lee, Yong-Eun; Min, Sung-Wook; Im, Seongil; Choi, Hyoung Joon; Lim, Seulky; Shin, Hyunjung; Koo, Sang Man; Sung, Myung Mo


    Large-area graphene films produced by means of chemical vapor deposition (CVD) are polycrystalline and thus contain numerous grain boundaries that can greatly degrade their performance and produce inhomogeneous properties. A better grain boundary engineering in CVD graphene is essential to realize the full potential of graphene in large-scale applications. Here, we report a defect-selective atomic layer deposition (ALD) for stitching grain boundaries of CVD graphene with ZnO so as to increase the connectivity between grains. In the present ALD process, ZnO with a hexagonal wurtzite structure was selectively grown mainly on the defect-rich grain boundaries to produce ZnO-stitched CVD graphene with well-connected grains. For the CVD graphene film after ZnO stitching, the inter-grain mobility is notably improved with only a little change in the free carrier density. We also demonstrate how ZnO-stitched CVD graphene can be successfully integrated into wafer-scale arrays of top-gated field-effect transistors on 4-inch Si and polymer substrates, revealing remarkable device-to-device uniformity.Large-area graphene films produced by means of chemical vapor deposition (CVD) are polycrystalline and thus contain numerous grain boundaries that can greatly degrade their performance and produce inhomogeneous properties. A better grain boundary engineering in CVD graphene is essential to realize the full potential of graphene in large-scale applications. Here, we report a defect-selective atomic layer deposition (ALD) for stitching grain boundaries of CVD graphene with ZnO so as to increase the connectivity between grains. In the present ALD process, ZnO with a hexagonal wurtzite structure was selectively grown mainly on the defect-rich grain boundaries to produce ZnO-stitched CVD graphene with well-connected grains. For the CVD graphene film after ZnO stitching, the inter-grain mobility is notably improved with only a little change in the free carrier density. We also

  8. Thickness scaling of atomic-layer-deposited HfO2 films and their application to wafer-scale graphene tunnelling transistors. (United States)

    Jeong, Seong-Jun; Gu, Yeahyun; Heo, Jinseong; Yang, Jaehyun; Lee, Chang-Seok; Lee, Min-Hyun; Lee, Yunseong; Kim, Hyoungsub; Park, Seongjun; Hwang, Sungwoo


    The downscaling of the capacitance equivalent oxide thickness (CET) of a gate dielectric film with a high dielectric constant, such as atomic layer deposited (ALD) HfO2, is a fundamental challenge in achieving high-performance graphene-based transistors with a low gate leakage current. Here, we assess the application of various surface modification methods on monolayer graphene sheets grown by chemical vapour deposition to obtain a uniform and pinhole-free ALD HfO2 film with a substantially small CET at a wafer scale. The effects of various surface modifications, such as N-methyl-2-pyrrolidone treatment and introduction of sputtered ZnO and e-beam-evaporated Hf seed layers on monolayer graphene, and the subsequent HfO2 film formation under identical ALD process parameters were systematically evaluated. The nucleation layer provided by the Hf seed layer (which transforms to the HfO2 layer during ALD) resulted in the uniform and conformal deposition of the HfO2 film without damaging the graphene, which is suitable for downscaling the CET. After verifying the feasibility of scaling down the HfO2 thickness to achieve a CET of ~1.5 nm from an array of top-gated metal-oxide-graphene field-effect transistors, we fabricated graphene heterojunction tunnelling transistors with a record-low subthreshold swing value of <60 mV/dec on an 8" glass wafer.

  9. Atomic mechanism for the growth of wafer-scale single-crystal graphene: theoretical perspective and scanning tunneling microscopy investigations (United States)

    Niu, Tianchao; Zhang, Jialin; Chen, Wei


    Chemical vapor deposition (CVD) is the most promising approach for producing low-cost, high-quality, and large area graphene. Revealing the graphene growth mechanism at the atomic-scale is of great importance for realizing single crystal graphene (SCG) over wafer scale. Density functional theoretical (DFT) calculations are playing an increasingly important role in revealing the structure of the most stable carbon species, understanding the evolution processes, and disclosing the active sites. Scanning tunneling microscopy (STM) is a powerful surface characterization tool to illustrate the real space distribution and atomic structures of growth intermediates during the CVD process. Combining them together can provide valuable information to improve the atomically controlled growth of SCG. Starting from a basic concept of the substrate effect on realizing SCG, this review covers the progress made in theoretical investigations on various carbon species during graphene growth on different transition metal substrates, in the STM study of the structural intermediates on transition metal surfaces, and in synthesizing graphene nanoribbons with atomic-precise width and edge structure, ending with a perspective on the future development of 2D materials beyond graphene.

  10. Graphene and thin-film semiconductor heterojunction transistors integrated on wafer scale for low-power electronics. (United States)

    Heo, Jinseong; Byun, Kyung-Eun; Lee, Jaeho; Chung, Hyun-Jong; Jeon, Sanghun; Park, Seongjun; Hwang, Sungwoo


    Graphene heterostructures in which graphene is combined with semiconductors or other layered 2D materials are of considerable interest, as a new class of electronic devices has been realized. Here we propose a technology platform based on graphene-thin-film-semiconductor-metal (GSM) junctions, which can be applied to large-scale and power-efficient electronics compatible with a variety of substrates. We demonstrate wafer-scale integration of vertical field-effect transistors (VFETs) based on graphene-In-Ga-Zn-O (IGZO)-metal asymmetric junctions on a transparent 150 × 150 mm(2) glass. In this system, a triangular energy barrier between the graphene and metal is designed by selecting a metal with a proper work function. We obtain a maximum current on/off ratio (Ion/Ioff) up to 10(6) with an average of 3010 over 2000 devices under ambient conditions. For low-power logic applications, an inverter that combines complementary n-type (IGZO) and p-type (Ge) devices is demonstrated to operate at a bias of only 0.5 V.

  11. Integration of hexagonal boron nitride with quasi-freestanding epitaxial graphene: toward wafer-scale, high-performance devices. (United States)

    Bresnehan, Michael S; Hollander, Matthew J; Wetherington, Maxwell; LaBella, Michael; Trumbull, Kathleen A; Cavalero, Randal; Snyder, David W; Robinson, Joshua A


    Hexagonal boron nitride (h-BN) is a promising dielectric material for graphene-based electronic devices. Here we investigate the potential of h-BN gate dielectrics, grown by chemical vapor deposition (CVD), for integration with quasi-freestanding epitaxial graphene (QFEG). We discuss the large scale growth of h-BN on copper foil via a catalytic thermal CVD process and the subsequent transfer of h-BN to a 75 mm QFEG wafer. X-ray photoelectron spectroscopy (XPS) measurements confirm the absence of h-BN/graphitic domains and indicate that the film is chemically stable throughout the transfer process, while Raman spectroscopy indicates a 42% relaxation of compressive stress following removal of the copper substrate and subsequent transfer of h-BN to QFEG. Despite stress-induced wrinkling observed in the films, Hall effect measurements show little degradation (Graphene transistors utilizing h-BN gates exhibit peak intrinsic cutoff frequencies >30 GHz (2.4× that of HfO(2)-based devices).

  12. Wafer scale fabrication of carbon nanotube thin film transistors with high yield

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Boyuan; Liang, Xuelei, E-mail:, E-mail:; Yan, Qiuping; Zhang, Han; Xia, Jiye; Dong, Guodong; Peng, Lianmao [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China); Xie, Sishen, E-mail:, E-mail: [Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing 100871 (China); Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)


    Carbon nanotube thin film transistors (CNT-TFTs) are promising candidates for future high performance and low cost macro-electronics. However, most of the reported CNT-TFTs are fabricated in small quantities on a relatively small size substrate. The yield of large scale fabrication and the performance uniformity of devices on large size substrates should be improved before the CNT-TFTs reach real products. In this paper, 25 200 devices, with various geometries (channel width and channel length), were fabricated on 4-in. size ridged and flexible substrates. Almost 100% device yield were obtained on a rigid substrate with high out-put current (>8 μA/μm), high on/off current ratio (>10{sup 5}), and high mobility (>30 cm{sup 2}/V·s). More importantly, uniform performance in 4-in. area was achieved, and the fabrication process can be scaled up. The results give us more confidence for the real application of the CNT-TFT technology in the near future.

  13. Wafer Scale Distributed Radio (United States)


    Rload LLg *Lg*Lg*g*Lg*g*L CWk*Ck*Wk*k*Ck*k*W Ibiask*Ibiask*k*Ibias Figure 3.11: Lumped element model of a distributed amplifier. To facilitate the design...5.26) , where Z0 ≈ √ B C . By computing γ with a real part into the voltage equation , Fig. 5.7 is generated and describes the skew related to the clock... equation , we can derive: ∆ flock = f0 2Q Ain j A (5.34) with Ain j and A, the relative amplitude of the injecting signal and the oscillator signal, both

  14. Si nanowire directly grown on a liquid metal substrate—towards wafer scale transferable nanowire arrays with improved visible-light sterilization (United States)

    Wang, Hui; Wang, Jian-Tao; Ou, Xue-Mei; Lee, Chun-Sing; Zhang, Xiao-Hong


    Integrating vertically aligned nanowires (NWs) on a functional substrate is important for the application of NWs in wafer scale assemblies and functional devices. However, vertically aligned NWs via the current epitaxial growth route can only be prepared on crystalline wafers. A convenient method is thus presented to overcome NW substrate limitations. Liquid metal is proposed to serve as a substrate for the initial growth of vertically aligned NWs. NWs could then be harvested from the growth substrate and integrated with functional substrates. Fabricated vertically aligned silicon NWs (SiNWs) were grown on molten Sn and then integrated into a flexible transparent poly(dimethylsiloxane) film to obtain a SiNW/functional substrate device. The device showed enhanced visible-light absorption ability and refreshable visible-light bactericidal activities with a bacterial reduction rate of close to 100%, indicating that growth with molten metal as a substrate could be a promising approach for extending the function and application of NWs.

  15. Modeling electrodeposition for LIGA microdevice fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, S.K.; Nilson, R.H.; Bradshaw, R.W. [and others


    To better understand and to help optimize the electroforming portion of the LIGA process, we have developed one and two-dimensional numerical models describing electrode-position of metal into high aspect-ratio molds. The one-dimensional model addresses dissociation, diffusion, electromigration, and deposition of multiple ion species. The two-dimensional model is limited to a single species, but includes transport induced by forced flow of electrolyte outside the mold and by buoyancy associated with metal ion depletion within the mold. To guide model development and to validate these models, we have also conducted a series of laboratory experiments using a sulfamate bath to deposit nickel in cylindrical molds having aspect ratios up to twenty-five. The experimental results indicate that current densities well in excess of the diffusion-limited currents may still yield metal deposits of acceptable morphology. However, the numerical models demonstrate that such large ion fluxes cannot be sustained by convection within the mold resulting from flow across the mold top. Instead, calculations suggest that the observed enhancement of transport probably results from natural convection within the molds, and that buoyancy-driven flows may be critical to metal ion transport even in micron-scale features having very large aspect ratios. Taking advantage of this enhanced ion transport may allow order-of-magnitude reductions in electroforming times for LIGA microdevice fabrication. 42 refs., 14 figs., 1 tab.

  16. Laser wafering for silicon solar.

    Energy Technology Data Exchange (ETDEWEB)

    Friedmann, Thomas Aquinas; Sweatt, William C.; Jared, Bradley Howell


    Current technology cuts solar Si wafers by a wire saw process, resulting in 50% 'kerf' loss when machining silicon from a boule or brick into a wafer. We want to develop a kerf-free laser wafering technology that promises to eliminate such wasteful wire saw processes and achieve up to a ten-fold decrease in the g/W{sub p} (grams/peak watt) polysilicon usage from the starting polysilicon material. Compared to today's technology, this will also reduce costs ({approx}20%), embodied energy, and green-house gas GHG emissions ({approx}50%). We will use short pulse laser illumination sharply focused by a solid immersion lens to produce subsurface damage in silicon such that wafers can be mechanically cleaved from a boule or brick. For this concept to succeed, we will need to develop optics, lasers, cleaving, and high throughput processing technologies capable of producing wafers with thicknesses < 50 {micro}m with high throughput (< 10 sec./wafer). Wafer thickness scaling is the 'Moore's Law' of silicon solar. Our concept will allow solar manufacturers to skip entire generations of scaling and achieve grid parity with commercial electricity rates. Yet, this idea is largely untested and a simple demonstration is needed to provide credibility for a larger scale research and development program. The purpose of this project is to lay the groundwork to demonstrate the feasibility of laser wafering. First, to design and procure on optic train suitable for producing subsurface damage in silicon with the required damage and stress profile to promote lateral cleavage of silicon. Second, to use an existing laser to produce subsurface damage in silicon, and third, to characterize the damage using scanning electron microscopy and confocal Raman spectroscopy mapping.

  17. Investigation of a Hybrid Wafer Scale Integration Technique that Mounts Discrete Integrated Circuit Die in a Silicon Substrate. (United States)


    preparation of wafers for the etching study: 1. Chemicals for Standard Clean #1: Sulphuric acid (H 2SO4) Hydrogen Peroxide (H20 2 ) Hydrofluoric Acid (HF) 2...between the die and the substrate, applying a conformal dielectric smoothing layer, and then interconnecting the circuit die using a patterned thin...continued processing. A dielectric polvimide coating is spun-on and cured. Multilevel electrical a- interconnect ions are now possible (3:845-851

  18. Versatile Wafer-Scale Technique for the Formation of Ultrasmooth and Thickness-Controlled Graphene Oxide Films Based on Very Large Flakes. (United States)

    Azevedo, Joël; Campidelli, Stéphane; He, Delong; Cornut, Renaud; Bertucchi, Michael; Sorgues, Sébastien; Benattar, Jean-Jacques; Colbeau-Justin, Christophe; Derycke, Vincent


    We present a new strategy to form thickness-adjusted and ultrasmooth films of very large and unwrinkled graphene oxide (GO) flakes through the transfer of both hemispherical and vertical water films stabilized by surfactants. With its versatility in terms of substrate type (including flexible organic substrates) and in terms of flake density (from isolated flakes to continuous and multilayer films), this wafer-scale assembly technique is adapted to a broad range of experiments involving GO and rGO (reduced graphene oxide). We illustrate its use through the evaluation of transparent rGO electrodes.

  19. UV-LIGA: From Development to Commercialization

    Directory of Open Access Journals (Sweden)

    Grégoire Genolet


    Full Text Available A major breakthrough in UV-LIGA (Lithographie, Galvanoformung and Abformung started with the use of epoxy-based EPON® SU-8 photoresist in the mid-1990s. Using this photoresist has enabled the fabrication of tall and high aspect ratio structures without the use of a very expensive synchrotron source needed to expose the photoresist layer in X-ray LIGA. SU-8 photoresist appeared to be well-suited for LIGA templates, but also as a permanent material. Based on UV-LIGA and SU-8, Mimotec SA has developed processes to manufacture mold inserts and metallic components for various market fields. From one to three-level parts, from Ni to other materials, from simple to complicated parts with integrated functionalities, UV-LIGA has established itself as a manufacturing technology of importance for prototyping, as well as for mass-fabrication. This paper reviews some of the developments that led to commercial success in this field.

  20. Wafer-scale growth of highly textured piezoelectric thin films by pulsed laser deposition for micro-scale sensors and actuators

    NARCIS (Netherlands)

    Nguyen, M. D.; Tiggelaar, R.; Aukes, Thomas; Rijnders, G.; Roelof, G.


    Piezoelectric lead-zirconate-Titanate (PZT) thin films were deposited on 4-inch (111)Pt/Ti/SiO2/Si(001) wafers using large-Area pulsed laser deposition (PLD). This study was focused on the homogeneity in film thickness, microstructure, ferroelectric and piezoelectric properties of PZT thin films.

  1. Single crystal monolayer MoS2 triangles with wafer-scale spatial uniformity by MoO3 pre-deposited chemical vapor deposition (United States)

    Cheng, Zhaofang; Xia, Minggang; Hu, Ruixue; Liang, Chunping; Liang, Gongying; Zhang, Shengli


    Two-dimensional transition metal dichalcogenides (TMDs) show a potential application in photoelectric device due to their excellent electrical and optical properties. Here, we report that the MoO3 pre-deposited chemical vapor deposition (CVD) is used to synthesize single crystal monolayer MoS2 triangles on 4 in. wafer. We found that the wafer-scale uniformity of MoS2 can be greatly improved by regularly depositing MoO3 particles on substrate before CVD growth. Therefore, a piece of cleanroom wiper was used as a template for implementing precise control of MoO3 pre-deposition. We found that the optimal deposition size of MoO3 particles and the distance between MoO3 particles are about 15 μm and 0.9 mm, respectively. Both microscopic and spectroscopic characterization results demonstrate that the as-grown MoS2 is highly uniform in space distribution and crystal structure. The electronic performance of MoS2 synthesized by our method is comparable to or even slightly better than those in common CVD samples. The role of MoO3 pre-deposition is not only to effectively control the MoS2 nucleation density but also to overcome poor diffusion of MoO3 source. Our method is expected to accelerate the industrial synthesis of the atomically thin TMD materials.

  2. Wafer-scale epitaxial lift-off of optoelectronic grade GaN from a GaN substrate using a sacrificial ZnO interlayer (United States)

    Rajan, Akhil; Rogers, David J.; Ton-That, Cuong; Zhu, Liangchen; Phillips, Matthew R.; Sundaram, Suresh; Gautier, Simon; Moudakir, Tarik; El-Gmili, Youssef; Ougazzaden, Abdallah; Sandana, Vinod E.; Teherani, Ferechteh H.; Bove, Philippe; Prior, Kevin A.; Djebbour, Zakaria; McClintock, Ryan; Razeghi, Manijeh


    Full 2 inch GaN epilayers were lifted off GaN and c-sapphire substrates by preferential chemical dissolution of sacrificial ZnO underlayers. Modification of the standard epitaxial lift-off (ELO) process by supporting the wax host with a glass substrate proved key in enabling full wafer scale-up. Scanning electron microscopy and x-ray diffraction confirmed that intact epitaxial GaN had been transferred to the glass host. Depth-resolved cathodoluminescence (CL) analysis of the bottom surface of the lifted-off GaN layer revealed strong near-band-edge (3.33 eV) emission indicating a superior optical quality for the GaN which was lifted off the GaN substrate. This modified ELO approach demonstrates that previous theories proposing that wax host curling was necessary to keep the ELO etch channel open do not apply to the GaN/ZnO system. The unprecedented full wafer transfer of epitaxial GaN to an alternative support by ELO offers the perspective of accelerating industrial adoption of the expensive GaN substrate through cost-reducing recycling.

  3. Wafer-Scale Synthesized MoS2/Porous Silicon Nanostructures for Efficient and Selective Ethanol Sensing at Room Temperature. (United States)

    Dwivedi, Priyanka; Das, Samaresh; Dhanekar, Saakshi


    This paper presents the performance of a highly selective ethanol sensor based on MoS2-functionalized porous silicon (PSi). The uniqueness of the sensor includes its method of fabrication, wafer scalability, affinity for ethanol, and high sensitivity. MoS2 nanoflakes (NFs) were synthesized by sulfurization of oxidized radio-frequency (RF)-sputtered Mo thin films. The MoS2 NFs synthesis technique is superior in comparison to other methods, because it is chip-scalable and low in cost. Interdigitated electrodes (IDEs) were used to record resistive measurements from MoS2/PSi sensors in the presence of volatile organic compound (VOC) and moisture at room temperature. With the effect of MoS2 on PSi, an enhancement in sensitivity and a selective response for ethanol were observed, with a minimum detection limit of 1 ppm. The ethanol sensitivity was found to increase by a factor of 5, in comparison to the single-layer counterpart levels. This impressive response is explained on the basis of an analytical resistive model, the band gap of MoS2/PSi/Si, the interface formed between MoS2 and PSi, and the chemical interaction of the vapor molecules and the surface. This two-dimensional (2D) composite material with PSi paves the way for efficient, highly responsive, and stable sensors.

  4. Wafer-scaled monolayer WO3 windows ultra-sensitive, extremely-fast and stable UV-A photodetection (United States)

    Hai, Zhenyin; Akbari, Mohammad Karbalaei; Xue, Chenyang; Xu, Hongyan; Hyde, Lachlan; Zhuiykov, Serge


    The monolayer WO3-based UV-A photodetectors, fabricated by atomic layer deposition (ALD) technique at the large area of SiO2/Si wafer, have demonstrated vastly improved functional capabilities: extremely fast response time of less than 40 μs and photoresponsivity reaching of ∼0.329 A W-1. Their ultrafast photoresponse time is at least 400-fold improvement over the previous reports for any other WO3-based UV photodetectors that have ever been fabricated, and significantly faster than most of other photodetectors based on two-dimensional (2D) nanomaterials reported-to-date. Moreover, their measured long-term stability exceeds more than 200 cycles without any visible degradation. The ALD-deposited WO3 monolayer has also exhibited wider bandgap of 3.53 eV and the UV-A photodetector based on it is environmentally friendly, highly reliable, with excellent reproducibility and long-term stability. Thus, the shift to mono-layered semiconductors, which possess completely new quantum-confined effects, has the greatest potential in creating a new class of nano-materials, which in return windows new functional opportunities for various opto-electronic instruments built on semiconductor monolayer and, more importantly, can result in new strategy for fabrication highly-flexible, inexpensive and extremely-sensitive devices. This strategy also opens up the great opportunities for industrialization and commercialization of the photodetectors and other optoelectronic devices based on monolayer or few-layered 2D nanomaterials.

  5. Laparoscopic decortication of hilar renal cysts using LigaSure. (United States)

    Erdem, Mehmet Remzi; Tepeler, Abdulkadir; Gunes, Mustafa; Sılay, Mesrur Selcuk; Akman, Tolga; Akcay, Muzaffer; Armagan, Abdullah; Onol, Sinasi Yavuz


    In this study, we evaluated the safety and efficacy of using the LigaSure sealing system (Valleylab, Boulder, Colorado) for laparoscopic decortication of symptomatic hilar renal cysts. Seventeen patients underwent laparoscopic decortication of hilar renal cysts with the LigaSure system. Our study included only symptomatic, Bosniak type 1, simple and symptomatic renal cysts. The operative route, transperitoneal or retroperitoneal, was planned according to the location confirmed by computed tomography. The patients' symptoms were preoperatively and postoperatively evaluated by the Wong-Baker visual pain scale. Operative measures and radiologic outcomes were prospectively evaluated. The mean age of the patients was 56.4 years, and the mean follow-up period was 12.5 months. Preoperative computed tomography showed only a single cyst in 15 patients (88.2%) and showed two separate cysts in 2 cases (11.8%). The cysts were located in the perihilar region close to the vascular structure in all patients. A transperitoneal approach was used in 9 patients, and a retroperitoneal approach was used in 8 patients. The mean operative time and hospitalization time were 56.4 minutes and 1.2 days, respectively. Minor complications were observed in 3 patients. Symptomatic and radiologic success rates of 94.2% and 100%, respectively, were achieved. Laparoscopic decortication of symptomatic hilar renal cysts--first reported in the literature in this study--using the LigaSure sealing system is feasible, effective, and safe, even if the cyst is located in the perihilar area.

  6. X-ray performance of a wafer-scale CMOS flat panel imager for applications in medical imaging and nondestructive testing

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Bo Kyung, E-mail: [Advanced Medical Device Research Center, Korea Electrotechnology Research Institute, Ansan (Korea, Republic of); Jeon, Seongchae [Advanced Medical Device Research Center, Korea Electrotechnology Research Institute, Ansan (Korea, Republic of); Seo, Chang-Woo [Department of Radiological Science, Yonsei University, Gangwon-do 220-710 (Korea, Republic of)


    This paper presents a wafer-scale complementary metal-oxide semiconductor (CMOS)-based X-ray flat panel detector for medical imaging and nondestructive testing applications. In this study, our proposed X-ray CMOS flat panel imager has been fabricated by using a 0.35 µm 1-poly/4-metal CMOS process. The pixel size is 100 µm×100 µm and the pixel array format is 1200×1200 pixels, which provide a field-of-view (FOV) of 120mm×120 mm. The 14.3-bit extended counting analog-to digital converter (ADC) with built-in binning mode was used to reduce the area and simultaneously improve the image resolution. The different screens such as thallium-doped CsI (CsI:Tl) and terbium gadolinium oxysulfide (Gd{sub 2}O{sub 2}S:Tb) scintillators were used as conversion materials for X-rays to visible light photons. The X-ray imaging performance such as X-ray sensitivity as a function of X-ray exposure dose, spatial resolution, image lag and X-ray images of various objects were measured under practical medical and industrial application conditions. This paper results demonstrate that our prototype CMOS-based X-ray flat panel imager has the significant potential for medical imaging and non-destructive testing (NDT) applications with high-resolution and high speed rate.

  7. On the complexity of Wafer-to-Wafer Integration


    Duvillié, Guillerme; Bougeret, Marin; Boudet, Vincent; Dokka, Trivikram; Giroudeau, Rodolphe


    In this paper we consider the Wafer-to-Wafer Integration problem. A wafer can be seen as a pp-dimensional binary vector. The input of this problem is described by mm multisets (called “lots”), where each multiset contains nn wafers. The output of the problem is a set of nn disjoint stacks, where a stack is a set of mm wafers (one wafer from each lot). To each stack we associate a pp-dimensional binary vector corresponding to the bit-wise AND operation of the wafers of the stack. The objective...

  8. Wafer-scale single-crystal perovskite patterned thin films based on geometrically-confined lateral crystal growth (United States)

    Lee, Lynn; Baek, Jangmi; Park, Kyung Sun; Lee, Yong-Eunkoo; Shrestha, Nabeen K.; Sung, Myung M.


    We report a facile roll-printing method, geometrically confined lateral crystal growth, for the fabrication of large-scale, single-crystal CH3NH3PbI3 perovskite thin films. Geometrically confined lateral crystal growth is based on transfer of a perovskite ink solution via a patterned rolling mould to a heated substrate, where the solution crystallizes instantly with the immediate evaporation of the solvent. The striking feature of this method is that the instant crystallization of the feeding solution under geometrical confinement leads to the unidirectional lateral growth of single-crystal perovskites. Here, we fabricated single-crystal perovskites in the form of a patterned thin film (3 × 3 inch) with a high carrier mobility of 45.64 cm2 V-1 s-1. We also used these single-crystal perovskite thin films to construct solar cells with a lateral configuration. Their active-area power conversion efficiency shows a highest value of 4.83%, which exceeds the literature efficiency values of lateral perovskite solar cells.

  9. Wafer-scale single-crystal perovskite patterned thin films based on geometrically-confined lateral crystal growth (United States)

    Lee, Lynn; Baek, Jangmi; Park, Kyung Sun; Lee, Yong-EunKoo; Shrestha, Nabeen K.; Sung, Myung M.


    We report a facile roll-printing method, geometrically confined lateral crystal growth, for the fabrication of large-scale, single-crystal CH3NH3PbI3 perovskite thin films. Geometrically confined lateral crystal growth is based on transfer of a perovskite ink solution via a patterned rolling mould to a heated substrate, where the solution crystallizes instantly with the immediate evaporation of the solvent. The striking feature of this method is that the instant crystallization of the feeding solution under geometrical confinement leads to the unidirectional lateral growth of single-crystal perovskites. Here, we fabricated single-crystal perovskites in the form of a patterned thin film (3 × 3 inch) with a high carrier mobility of 45.64 cm2 V−1 s−1. We also used these single-crystal perovskite thin films to construct solar cells with a lateral configuration. Their active-area power conversion efficiency shows a highest value of 4.83%, which exceeds the literature efficiency values of lateral perovskite solar cells. PMID:28691697

  10. Wafer characteristics via reflectometry (United States)

    Sopori, Bhushan L.


    Various exemplary methods (800, 900, 1000, 1100) are directed to determining wafer thickness and/or wafer surface characteristics. An exemplary method (900) includes measuring reflectance of a wafer and comparing the measured reflectance to a calculated reflectance or a reflectance stored in a database. Another exemplary method (800) includes positioning a wafer on a reflecting support to extend a reflectance range. An exemplary device (200) has an input (210), analysis modules (222-228) and optionally a database (230). Various exemplary reflectometer chambers (1300, 1400) include radiation sources positioned at a first altitudinal angle (1308, 1408) and at a second altitudinal angle (1312, 1412). An exemplary method includes selecting radiation sources positioned at various altitudinal angles. An exemplary element (1650, 1850) includes a first aperture (1654, 1854) and a second aperture (1658, 1858) that can transmit reflected radiation to a fiber and an imager, respectfully.

  11. Stable wafer-carrier system

    Energy Technology Data Exchange (ETDEWEB)

    Rozenzon, Yan; Trujillo, Robert T; Beese, Steven C


    One embodiment of the present invention provides a wafer-carrier system used in a deposition chamber for carrying wafers. The wafer-carrier system includes a base susceptor and a top susceptor nested inside the base susceptor with its wafer-mounting side facing the base susceptor's wafer-mounting side, thereby forming a substantially enclosed narrow channel. The base susceptor provides an upward support to the top susceptor.

  12. Wafer screening device and methods for wafer screening (United States)

    Sopori, Bhushan; Rupnowski, Przemyslaw


    Wafer breakage is a serious problem in the photovoltaic industry because a large fraction of wafers (between 5 and 10%) break during solar cell/module fabrication. The major cause of this excessive wafer breakage is that these wafers have residual microcracks--microcracks that were not completely etched. Additional propensity for breakage is caused by texture etching and incomplete edge grinding. To eliminate the cost of processing the wafers that break, it is best to remove them prior to cell fabrication. Some attempts have been made to develop optical techniques to detect microcracks. Unfortunately, it is very difficult to detect microcracks that are embedded within the roughness/texture of the wafers. Furthermore, even if such detection is successful, it is not straightforward to relate them to wafer breakage. We believe that the best way to isolate the wafers with fatal microcracks is to apply a stress to wafers--a stress that mimics the highest stress during cell/module processing. If a wafer survives this stress, it has a high probability of surviving without breakage during cell/module fabrication. Based on this, we have developed a high throughput, noncontact method for applying a predetermined stress to a wafer. The wafers are carried on a belt through a chamber that illuminates the wafer with an intense light of a predetermined intensity distribution that can be varied by changing the power to the light source. As the wafers move under the light source, each wafer undergoes a dynamic temperature profile that produces a preset elastic stress. If this stress exceeds the wafer strength, the wafer will break. The broken wafers are separated early, eliminating cost of processing into cell/module. We will describe details of the system and show comparison of breakage statistics with the breakage on a production line.

  13. Simulation and experimental determination of the macro-scale layer thickness distribution of electrodeposited Cu-line patterns on a wafer substrate

    DEFF Research Database (Denmark)

    Pantleon, Karen; Bossche, Bart van den; Purcar, Marius


    on the patterned wafer, and layer thickness measurements by means of X-ray fluorescence (XRF) and atomic force microscopy (AFM). The simulations are based on a potential model approach taking into account electrolyte ohmic drop and electrode polarization effects, combined to a boundary element method (BEM...

  14. 1366 Direct Wafer: Demolishing the Cost Barrier for Silicon Photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Adam [1366 Technologies


    The goal of 1366 Direct Wafer™ is to drastically reduce the cost of silicon-based PV by eliminating the cost barrier imposed by sawn wafers. The key characteristics of Direct Wafer are 1) kerf-free, 156-mm standard silicon wafers 2) high throughput for very low CAPEX and rapid scale up. Together, these characteristics will allow Direct Wafer™ to become the new standard for silicon PV wafers and will enable terawatt-scale PV – a prospect that may not be possible with sawn wafers. Our single, high-throughput step will replace the expensive and rate-limiting process steps of ingot casting and sawing, thereby enabling drastically lower wafer cost. This High-Impact PV Supply Chain project addressed the challenges of scaling Direct Wafer technology for cost-effective, high-throughput production of commercially viable 156 mm wafers. The Direct Wafer process is inherently simple and offers the potential for very low production cost, but to realize this, it is necessary to demonstrate production of wafers at high-throughput that meet customer specifications. At the start of the program, 1366 had demonstrated (with ARPA-E funding) increases in solar cell efficiency from 10% to 15.9% on small area (20cm2), scaling wafer size up to the industry standard 156mm, and demonstrated initial cell efficiency on larger wafers of 13.5%. During this program, the throughput of the Direct Wafer furnace was increased by more than 10X, simultaneous with quality improvements to meet early customer specifications. Dedicated equipment for laser trimming of wafers and measurement methods were developed to feedback key quality metrics to improve the process and equipment. Subsequent operations served both to determine key operating metrics affecting cost, as well as generating sample product that was used for developing downstream processing including texture and interaction with standard cell processing. Dramatic price drops for silicon wafers raised the bar significantly, but the

  15. Handbook of wafer bonding

    CERN Document Server

    Ramm, Peter; Taklo, Maaike M V


    Written by an author and editor team from microsystems companies and industry-near research organizations, this handbook and reference presents dependable, first-hand information on bonding technologies.In the first part, researchers from companies and institutions around the world discuss the most reliable and reproducible technologies for the production of bonded wafers. The second part is devoted to current and emerging applications, including microresonators, biosensors and precise measuring devices.

  16. Wafer-scale crack-free AlGaN on GaN through two-step selective-area growth for optically pumped stimulated emission (United States)

    Ko, Young-Ho; Bae, Sung-Bum; Kim, Sung-Bock; Kim, Dong Churl; Leem, Young Ahn; Cho, Yong-Hoon; Nam, Eun-Soo


    Crack-free AlGaN template has been successfully grown over entire 2-in. wafer by using 2-step selective-area growth (SAG). The GaN truncated structure was obtained by vertical growth mode with low growth temperature. AlGaN of second step was grown under lateral growth mode. Low pressure enhanced the relative ratio of lateral to vertical growth rate as well as absolute overall growth rate. High V/III ratio was favorable for lateral growth mode. Crack-free planar AlGaN was obtained under low pressure of 30 Torr and high V/III ratio of 4400. The AlGaN was crack-free over entire 2-in. wafer and had quite uniform Al-mole fraction. The dislocation density of the AlGaN with 20% Al-composition was as low as ~7.6×108 /cm2, measured by cathodoluminescence. GaN/AlGaN multi-quantum well (MQW) with cladding and waveguide layers were grown on the crack-free AlGaN template with low dislocation density. It was confirmed that the MQW on the AlGaN template emitted the stimulated emission at 355.5 nm through optical pumping experiment. The AlGaN obtained by 2-step SAG would provide high crystal quality for highly-efficient optoelectronic devices as well as the ultraviolet laser diode.

  17. Rules-based correction strategies setup on sub-micrometer line and space patterns for 200mm wafer scale SmartNIL process within an integration process flow (United States)

    Teyssedre, H.; Landis, S.; Brianceau, P.; Mayr, M.; Thanner, C.; Laure, M.; Zorbach, W.; Eibelhuber, M.; Pain, L.; Chouiki, M.; Wimplinger, M.


    In this paper the rules-based correction strategies for the nanoimprint lithography (NIL) technology are addressed using complete Scanning Electron Microscopy (SEM) characterizations. Performed onto 200 mm wafers imprinted with the HERCULES NIL equipment platform, Critical Dimension (CD) uniformity analyses are used to measure the evolution of lines and spaces features dimensions from the master to 50 consecutive imprints. The work brings focus on sub micrometer resolution features with duty cycles from 3 to 7. The silicon masters were manufactured with 193 optical lithography and dry etching and were fully characterized prior to the imprint process. Repeatability tests were performed over 50 wafers for two different processes to collect statistical and comparative data. The data revealed that the CD evolutions can be modelled by quadratic functions with respect to the number of imprints and feature dimension (CD and pitch) on the master. These models are used to establish the rules-based corrections for lines arrays in the scope of nanoimprint master manufacturing, and it opens the discussion on the process monitoring through metrology for the nanoimprint soft stamp technologies.

  18. Micro-grippers for assembly of LIGA parts

    Energy Technology Data Exchange (ETDEWEB)

    Feddema, J.; Polosky, M.; Christenson, T.; Spletzer, B.; Simon, R.


    This paper describes ongoing testing of two microgrippers for assembly of LIGA (Lithographie Galvanoformung Abformung) parts. The goal is to place 100 micron outside diameter (OD) LIGA gears with a 50 micron inner diameter hole onto pins ranging from 35 to 49 microns. The first micro gripper is a vacuum gripper made of a 100 micron OD stainless steel tube. The second micro gripper is a set of tweezers fabricated using the LIGA process. Nickel, Permalloy, and copper materials are tested. The tweezers are actuated by a collet mechanism which is closed by a DC linear motor.

  19. Wafer-scale controlled exfoliation of metal organic vapor phase epitaxy grown InGaN/GaN multi quantum well structures using low-tack two-dimensional layered h-BN

    Energy Technology Data Exchange (ETDEWEB)

    Ayari, Taha; Li, Xin; Voss, Paul L.; Ougazzaden, Abdallah, E-mail: [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Georgia Tech Lorraine, UMI 2958, Georgia Tech-CNRS, 57070 Metz (France); Sundaram, Suresh; El Gmili, Youssef [Georgia Tech Lorraine, UMI 2958, Georgia Tech-CNRS, 57070 Metz (France); Salvestrini, Jean Paul [Georgia Tech Lorraine, UMI 2958, Georgia Tech-CNRS, 57070 Metz (France); Université de Lorraine, LMOPS, EA 4423, 57070 Metz (France)


    Recent advances in epitaxial growth have led to the growth of III-nitride devices on 2D layered h-BN. This advance has the potential for wafer-scale transfer to arbitrary substrates, which could improve the thermal management and would allow III-N devices to be used more flexibly in a broader range of applications. We report wafer scale exfoliation of a metal organic vapor phase epitaxy grown InGaN/GaN Multi Quantum Well (MQW) structure from a 5 nm thick h-BN layer that was grown on a 2-inch sapphire substrate. The weak van der Waals bonds between h-BN atomic layers break easily, allowing the MQW structure to be mechanically lifted off from the sapphire substrate using a commercial adhesive tape. This results in the surface roughness of only 1.14 nm on the separated surface. Structural characterizations performed before and after the lift-off confirm the conservation of structural properties after lift-off. Cathodoluminescence at 454 nm was present before lift-off and 458 nm was present after. Electroluminescence near 450 nm from the lifted-off structure has also been observed. These results show that the high crystalline quality ultrathin h-BN serves as an effective sacrificial layer—it maintains performance, while also reducing the GaN buffer thickness and temperature ramps as compared to a conventional two-step growth method. These results support the use of h-BN as a low-tack sacrificial underlying layer for GaN-based device structures and demonstrate the feasibility of large area lift-off and transfer to any template, which is important for industrial scale production.

  20. Wafer-Level Vacuum Packaging of Smart Sensors

    Directory of Open Access Journals (Sweden)

    Allan Hilton


    Full Text Available The reach and impact of the Internet of Things will depend on the availability of low-cost, smart sensors—“low cost” for ubiquitous presence, and “smart” for connectivity and autonomy. By using wafer-level processes not only for the smart sensor fabrication and integration, but also for packaging, we can further greatly reduce the cost of sensor components and systems as well as further decrease their size and weight. This paper reviews the state-of-the-art in the wafer-level vacuum packaging technology of smart sensors. We describe the processes needed to create the wafer-scale vacuum microchambers, focusing on approaches that involve metal seals and that are compatible with the thermal budget of complementary metal-oxide semiconductor (CMOS integrated circuits. We review choices of seal materials and structures that are available to a device designer, and present techniques used for the fabrication of metal seals on device and window wafers. We also analyze the deposition and activation of thin film getters needed to maintain vacuum in the ultra-small chambers, and the wafer-to-wafer bonding processes that form the hermetic seal. We discuss inherent trade-offs and challenges of each seal material set and the corresponding bonding processes. Finally, we identify areas for further research that could help broaden implementations of the wafer-level vacuum packaging technology.

  1. O forjamento de ligas de alumínio : um estudo para a liga ABNT 6061


    Rogério Alves Oliveira


    Este trabalho pretende, na visão de novas tecnologias, discutir o processo de forjamento das ligas de alumínio (ABNT 6061), buscando propor uma metodologia baseada na ciência da engenharia. Deseja-se minimizar os procedimentos de tentativa e erro no desenvolvimento de processos de conformação. Para tanto, novas tecnologias disponíveis atualmente, tais como o Projeto Assistido por Computador (CAD), a Fabricação Assistida por Computador (CAM) e a Simulação do Processo (CAE) são empregadas. Resu...

  2. Wafer bonding applications and technology

    CERN Document Server

    Gösele, Ulrich


    During the past decade direct wafer bonding has developed into a mature materials integration technology. This book presents state-of-the-art reviews of the most important applications of wafer bonding written by experts from industry and academia. The topics include bonding-based fabrication methods of silicon-on-insulator, photonic crystals, VCSELs, SiGe-based FETs, MEMS together with hybrid integration and laser lift-off. The non-specialist will learn about the basics of wafer bonding and its various application areas, while the researcher in the field will find up-to-date information about this fast-moving area, including relevant patent information.

  3. Wafer-scaled monolayer WO{sub 3} windows ultra-sensitive, extremely-fast and stable UV-A photodetection

    Energy Technology Data Exchange (ETDEWEB)

    Hai, Zhenyin; Akbari, Mohammad Karbalaei [Ghent University Global Campus, Department of Applied Analytical & Physical Chemistry, Faculty of Bioscience Engineering, 119 Songdomunhwa-ro, Yeonsu-gu, Incheon 21985 (Korea, Republic of); Xue, Chenyang [Key Laboratory of Instrumentation Science and Dynamic Measurement of Ministry of Education, North University of China, Taiyuan, Shanxi 030051 (China); Xu, Hongyan [School of Materials Science and Engineering, North University of China, Taiyuan, Shanxi 030051 (China); Hyde, Lachlan [Melbourne Centre for Nanofabrication, Clayton, Victoria 3168 (Australia); Zhuiykov, Serge, E-mail: [Ghent University Global Campus, Department of Applied Analytical & Physical Chemistry, Faculty of Bioscience Engineering, 119 Songdomunhwa-ro, Yeonsu-gu, Incheon 21985 (Korea, Republic of)


    Highlights: • Monolayer WO{sub 3}-based photodetectors were fabricated for the first time. • The device has ultrafast response time of ∼40 μs and responsivity of ∼0.329 A W{sup −1}. • The response time is 400-fold improvement over any other WO{sub 3} UV photodetectors. • The device has better characteristics than many 2D materials-based photodetectors. • This proposed strategy has great potential for commercialization of photodetectors. - Abstract: The monolayer WO{sub 3}-based UV-A photodetectors, fabricated by atomic layer deposition (ALD) technique at the large area of SiO{sub 2}/Si wafer, have demonstrated vastly improved functional capabilities: extremely fast response time of less than 40 μs and photoresponsivity reaching of ∼0.329 A W{sup −1}. Their ultrafast photoresponse time is at least 400-fold improvement over the previous reports for any other WO{sub 3}-based UV photodetectors that have ever been fabricated, and significantly faster than most of other photodetectors based on two-dimensional (2D) nanomaterials reported-to-date. Moreover, their measured long-term stability exceeds more than 200 cycles without any visible degradation. The ALD-deposited WO{sub 3} monolayer has also exhibited wider bandgap of 3.53 eV and the UV-A photodetector based on it is environmentally friendly, highly reliable, with excellent reproducibility and long-term stability. Thus, the shift to mono-layered semiconductors, which possess completely new quantum-confined effects, has the greatest potential in creating a new class of nano-materials, which in return windows new functional opportunities for various opto-electronic instruments built on semiconductor monolayer and, more importantly, can result in new strategy for fabrication highly-flexible, inexpensive and extremely-sensitive devices. This strategy also opens up the great opportunities for industrialization and commercialization of the photodetectors and other optoelectronic devices based on

  4. Solution structure of leptospiral LigA4 Big domain

    Energy Technology Data Exchange (ETDEWEB)

    Mei, Song; Zhang, Jiahai [Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhang, Xuecheng [School of Life Sciences, Anhui University, Hefei, Anhui 230039 (China); Tu, Xiaoming, E-mail: [Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China)


    Pathogenic Leptospiraspecies express immunoglobulin-like proteins which serve as adhesins to bind to the extracellular matrices of host cells. Leptospiral immunoglobulin-like protein A (LigA), a surface exposed protein containing tandem repeats of bacterial immunoglobulin-like (Big) domains, has been proved to be involved in the interaction of pathogenic Leptospira with mammalian host. In this study, the solution structure of the fourth Big domain of LigA (LigA4 Big domain) from Leptospira interrogans was solved by nuclear magnetic resonance (NMR). The structure of LigA4 Big domain displays a similar bacterial immunoglobulin-like fold compared with other Big domains, implying some common structural aspects of Big domain family. On the other hand, it displays some structural characteristics significantly different from classic Ig-like domain. Furthermore, Stains-all assay and NMR chemical shift perturbation revealed the Ca{sup 2+} binding property of LigA4 Big domain. - Highlights: • Determining the solution structure of a bacterial immunoglobulin-like domain from a surface protein of Leptospira. • The solution structure shows some structural characteristics significantly different from the classic Ig-like domains. • A potential Ca{sup 2+}-binding site was identified by strains-all and NMR chemical shift perturbation.

  5. Breakthrough UV LIGA Microfabrication of Sub-mm and THz Circuits (United States)


    LIGA process, a mask was generated with scaled versions of both EIK ladders and folded waveguide TWT structures at atmospheric window frequencies of...ratios greater than 10:1. Fig. 3 shows the folded waveguide TWT in SU-8 for the same frequency range. The 1.35 THz and 1.5 THz versions were...due to excessive vertical aspect ratio. Figure 3. Folded Waveguide TWT circuit molds made from SU-8 at (a) 0.85 THz, (b) 1.03 THz, (c) 1.35 THz

  6. Bondability of processed glass wafers

    NARCIS (Netherlands)

    Pandraud, G.; Gui, C.; Lambeck, Paul; Pigeon, F.; Parriaux, O.; Gorecki, Christophe


    The mechanism of direct bonding at room temperature has been attributed to the short range inter-molecular and inter-atomic attraction forces, such as Van der Waals forces. Consequently, the wafer surface smoothness becomes one of the most critical parameters in this process. High surface roughness

  7. Wafer of Intel Pentium 4 Prescott Chips

    CERN Multimedia

    Silicon wafer with hundreds of Penryn cores (microprocessor). There are around four times as many Prescott chips can be made per wafer than with the previous generation of Northwood-core Pentium 4 processors. It is faster and cheaper.

  8. Control wafer bow of InGaP on 200 mm Si by strain engineering (United States)

    Wang, Bing; Bao, Shuyu; Made, Riko I.; Lee, Kwang Hong; Wang, Cong; Eng Kian Lee, Kenneth; Fitzgerald, Eugene A.; Michel, Jurgen


    When epitaxially growing III–V compound semiconductors on Si substrates the mismatch of coefficients of thermal expansion (CTEs) between III–V and Si causes stress and wafer bow. The wafer bow is deleterious for some wafer-scale processing especially when the wafer size is large. Strain engineering was applied in the epitaxy of InGaP films on 200 mm silicon wafers having high quality germanium buffers. By applying compressive strain in the InGaP films to compensate the tensile strain induced by CTE mismatch, wafer bow was decreased from about 100 μm to less than 50 μm. X-ray diffraction studies show a clear trend between the decrease of wafer bow and the compensation of CTE mismatch induced tensile strain in the InGaP layers. In addition, the anisotropic strain relaxation in InGaP films resulted in anisotropic wafer bow along two perpendicular (110) directions. Etch pit density and plane-view transmission electron microscopy characterizations indicate that threading dislocation densities did not change significantly due to the lattice-mismatch applied in the InGaP films. This study shows that strain engineering is an effective method to control wafer bow when growing III–V semiconductors on large size Si substrates.

  9. Wafering economies for industrialization from a wafer manufacturer's viewpoint (United States)

    Rosenfield, T. P.; Fuerst, F. P.


    The key technical limitations which inhibit the lowering of value-added costs for state-of-the-art wafering techniques are assessed. From the best experimental results to date, a projection was made to identify those parts of each system which need to be developed in order to meet or improve upon the value-added cost reduction necessary for $0.70/Wp photovoltaics modules.

  10. WDDM - a wafer scale data driven multiprocessor

    Energy Technology Data Exchange (ETDEWEB)

    Shirazi, B.


    It has been shown that the existing von-Neumann design machines fail to meet the requirements of the real time scientific and 5th generation applications. A computer organization, such as data driven architecture, which embeds parallelism in its definition and underlying design is needed to satisfy such requirements. In this project, a new data driven multiprocessor is introduced which: (i) eliminates some of the problems of the existing data driven systems; (ii) takes advantage of state of the art technology; and (iii) takes advantage of state-of the art technology; and (iii) achieves parallelism at the data, instruction, and program block levels. This system consists of n processing modules, a host module, and a data structure module, connected via a double star network with the host and the data structure modules in the center of the stars. Processing modules are capable of the simultaneous execution of the independent program blocks in data driven fashion. The host module is responsible for memory management tasks, while the data structure module facilitates the manipulation of the data structures.

  11. Silicon Hybrid Wafer Scale Integration Interconnect Evaluation (United States)


    Since WSI interconnection structures do not always lend themselves to an unam - biguous identification classification within the generalized class of...G.5. Measured chtaracter’ist ic ImpJedlance of St ructutre (G5 fromi Ill’ [)IQ\\ VIh (ceniter conduictor). (a) Niagnit tide. (1)) Ph1ase

  12. Laparoscopic splenectomy using LigaSure in benign hematologic diseases. (United States)

    Canda, Aras Emre; Ozsoy, Yucel; Yuksel, Safak


    Today laparoscopic splenectomy (LS) is considered the gold standard for the treatment of hematologic disorders of the spleen with the aid of advancements in laparoscopy technique and modern electrosurgical devices. LigaSure vessel sealing system permanently fuses vessels up to 7 mm in diameter by applying a precise amount of pressure and bipolar energy to the tissue. We performed 14 LSs (7 has autoimmune hemolytic anemia, 6 has idiopathic thrombocytopenic purpura, and 1 has hereditary spherocytosis) using LigaSure. The mean spleen weight was 247 g (range, 147 to 620) and the largest diameter of the spleen was 12.1 cm (range, 10 to 23). The average operative time was 84.7 minutes (range, 30 to 190) including combined laparoscopic cholecystectomy in 2 patients and transabdominal preperitoneal inguinal hernia repair in 1 patient. Conversion to open procedure was unnecessary in our series. Minor morbidity occurred in 2 patients; no perioperative hemorrhage or mortality was observed. The average postoperative hospital stay was 3.1 days (range, 2 to 8). LS is a safe and feasible procedure for patients with previous abdominal surgery; gallstones in association with hemolytic anemia can also be treated during LS. LigaSure vessel sealing system during LS is safe and cost-effective method and reduces operating time.

  13. MEMS packaging with etching and thinning of lid wafer to form lids and expose device wafer bond pads (United States)

    Chanchani, Rajen; Nordquist, Christopher; Olsson, Roy H; Peterson, Tracy C; Shul, Randy J; Ahlers, Catalina; Plut, Thomas A; Patrizi, Gary A


    In wafer-level packaging of microelectromechanical (MEMS) devices a lid wafer is bonded to a MEMS wafer in a predermined aligned relationship. Portions of the lid wafer are removed to separate the lid wafer into lid portions that respectively correspond in alignment with MEMS devices on the MEMS wafer, and to expose areas of the MEMS wafer that respectively contain sets of bond pads respectively coupled to the MEMS devices.

  14. High Speed On-Wafer Characterization Laboratory (United States)

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  15. Prevalencia de lesiones en triatletas de una liga francesa


    Galera, Olivier; Gleizes-Cervera, Sophie; Pillard, Fabien; Riviere, Daniel


    Objetivo Evaluar la prevalencia de traumatismos en triatletas y buscar los factores contribuyentes implicados. Método Se envió por correo un cuestionario anónimo sobre los casos de traumatismos durante la temporada pasada a 788 triatletas de una liga francesa. Resultados El 52,4% de los triatletas que respondieron notificaron que habían sufrido como mínimo una lesión durante la temporada pasada y el 17% varias lesiones. El 83,5% de las lesiones se produjeron durante...

  16. Enhanced adhesion for LIGA microfabrication by using a buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Bajikar, Sateesh S.; DeCarlo, Francesco; Song, Joshua J.


    The present invention is an improvement on the LIGA microfabrication process wherein a buffer layer is applied to the upper or working surface of a substrate prior to the placement of a resist onto the surface of the substrate. The buffer layer is made from an inert low-Z material (low atomic weight), a material that absorbs secondary X-rays emissions from the substrate that are generated from the substrate upon exposure to a primary X-rays source. Suitable materials for the buffer layer include polyamides and polyimide. The preferred polyimide is synthesized from pyromellitic anhydride and oxydianiline (PMDA-ODA).

  17. Enhanced adhesion for LIGA microfabrication by using a buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Bajikar, Sateesh S.; De Carlo, Francesco; Song, Joshua J.


    The present invention is an improvement on the LIGA microfabrication process wherein a buffer layer is applied to the upper or working surface of a substrate prior to the placement of a resist onto the surface of the substrate. The buffer layer is made from an inert low-Z material (low atomic weight), a material that absorbs secondary X-rays emissions from the substrate that are generated from the substrate upon exposure to a primary X-rays source. Suitable materials for the buffer layer include polyamides and polyimide. The preferred polyimide is synthesized form pyromellitic anhydride and oxydianiline (PMDA-ODA).

  18. Enhanced adhesion for LIGA microfabrication by using a buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Bajikar, Sateesh S. (San Jose, CA); De Carlo, Francesco (Darien, IL); Song, Joshua J. (Naperville, IL)


    The present invention is an improvement on the LIGA microfabrication process wherein a buffer layer is applied to the upper or working surface of a substrate prior to the placement of a resist onto the surface of the substrate. The buffer layer is made from an inert low-Z material (low atomic weight), a material that absorbs secondary X-rays emissions from the substrate that are generated from the substrate upon exposure to a primary X-rays source. Suitable materials for the buffer layer include polyamides and polyimide. The preferred polyimide is synthesized form pyromellitic anhydride and oxydianiline (PMDA-ODA).

  19. Long-term results using LigaSure™ 5 mm instrument for treatment of Zenker's diverticulum

    DEFF Research Database (Denmark)

    Andersen, Michelle Fog; Trolle, Waldemar; Anthonsen, Kristian


    to all patients. The questions dealt with complaints according to a visual analog scale (VAS) and were sent a minimum of one year after the surgery (mean time 22 months, range 12-32 month). The overall response rate was 91%. The mean age of the patients was 69 years (range 37-89 years). The patients......%) reported no symptoms at all. Our results suggest that endoscopic management of ZD with the LigaSure™ 5 mm instrument is a minimally invasive, fast and safe method with solid long-term outcome with relief of symptoms and patient satisfaction. This new operative instrument was not found inferior...

  20. Electrical Interconnections Through CMOS Wafers

    DEFF Research Database (Denmark)

    Rasmussen, Frank Engel


    Chips with integrated vias are currently the ultimate miniaturizing solution for 3D packaging of microsystems. Previously the application of vias has almost exclusively been demonstrated within MEMS technology, and only a few of these via technologies have been CMOS compatible. This thesis...... connections. A process for wafer level packaging and assembly of chips with vias is presented in this thesis. Discrete components, capacitors and resistors, are assembled on the backside of the amplifier chips by screen printing of solder paste, pick and place of components, and reflow soldering. Since...... the technology facilitates integration of discrete components directly on the surface of the chip, the need for an additional substrate is eliminated. For a single chip solution employing the presented via technology and on-chip integration of components, the total height of the package constituting a complete...

  1. Classifier combination for wafer segmentation (United States)

    Bourgeat, Pierrick T.; Meriaudeau, Fabrice


    In the last decade, the accessibility of inexpensive and powerful computers has allowed true digital holography to be used for industrial inspection. This technique allows capturing a complex image of a scene (i.e. containing magnitude and phase), and reconstructing the phase and magnitude information. Digital holograms give a new dimension to texture analysis since the topology information can be used as an additional way to extract features. This new technique can be used to extend previous work on image segmentation of patterned wafers for defect detection. This paper presents a combination of features obtained from Gabor filters on different complex images. The combination enables to cope with the intensity variations occurring during the holography and provides final results which are independent from the selected training samples.

  2. Formation and combustion characteristics of elephantgrass and energycane wafers (United States)

    Mofleh, Mohamad I.

    Elephantgrass (Pennisetum purpureum Schum.) and energycane (Saccharum Spp.) are two cane type grasses. These are tall-growing perennial bunchgrasses that produce long hardened stems and grow in the tropics and subtropics. Traditionally, they have been used for forage and, in some regions, have been randomly burned on fields or disposed of uselessly. However, these plants have high dry matter yield and, thus, are excellent candidates as energy crops. Elephantgrass and energycane have been used for direct combustion in their loose form in large-scale applications. Several problems, many of which were attributed to their low bulk density, were encountered with using the materials. Consequently, this project was initiated to investigate the formation and combustion characteristics of the two materials in the form of small compact units called wafers. A hydraulic press that applied axial stresses on the material in four different dies was used. A load cell and a displacement transducer were utilized to measure the stresses and material detection. Wafer quality was evaluated using a tumbler built according to the American Society of Agricultural Engineers standards. In addition, a small stove was built to test wafer combustion. Thermocouples were used to measure temperatures during combustion. All the data gathered was transferred to a computer using a data acquisition system. It was found that the stress-deformation and stress-density relationships of elephantgrass and energycane were of exponential nature. Compaction energy required, which was calculated from the area under the force-deformation curves, ranged from 0.1 to 0.3% of their energy content. It was also found that wafer quality (durability) was mainly a function of wafer size and its final (relaxed) density in addition to material stem-to-leaf ratio and its crude protein content. Wafers possessed poor ignition quality but once ignited, they burned satisfactorily. The results indicated that sufficient and

  3. Fabricating Capacitive Micromachined Ultrasonic Transducers with Wafer Bonding Technique




    We report the fabrication of capacitive micromachined ultrasonic transducer by wafer bonding technique. Membrane is transferred from SOI wafer to the prime wafer having silicon dioxide cavity. The thickness of cavity height depends on silicon dioxide grown on prime wafer by dry/wet oxidation. Thinning of device wafer of SOI by oxidation, controls membrane thickness. Two wafers are bonded in vacuum under optimized controlled parameters. Using this method, we can get single crystal silicon as m...

  4. LIGA-based microsystem manufacturing:the electrochemistry of through-mold depostion and material properties.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, James J. (Sandia National Laboratories, Livermore, CA); Goods, Steven Howard (Sandia National Laboratories, Livermore, CA)


    The report presented below is to appear in ''Electrochemistry at the Nanoscale'', Patrik Schmuki, Ed. Springer-Verlag, (ca. 2005). The history of the LIGA process, used for fabricating dimensional precise structures for microsystem applications, is briefly reviewed, as are the basic elements of the technology. The principal focus however, is on the unique aspects of the electrochemistry of LIGA through-mask metal deposition and the generation of the fine and uniform microstructures necessary to ensure proper functionality of LIGA components. We draw from both previously published work by external researchers in the field as well as from published and unpublished studies from within Sandia.

  5. Engastamento parcial de ligações viga-pilar em estruturas de concreto armado


    Alva,G. M. S.; Ferreira,M. A.; El Debs,A. L. H. C.


    Neste trabalho são apresentados os resultados experimentais de ensaios em ligações viga-pilar de concreto armado realizados na Escola de Engenharia de São Carlos - USP. Os referidos resultados experimentais concentram-se nas rotações relativas entre os elementos viga e pilar, importantes para a determinação da relação momento-rotação das ligações e da caracterização do comportamento semi-rígido das mesmas. Os dados experimentais foram obtidos a partir de ensaios de ligações viga-pilar de extr...

  6. Industrial Silicon Wafer Solar Cells

    Directory of Open Access Journals (Sweden)

    Dirk-Holger Neuhaus


    Full Text Available In 2006, around 86% of all wafer-based silicon solar cells were produced using screen printing to form the silver front and aluminium rear contacts and chemical vapour deposition to grow silicon nitride as the antireflection coating onto the front surface. This paper reviews this dominant solar cell technology looking into state-of-the-art equipment and corresponding processes for each process step. The main efficiency losses of this type of solar cell are analyzed to demonstrate the future efficiency potential of this technology. In research and development, more various advanced solar cell concepts have demonstrated higher efficiencies. The question which arises is “why are new solar cell concepts not transferred into industrial production more frequently?”. We look into the requirements a new solar cell technology has to fulfill to have an advantage over the current approach. Finally, we give an overview of high-efficiency concepts which have already been transferred into industrial production.

  7. Automated Array Assembly Task In-depth Study of Silicon Wafer Surface Texturizing (United States)

    Jones, G. T.; Rhee, S. S.


    Several aspects of silicon wafer surface texturizing were studied. A low cost cleaning method that utilizes recycled Freon in an ultrasonic vapor degreaser to remove organic and inorganic contaminants from the surface of silicon wafers as received from silicon suppliers was investigated. The use of clean dry air and high throughout wafer batch drying techniques was shown to lower the cost of wafer drying. A two stage texturizing process was examined for suitability in large scale production. Also, an in-depth gettering study with the two stage texturizing process was performed for the enhancement of solar cell efficiency, minimization of current versus voltage curve dispersion, and improvement in process reproducibility. The 10% efficiency improvement goal was exceeded for the near term implementation of flat plate photovoltaic cost reduction.

  8. Silicon Wafer X-ray Mirror Project (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks; (1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  9. Silicon Wafer X-ray Mirror Project (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks;(1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  10. Modelling deformation and fracture in confectionery wafers

    Energy Technology Data Exchange (ETDEWEB)

    Mohammed, Idris K.; Charalambides, Maria N.; Williams, J. Gordon; Rasburn, John [Mechanical Engineering Department, Imperial College London, South Kensington, London, SW7 2AZ, United Kingdom and Nestec York Ltd., Nestlé Product Technology Centre, Haxby Road, PO Box 204, York YO91 1XY (United Kingdom)


    The aim of this research is to model the deformation and fracture behaviour of brittle wafers often used in chocolate confectionary products. Three point bending and compression experiments were performed on beam and circular disc samples respectively to determine the 'apparent' stress-strain curves in bending and compression. The deformation of the wafer for both these testing types was observed in-situ within an SEM. The wafer is modeled analytically and numerically as a composite material with a core which is more porous than the skins. X-ray tomography was used to generate a three dimensional volume of the wafer microstructure which was then meshed and used for quantitative analysis. A linear elastic material model, with a damage function and element deletion, was used and the XMT generated architecture was loaded in compression. The output from the FE simulations correlates closely to the load-deflection deformation observed experimentally.

  11. Modelling deformation and fracture in confectionery wafers (United States)

    Mohammed, Idris K.; Charalambides, Maria N.; Williams, J. Gordon; Rasburn, John


    The aim of this research is to model the deformation and fracture behaviour of brittle wafers often used in chocolate confectionary products. Three point bending and compression experiments were performed on beam and circular disc samples respectively to determine the 'apparent' stress-strain curves in bending and compression. The deformation of the wafer for both these testing types was observed in-situ within an SEM. The wafer is modeled analytically and numerically as a composite material with a core which is more porous than the skins. X-ray tomography was used to generate a three dimensional volume of the wafer microstructure which was then meshed and used for quantitative analysis. A linear elastic material model, with a damage function and element deletion, was used and the XMT generated architecture was loaded in compression. The output from the FE simulations correlates closely to the load-deflection deformation observed experimentally.

  12. Wafer Cakes of Improved Amino Acid Structure

    Directory of Open Access Journals (Sweden)

    Roksolana Boidunyk


    Full Text Available The article presents the results of the study of the amino acid composition of newly developed wafer cakes with adipose fillings combined with natural additives. The appropriateness of the using non-traditional raw materials (powder of willow herb, poppy oilcake, carob, as well as skimmed milk powder in order to increase the biological value of wafer cakes and improve their amino acid composition is proven.

  13. Development of wafers with lowered glycemic index

    Directory of Open Access Journals (Sweden)

    N. N. Popova


    Full Text Available The negative impact on an organism is made by lack of culture of food of the population and low physical activity. It leads to violations of carbohydrate and lipidic exchange, development of obesity, diabetes, cardiovascular and other diseases. Relevance of development of foodstuff, in particular – the confectionery promoting decrease in risk of developing of such pathologies is proved. A research objective – development of a compounding of wafers with the lowered glycemic index. As an object of a research the wafers baked in house conditions are chosen. In work various characteristics are analysed (hygroscopicity, a cariogenicity sweet degree, power value, a glicemic index and a glycemic response the sweetening substances, the choice of fructose as sugar substitute for production of wafers with the lowered glycemic index is reasonable. By optimization of a compounding of wafers the amount of sugar was replaced with amount of sweetener, equivalent on sweet. As a result of predesigns the interval of a variation of amount of the fructose entered into a compounding of wafers is established. Further assessment of the indicators of quality forming consumer demand of products – appearance, taste, a smell, existence of a crunch is carried out. Humidity of the received wafers after their production and in the course of storage is also investigated. Decrease in a glycemic index was fixed by amount of glucose in blood. Its measurements saw by means of the glucose meter "on an empty stomach" and after the use of wafers to a complete recovery of level of sugar in blood. The confectionery made on the optimized compounding practically doesn't differ on caloric content from a control sample, and glucose level in blood after their use on about 20% below.

  14. Yield Improvement for 3D Wafer-to-Wafer Stacked Memories

    NARCIS (Netherlands)

    Taouil, M.; Hamdioui, S.


    Recent enhancements in process development enable the fabrication of three dimensional stacked ICs (3D-SICs) such as memories based on Wafer-to-Wafer (W2W) stacking. One of the major challenges facing W2W stacking is the low compound yield. This paper investigates compound yield improvement for W2W

  15. Laser cutting sandwich structure glass-silicon-glass wafer with laser induced thermal-crack propagation (United States)

    Cai, Yecheng; Wang, Maolu; Zhang, Hongzhi; Yang, Lijun; Fu, Xihong; Wang, Yang


    Silicon-glass devices are widely used in IC industry, MEMS and solar energy system because of their reliability and simplicity of the manufacturing process. With the trend toward the wafer level chip scale package (WLCSP) technology, the suitable dicing method of silicon-glass bonded structure wafer has become necessary. In this paper, a combined experimental and computational approach is undertaken to investigate the feasibility of cutting the sandwich structure glass-silicon-glass (SGS) wafer with laser induced thermal-crack propagation (LITP) method. A 1064 nm semiconductor laser cutting system with double laser beams which could simultaneously irradiate on the top and bottom of the sandwich structure wafer has been designed. A mathematical model for describing the physical process of the interaction between laser and SGS wafer, which consists of two surface heating sources and two volumetric heating sources, has been established. The temperature stress distribution are simulated by using finite element method (FEM) analysis software ABAQUS. The crack propagation process is analyzed by using the J-integral method. In the FEM model, a stationary planar crack is embedded in the wafer and the J-integral values around the crack front edge are determined using the FEM. A verification experiment under typical parameters is conducted and the crack propagation profile on the fracture surface is examined by the optical microscope and explained from the stress distribution and J-integral value.

  16. Evaluation of a cyanoacrylate dressing to manage peristomal skin alterations under ostomy skin barrier wafers. (United States)

    Milne, Catherine T; Saucier, Darlene; Trevellini, Chenel; Smith, Juliet


    Peristomal skin alterations under ostomy barrier wafers are a commonly reported problem. While a number of interventions to manage this issue have been reported, the use of a topically applied cyanoacrylate has received little attention. This case series describes the use of a topical cyanoacrylate for the management of peristomal skin alterations in persons living with an ostomy. Using a convenience sample, the topical cyanoacrylate dressing was applied to 11 patients with peristomal skin disruption under ostomy wafers in acute care and outpatient settings. The causes of barrier function interruption were also addressed to enhance outcomes. Patients were assessed for wound discomfort using a Likert Scale, time to healing, and number of appliance changes. Patient satisfaction was also examined. Average reported discomfort levels were 9.5 out of 10 at the initial peristomal irritation assessment visit decreased to 3.5 at the first wafer change and were absent by the second wafer change. Wafers had increasing wear time between changes in both settings with acute care patients responding faster. Epidermal resurfacing occurred within 10.2 days in outpatients and within 7 days in acute care patients. Because of the skin sealant action of this dressing, immediate adherence of the wafer was reported at all pouch changes.

  17. Integrating III-V compound semiconductors with silicon using wafer bonding (United States)

    Zhou, Yucai


    From Main Street to Wall Street, everyone has felt the effects caused by the Internet revolution. The Internet has created a new economy in the New Information Age and has brought significant changes in both business and personal life. This revolution has placed strong demands for higher bandwidth and higher computing speed due to high data traffic on today's information highway. In order to alleviate this problem, growing interconnection bottlenecks in digital designs have to be solved. The most feasible and practical way is to replace the conventional electrical interconnect with an optical interconnect. Since silicon does not have the optical properties necessary to accommodate these optical interconnect requirements, III-V based devices, most of which are GaAs-based or InP-based, must be intimately interconnected with the Si circuit at chip level. This monolithic integration technology enables the development of both intrachip and interchip optical connectors to take advantage of the enormous bandwidth provided by both high-performance very-large-scale integrated (VLSI) circuits and allied fiber and free-space optical technologies. However, lattice mismatch and thermal expansion mismatches between III-V materials and Si create enormous challenges for developing a feasible technology to tackle this problem. Among all the available approaches today, wafer bonding distinguishes itself as the most promising technology for integration due to its ability to overcome the constraints of both lattice constant mismatch and thermal expansion coefficient differences and even strain due to the crystal orientation. We present our development of wafer bonding technology for integrating III-V with Si in my dissertation. First, the pick-and-place multiple-wafer bonding technology was introduced. Then we systematically studied the wafer bonding of GaAs and InP with Si. Both high temperature wafer fusion and low/room temperature (LT/RT) wafer bonding have been investigated for

  18. Full-field wafer warpage measurement technique (United States)

    Hsieh, H. L.; Lee, J. Y.; Huang, Y. G.; Liang, A. J.; Sun, B. Y.


    An innovative moiré technique for full-field wafer warpage measurement is proposed in this study. The wafer warpage measurement technique is developed based on moiré method, Talbot effect, scanning profiling method, stroboscopic, instantaneous phase-shift method, as well as four-step phase shift method, high resolution, high stability and full-field measurement capabilities can be easily achieved. According to the proposed full-field optical configuration, a laser beam is expanded into a collimated beam with a 2-inch diameter and projected onto the wafer surface. The beam is reflected by the wafer surface and forms a moiré fringe image after passing two circular gratings, which is then focused and captured on a CCD camera for computation. The corresponding moiré fringes reflected from the wafer surface are obtained by overlapping the images of the measuring grating and the reference grating. The moiré fringes will shift when wafer warpage occurs. The phase of the moiré fringes will change proportionally to the degree of warpage in the wafer, which can be measured by detecting variations in the phase shift of the moiré fringes in each detection points on the surface of the entire wafer. The phase shift variations of each detection points can be calculated via the instantaneous phase-shift method and the four-step phase-shift method. By adding up the phase shift variations of each detection points along the radii of the circular gratings, the warpage value and surface topography of the wafer can be obtained. Experiments show that the proposed method is capable of obtaining test results similar to that of a commercial sensor, as well as performing accurate measurements under high speed rotation of 1500rpm. As compared to current warpage measurement methods such as the beam optical method, confocal microscopy, laser interferometry, shadow moiré method, and structured light method, this proposed technique has the advantage of full-field measurement, high

  19. On-wafer high temperature characterization system (United States)

    Teodorescu, L.; ǎghici, F., Dr; Rusu, I.; Brezeanu, G.


    In this work a on-wafer high temperature characterization system for wide bandgap semiconductor devices and circuits has been designed, implemented and tested. The proposed system can perform the wafer temperature adjustment in a large domain, from the room temperature up to 3000C with a resolution better than +/-0.50C. In order to obtain both low-noise measurements and low EMI, the heating element of the wafer chuck is supplied in two ways: one is from a DC linear power supply connected to the mains electricity, another one is from a second DC unit powered by batteries. An original temperature control algorithm, different from classical PID, is used to modify the power applied to the chuck.

  20. LIGA-fabricated compact mm-wave linear accelerator cavities.

    Energy Technology Data Exchange (ETDEWEB)

    Song, J.J.; Bajikar, S.S.; DeCarlo, F.; Kang, Y.W.; Kustom, R.L.; Mancini, D.C.; Nassiri, A.; Lai, B.; Feinerman, A.D.; White, V.


    Millimeter-wave rf cavities for use in linear accelerators, free-electron lasers, and mm-wave undulatory are under development at Argonne National Laboratory. Typical cavity dimensions are in the 1000 mm range, and the overall length of the accelerator structure, which consists of 30-100 cavities, is about 50-100 mm. An accuracy of 0.2% in the cavity dimensions is necessary in order to achieve a high Q-factor of the cavity. To achieve this these structures are being fabricated using deep X-ray lithography, electroforming, and assembly (LIGA). The first prototype cavity structures are designed for 108 GHz and 2p/3-mode operation. Input and output couplers are integrated with the cavity structures. The cavities are fabricated on copper substrates by electroforming copper into 1-mm-thick PMMA resists patterned by deep x-ray lithography and polishing the copper down to the desired thickness. These are fabricated separately and subsequently assembled with precision spacing and alignment using microspheres, optical fibers, or microfabricated spacers/alignment pieces. Details of the fabrication process, alignment, and assembly work are presented in here.

  1. An aluminum resist substrate for microfabrication by LIGA.

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, James J.; Boehme, Dale R.; Hauck, Cheryl A. (Lawrence Berkeley National Laboratory, Berkeley, CA); Yang, Chu-Yeu Peter; Hunter, Luke L.; Griffiths, Stewart K.; McLean, Dorrance E.; Aigeldinger, Georg; Hekmaty, Michelle A.; Hachman, John T.; Losey, Matthew W.; Skala, Dawn M.; Korellis, John S.; Friedmann, Thomas Aquinas (Sandia National Laboratories, Albuquerque, NM); Yang, Nancy Y. C.; Lu, Wei-Yang


    Resist substrates used in the LIGA process must provide high initial bond strength between the substrate and resist, little degradation of the bond strength during x-ray exposure, acceptable undercut rates during development, and a surface enabling good electrodeposition of metals. Additionally, they should produce little fluorescence radiation and give small secondary doses in bright regions of the resist at the substrate interface. To develop a new substrate satisfying all these requirements, we have investigated secondary resist doses due to electrons and fluorescence, resist adhesion before exposure, loss of fine features during extended development, and the nucleation and adhesion of electrodeposits for various substrate materials. The result of these studies is a new anodized aluminum substrate and accompanying methods for resist bonding and electrodeposition. We demonstrate successful use of this substrate through all process steps and establish its capabilities via the fabrication of isolated resist features down to 6 {micro}m, feature aspect ratios up to 280 and electroformed nickel structures at heights of 190 to 1400 {micro}m. The minimum mask absorber thickness required for this new substrate ranges from 7 to 15 {micro}m depending on the resist thickness.

  2. Wafer level 3-D ICs process technology

    CERN Document Server

    Tan, Chuan Seng; Reif, L Rafael


    This book focuses on foundry-based process technology that enables the fabrication of 3-D ICs. The core of the book discusses the technology platform for pre-packaging wafer lever 3-D ICs. However, this book does not include a detailed discussion of 3-D ICs design and 3-D packaging. This is an edited book based on chapters contributed by various experts in the field of wafer-level 3-D ICs process technology. They are from academia, research labs and industry.

  3. Palladium-based on-wafer electroluminescence studies of GaN-based LED structures

    Energy Technology Data Exchange (ETDEWEB)

    Salcianu, C.O.; Thrush, E.J.; Humphreys, C.J. [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Plumb, R.G. [Centre for Photonic Systems, Department of Engineering, University of Cambridge, Cambridge CB3 0FD (United Kingdom); Boyd, A.R.; Rockenfeller, O.; Schmitz, D.; Heuken, M. [AIXTRON AG, Kackertstr. 15-17, 52072 Aachen (Germany)


    Electroluminescence (EL) testing of Light Emitting Diode (LED) structures is usually done at the chip level. Assessing the optical and electrical properties of LED structures at the wafer scale prior to their processing would improve the cost effectiveness of producing LED-lamps. A non-destructive method for studying the luminescence properties of the structure at the wafer-scale is photoluminescence (PL). However, the relationship between the on-wafer PL data and the final device EL can be less than straightforward (Y. H Aliyu et al., Meas. Sci. Technol. 8, 437 (1997)) as the two techniques employ different carrier injection mechanisms. This paper provides an overview of some different techniques in which palladium is used as a contact in order to obtain on-wafer electroluminescence information which could be used to screen wafers prior to processing into final devices. Quick mapping of the electrical and optical characteristics was performed using either palladium needle electrodes directly, or using the latter in conjunction with evaporated palladium contacts to inject both electrons and holes into the active region via the p-type capping layer of the structure. For comparison, indium was also used to make contact to the n-layer so that electrons could be directly injected into that layer. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Balance Competitivo en las Ligas Europeas de Baloncesto y la NBA

    Directory of Open Access Journals (Sweden)

    Jorge García - Unanue


    Full Text Available Las ligas deportivas dependen del equilibrio competitivo entre los equipos para ser atractivas para los espectadores, de ahí la aparición del balance competitivo. Por ello, las distintas ligas deportivas han adquirido diferentes formatos que determinarán su competitividad. El objetivo de este artículo es comparar el balance competitivo de la NBA y las principales ligas europeas, teniendo en cuenta la NBA en su conjunto y cada una de sus conferencias de forma independiente. Las variables utilizadas para medir el balance competitivo han sido el índice Hirschman-Herfindal y las ratios C5 y C8. Los resultados muestran un mejor balance competitivo de la NBA en conjunto respecto a las ligas europeas, sin embargo estas diferencias desaparecen al analizar las conferencias de forma independiente. Se concluye que al tener en cuenta cada una de las conferencias de forma independiente, con una estructura más similar a las ligas europeas, se presenta un balance competitivo parecido bajo los indicadores utilizados. Sin embargo, la NBA incluye limitaciones en la competición que siguen favoreciendo la posibilidad de que sea más atractiva para el espectador.

  5. Silicon waveguides produced by wafer bonding

    DEFF Research Database (Denmark)

    Poulsen, Mette; Jensen, Flemming; Bunk, Oliver


    X-ray waveguides are successfully produced employing standard silicon technology of UV photolithography and wafer bonding. Contrary to theoretical expectations for similar systems even 100 mu m broad guides of less than 80 nm height do not collapse and can be used as one dimensional waveguides...

  6. Low-cost silicon wafer dicing using a craft cutter

    KAUST Repository

    Fan, Yiqiang


    This paper reports a low-cost silicon wafer dicing technique using a commercial craft cutter. The 4-inch silicon wafers were scribed using a crafter cutter with a mounted diamond blade. The pre-programmed automated process can reach a minimum die feature of 3 mm by 3 mm. We performed this scribing process on the top polished surface of a silicon wafer; we also created a scribing method for the back-unpolished surface in order to protect the structures on the wafer during scribing. Compared with other wafer dicing methods, our proposed dicing technique is extremely low cost (lower than $1,000), and suitable for silicon wafer dicing in microelectromechanical or microfluidic fields, which usually have a relatively large die dimension. The proposed dicing technique is also usable for dicing multiple project wafers, a process where dies of different dimensions are diced on the same wafer.

  7. Wafer plane inspection for advanced reticle defects (United States)

    Nagpal, Rajesh; Ghadiali, Firoz; Kim, Jun; Huang, Tracy; Pang, Song


    Readiness of new mask defect inspection technology is one of the key enablers for insertion & transition of the next generation technology from development into production. High volume production in mask shops and wafer fabs demands a reticle inspection system with superior sensitivity complemented by a low false defect rate to ensure fast turnaround of reticle repair and defect disposition (W. Chou et al 2007). Wafer Plane Inspection (WPI) is a novel approach to mask defect inspection, complementing the high resolution inspection capabilities of the TeraScanHR defect inspection system. WPI is accomplished by using the high resolution mask images to construct a physical mask model (D. Pettibone et al 1999). This mask model is then used to create the mask image in the wafer aerial plane. A threshold model is applied to enhance the inspectability of printing defects. WPI can eliminate the mask restrictions imposed on OPC solutions by inspection tool limitations in the past. Historically, minimum image restrictions were required to avoid nuisance inspection stops and/or subsequent loss of sensitivity to defects. WPI has the potential to eliminate these limitations by moving the mask defect inspections to the wafer plane. This paper outlines Wafer Plane Inspection technology, and explores the application of this technology to advanced reticle inspection. A total of twelve representative critical layers were inspected using WPI die-to-die mode. The results from scanning these advanced reticles have shown that applying WPI with a pixel size of 90nm (WPI P90) captures all the defects of interest (DOI) with low false defect detection rates. In validating CD predictions, the delta CDs from WPI are compared against Aerial Imaging Measurement System (AIMS), where a good correlation is established between WPI and AIMSTM.

  8. Development of a W-band Serpentine Waveguide Amplifier based on a UV-LIGA Microfabricated Copper Circuit (United States)


    beam tunnel [5,6] for a high-power, wideband W-band traveling-wave tube ( TWT ) amplifier. UV-LIGA is also a promising technique at higher... TWT ,” IEDM Tech. Dig., Vol. 33, p. 485-488, 1987. 5. C. D. Joye, et al., “Microfabrication of fine electron beam tunnels using UV-LIGA and embedded

  9. Contamination control: removing small particles from increasingly large wafers

    NARCIS (Netherlands)

    Jong, A.J. de; Donck, J.C.J. van der; Huijser, T.; Kievit, O.; Koops, R.; Koster, N.B.; Molkenboer, F.T.; Theulings, A.M.M.G.


    With the introduction of 450 mm wafers, which are considerably larger than the currently largest wafers of 300mm, handling with side grippers is no longer possible and backside grippers are required. Backside gripping increases the possible buildup of particles on the backside of the wafers with

  10. Fabrication of High Aspect Ratio Through-Wafer Vias in CMOS Wafers for 3-D Packaging Applications

    DEFF Research Database (Denmark)

    Rasmussen, Frank Engel; Frech, J.; Heschel, M.


    A process for fabrication of through-wafer vias in CMOS wafers is presented. The process presented offers simple and well controlled fabrication of through-wafer vias using DRIE formation of wafer through-holes, low temperature deposition of through-hole insulation, doubled sided sputtering of Cr...... the use of a CVD deposited polymer, Parylene C, whereas electroless deposition of Cu ensures even distribution of the via metallization....

  11. Análise da vida à fadiga de ligações soldadas em T


    Velhinho, Fábio Emanuel Gil


    Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica O estudo da resistência à fadiga de estruturas soldadas é um assunto complexo, que depende de vários factores, nomeadamente: da geometria do cordão de soldadura resultante, do processo de soldadura utilizado na produção da ligação soldada, do tipo de ligação soldada, das tensões residuais resultantes do processo de soldadura e das zonas afectadas pelo calor de soldadura, só para nomear alguns dos factores de que depende a r...

  12. Size of silicon strip sensor from 6 inch wafer (right) compared to that from a 4 inch wafer (left).

    CERN Multimedia

    Honma, Alan


    Silicon strip sensors made from 6 inch wafers will allow for much larger surface area coverage at a reduced cost per unit surface area. A prototype sensor of size 8cm x 11cm made by Hamamatsu from a 6 inch wafer is shown next to a traditional 6cm x 6cm sensor from a 4 inch wafer.

  13. Development of the LIGA process using a superconducting compact synchrotron light source; Chodendo kogata synchrotron kogen wo mochiita LIGA process no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takada, H.; Hirata, Y.; Okuyama, H.; Numazawa, T. [Sumitomo Electric Industries, Ltd., Osaka (Japan)


    This paper is devoted to the description of the LIGA process using a 60OMeV superconducting compact synchrotron light source. The realization of deep-etch x-ray lithography is based on a new resist and mask. The resist is made of a copolymer of methyl methacrylate (MMA) and methacryl acid (MAA). The main benefit is its high sensitivity, which is one order of magnitude greater than that of polymethyl methacrylate (PMMA) used in the LIGA process. The mask is composed of a 2{mu}m thick silicon nitride membrane with high transparency supporting tungsten absorber which is a at results about deep-etch x-ray lithography, electroforming and molding 5{mu}m-thick. Experiment techniques are presented. Micro-ultrasonic transmitter obtained with these techniques is also shown. The purpose of this study is the realization of low cost micro-components for a variety of industrial applications. 7 refs., 15 figs., 1 tab.

  14. Local indicators of geocoding accuracy (LIGA: theory and application

    Directory of Open Access Journals (Sweden)

    Jacquez Geoffrey M


    Full Text Available Abstract Background Although sources of positional error in geographic locations (e.g. geocoding error used for describing and modeling spatial patterns are widely acknowledged, research on how such error impacts the statistical results has been limited. In this paper we explore techniques for quantifying the perturbability of spatial weights to different specifications of positional error. Results We find that a family of curves describes the relationship between perturbability and positional error, and use these curves to evaluate sensitivity of alternative spatial weight specifications to positional error both globally (when all locations are considered simultaneously and locally (to identify those locations that would benefit most from increased geocoding accuracy. We evaluate the approach in simulation studies, and demonstrate it using a case-control study of bladder cancer in south-eastern Michigan. Conclusion Three results are significant. First, the shape of the probability distributions of positional error (e.g. circular, elliptical, cross has little impact on the perturbability of spatial weights, which instead depends on the mean positional error. Second, our methodology allows researchers to evaluate the sensitivity of spatial statistics to positional accuracy for specific geographies. This has substantial practical implications since it makes possible routine sensitivity analysis of spatial statistics to positional error arising in geocoded street addresses, global positioning systems, LIDAR and other geographic data. Third, those locations with high perturbability (most sensitive to positional error and high leverage (that contribute the most to the spatial weight being considered will benefit the most from increased positional accuracy. These are rapidly identified using a new visualization tool we call the LIGA scatterplot. Herein lies a paradox for spatial analysis: For a given level of positional error increasing sample density

  15. Carbon dioxide capture using resin-wafer electrodeionization (United States)

    Lin, YuPo J.; Snyder, Seth W.; Trachtenberg, Michael S.; Cowan, Robert M.; Datta, Saurav


    The present invention provides a resin-wafer electrodeionization (RW-EDI) apparatus including cathode and anode electrodes separated by a plurality of porous solid ion exchange resin wafers, which when in use are filled with an aqueous fluid. The apparatus includes one or more wafers comprising a basic ion exchange medium, and preferably includes one or more wafers comprising an acidic ion exchange medium. The wafers are separated from one another by ion exchange membranes. The fluid within the acidic and/or basic ion exchange wafers preferably includes, or is in contact with, a carbonic anhydrase (CA) enzyme to facilitate conversion of bicarbonate ion to carbon dioxide within the acidic medium. A pH suitable for exchange of CO.sub.2 is electrochemically maintained within the basic and acidic ion exchange wafers by applying an electric potential across the cathode and anode.

  16. Defect detection in unpolished Si wafers by digital shearography (United States)

    Udupa, Ganesha; Ngoi, B. K. A.; Goh, H. C. Freddy; Yusoff, M. N.


    Defects in silicon wafers have been of great scientific and technological interest since before the earliest days of the silicon transistor. Recently much attention has been focused on crystal originated pits on the polished surface of the wafer. These defects have been shown to contribute to gate dielectric breakdown. The present work relates to surface and/or subsurface defect inspection systems for semiconductor industries and particularly to an inspection system for defects such as swirl defects and groups of particles in unpolished silicon wafers before the wafer reclamation and/or the wafer fabrication process using a digital shearography technique. The method described here relates specifically to semiconductor wafers, but may be generalized to any other samples. In the present work, surface or subsurface defects are detected and evaluated by stressing the silicon wafer while looking for defect-induced anomalies in a fringe pattern, generated by the interference of two speckle patterns, in the CCD camera and digital image processing.

  17. Devices using resin wafers and applications thereof (United States)

    Lin, YuPo J [Naperville, IL; Henry, Michael P [Batavia, IL; Snyder, Seth W [Lincolnwood, IL; Martin, Edward [Libertyville, IL; Arora, Michelle [Woodridge, IL; de la Garza, Linda [Woodridge, IL


    Devices incorporating a thin wafer of electrically and ionically conductive porous material made by the method of introducing a mixture of a thermoplastic binder and one or more of anion exchange moieties or cation exchange moieties or mixtures thereof and/or one or more of a protein capture resin and an electrically conductive material into a mold. The mixture is subjected to temperatures in the range of from about C. to about C. at pressures in the range of from about 0 to about 500 psig for a time in the range of from about 1 to about 240 minutes to form thin wafers. Devices include electrodeionization and separative bioreactors in the production of organic and amino acids, alcohols or esters for regenerating cofactors in enzymes and microbial cells.

  18. Optimal Wafer Cutting in Shuttle Layout Problems

    DEFF Research Database (Denmark)

    Nisted, Lasse; Pisinger, David; Altman, Avri


    . The shuttle layout problem is frequently solved in two phases: first, a floorplan of the shuttle is generated. Then, a cutting plan is found which minimizes the overall number of wafers needed to satisfy the demand of each die type. Since some die types require special production technologies, only compatible...... dies can be cut from a given wafer, and each cutting plan must respect various constraints on where the cuts may be placed. We present an exact algorithm for solving the minimum cutting plan problem, given a floorplan of the dies. The algorithm is based on delayed column generation, where the pricing...... problem becomes a maximum vertex-weighted clique problem in which each clique consists of cutting compatible dies. The resulting branch-and-price algorithm is able to solve realistic cutting problems to optimality in a couple of seconds....

  19. VLED for Si wafer-level packaging (United States)

    Chu, Chen-Fu; Chen, Chiming; Yen, Jui-Kang; Chen, Yung-Wei; Tsou, Chingfu; Chang, Chunming; Doan, Trung; Tran, Chuong Anh


    In this paper, we introduced the advantages of Vertical Light emitting diode (VLED) on copper alloy with Si-wafer level packaging technologies. The silicon-based packaging substrate starts with a dou-ble-side polished p-type silicon wafer, then anisotropic wet etching technology is done to construct the re-flector depression and micro through-holes on the silicon substrate. The operating voltage, at a typical cur-rent of 350 milli-ampere (mA), is 3.2V. The operation voltage is less than 3.7V under higher current driving conditions of 1A. The VLED chip on Si package has excellent heat dissipation and can be operated at high currents up to 1A without efficiency degradation. The typical spatial radiation pattern emits a uniform light lambertian distribution from -65° to 65° which can be easily fit for secondary optics. The correlated color temperature (CCT) has only 5% variation for daylight and less than 2% variation for warm white, when the junction temperature is increased from 25°C to 110°C, suggesting a stable CCT during operation for general lighting application. Coupled with aspheric lens and micro lens array in a wafer level process, it has almost the same light distribution intensity for special secondary optics lighting applications. In addition, the ul-tra-violet (UV) VLED, featuring a silicon substrate and hard glass cover, manufactured by wafer level pack-aging emits high power UV wavelengths appropriate for curing, currency, document verification, tanning, medical, and sterilization applications.

  20. Tai Chi poveikis Parkinsono liga sergančiųjų pusiausvyrai bei mobilumui. Klinikinių tyrimų analizė


    Petrauskaitė, Monika


    Darbo objektas: Parkinsono liga sergančiųjų pusiausvyra, mobilumas. Hipotezė: Mes manome, kad Tai Chi pagerina žmonių, sergančių Parkinsono liga pusiausvyrą bei mobilumą. Darbo tikslas:nustatyti Tai chi poveikį Parkinsono liga sergančiųjų pusiausvyrai ir mobilumui. Darbo uždaviniai: 1. Analizuojant klinikinius tyrimus nustatyti Tai Chi poveikį sergančiųjų Parkinsono liga pusiausvyrai. 2. Analizuojant klinikinius tyrimus nustatyti Tai Chi poveikį Parkinsono liga sergančiųjų mobi...

  1. Wafer level test solutions for IR sensors (United States)

    Giessmann, Sebastian; Werner, Frank-Michael


    Wafer probers provide an established platform for performing electrical measurements at wafer level for CMOS and similar process technologies. For testing IR sensors, the requirements are beyond the standard prober capabilities. This presentation will give an overview about state of the art IR sensor probing systems reaching from flexible engineering solutions to automated production needs. Cooled sensors typically need to be tested at a target temperature below 80 K. Not only is the device temperature important but also the surrounding environment is required to prevent background radiation from reaching the device under test. To achieve that, a cryogenic shield is protecting the movable chuck. By operating that shield to attract residual gases inside the chamber, a completely contamination-free test environment can be guaranteed. The use of special black coatings are furthermore supporting the removal of stray light. Typically, probe card needles are operating at ambient (room) temperature when connecting to the wafer. To avoid the entrance of heat, which can result in distorted measurements, the probe card is fully embedded into the cryogenic shield. A shutter system, located above the probe field, is designed to switch between the microscope view to align the sensor under the needles and the test relevant setup. This includes a completely closed position to take dark current measurements. Another position holds a possible filter glass with the required aperture opening. The necessary infrared sources to stimulate the device are located above.

  2. Harmonic versus LigaSure hemostasis technique in thyroid surgery: A meta-analysis. (United States)

    Upadhyaya, Arun; Hu, Tianpeng; Meng, Zhaowei; Li, Xue; He, Xianghui; Tian, Weijun; Jia, Qiang; Tan, Jian


    Harmonic scalpel and LigaSure vessel sealing systems have been suggested as options for saving surgical time and reducing postoperative complications. The aim of the present meta-analysis was to compare surgical time, postoperative complications and other parameters between them in for the open thyroidectomy procedure. Studies were retrieved from MEDLINE, Cochrane Library, EMBASE and ISI Web of Science until December 2015. All the randomized controlled trials (RCTs) comparing Harmonic scalpel and LigaSure during open thyroidectomy were selected. Following data extraction, statistical analyses were performed. Among the 24 studies that were evaluated for eligibility, 7 RCTs with 981 patients were included. The Harmonic scalpel significantly reduced surgical time compared with LigaSure techniques (8.79 min; 95% confidence interval, -15.91 to -1.67; P=0.02). However, no significant difference was observed for the intraoperative blood loss, postoperative blood loss, duration of hospital stay, thyroid weight and serum calcium level postoperatively in either group. The present meta-analysis indicated superiority of Harmonic Scalpel only in terms of surgical time compared with LigaSure hemostasis techniques in open thyroid surgery.

  3. Cost-Efficient Wafer-Level Capping for MEMS and Imaging Sensors by Adhesive Wafer Bonding

    Directory of Open Access Journals (Sweden)

    Simon J. Bleiker


    Full Text Available Device encapsulation and packaging often constitutes a substantial part of the fabrication cost of micro electro-mechanical systems (MEMS transducers and imaging sensor devices. In this paper, we propose a simple and cost-effective wafer-level capping method that utilizes a limited number of highly standardized process steps as well as low-cost materials. The proposed capping process is based on low-temperature adhesive wafer bonding, which ensures full complementary metal-oxide-semiconductor (CMOS compatibility. All necessary fabrication steps for the wafer bonding, such as cavity formation and deposition of the adhesive, are performed on the capping substrate. The polymer adhesive is deposited by spray-coating on the capping wafer containing the cavities. Thus, no lithographic patterning of the polymer adhesive is needed, and material waste is minimized. Furthermore, this process does not require any additional fabrication steps on the device wafer, which lowers the process complexity and fabrication costs. We demonstrate the proposed capping method by packaging two different MEMS devices. The two MEMS devices include a vibration sensor and an acceleration switch, which employ two different electrical interconnection schemes. The experimental results show wafer-level capping with excellent bond quality due to the re-flow behavior of the polymer adhesive. No impediment to the functionality of the MEMS devices was observed, which indicates that the encapsulation does not introduce significant tensile nor compressive stresses. Thus, we present a highly versatile, robust, and cost-efficient capping method for components such as MEMS and imaging sensors.

  4. Fabricating Capacitive Micromachined Ultrasonic Transducers with Wafer Bonding Technique

    Directory of Open Access Journals (Sweden)

    Anil ARORA


    Full Text Available We report the fabrication of capacitive micromachined ultrasonic transducer by wafer bonding technique. Membrane is transferred from SOI wafer to the prime wafer having silicon dioxide cavity. The thickness of cavity height depends on silicon dioxide grown on prime wafer by dry/wet oxidation. Thinning of device wafer of SOI by oxidation, controls membrane thickness. Two wafers are bonded in vacuum under optimized controlled parameters. Using this method, we can get single crystal silicon as membrane, whose mechanical and electrical parameters are well known. Silicon membrane is free from stress and density variation. Focused Ion Beam etching and laser Doppler Vibrometer were used to do structural and electrical characterization respectively. The measured resonance frequency of fabricated device i.e. 2.24 MHz is much closer to the designed value i.e. 2.35 MHz.

  5. Electrooptic shutter devices utilizing PLZT ceramic wafers

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, A.L.


    Optical transparency was achieved in lead zirconate-titanate ferroelectric ceramics by substituting moderate amounts of the element lanthanum (8 to 12%) for lead. These compositions exhibit the quadratic (Kerr) electrooptic effect. The excellent optical qualities of these materials (designated PLZT) has permitted the practical utilization of their electrooptic properties in a number of devices. All of these devices utilize the classic Kerr cell arrangement. A PLZT wafer with optical axis oriented at 45/sup 0/ with respect to the axes of polarization is sandwiched between crossed polarizers. Application of an electric field via an interdigital array of electrodes on opposing wafer surfaces forces the PLZT material into a tetragonal state with the resulting induced birefringence proportional to the square of the applied electric field. Hence, the electrooptic wafer provides a retardation of light so that a component is passed by the second crossed polarizer to achieve an ON or open state. Maximum transmission is achieved when the retardation is half-wave. Shutter devices developed by Sandia and those in continuing development are described with respect to operational characteristics and physical configuration. The devices range in size from very small apertures of 50 x 2 mm with center-to-center repeat dimensions of 125 - to very large - apertures of 15.2 cm in single pieces and mosaics with apertures of 15.2 cm x 20.3 cm. Major efforts have centered on shutter development for the protection of aircrew from eye-damaging weapon effects. Other devices are also described which: provide eye protection for welders, protect vidicon tubes, function as page composers for holographic memories serve as large aperture photographic shutters, provide stereoscopic three-dimensional TV displays, and serve as data links in a fiber-optic transmission path.

  6. Candida parapsilosis meningitis associated with Gliadel (BCNU) wafer implants.

    LENUS (Irish Health Repository)

    O'brien, Deirdre


    A 58-year old male presented with meningitis associated with subgaleal and subdural collections 6 weeks following a temporal craniotomy for resection of recurrent glioblastoma multiforme and Gliadel wafer implantation. Candida parapsilosis was cultured from cerebrospinal fluid (CSF) and Gliadel wafers removed during surgical debridement. He was successfully treated with liposomal amphotericin B. To our knowledge, this is the first reported case of Candida parapsilosis meningitis secondary to Gliadel wafer placement.

  7. Candida parapsilosis meningitis associated with Gliadel (BCNU) wafer implants.

    LENUS (Irish Health Repository)

    O'Brien, Deirdre


    A 58-year old male presented with meningitis associated with subgaleal and subdural collections 6 weeks following a temporal craniotomy for resection of recurrent glioblastoma multiforme and Gliadel wafer implantation. Candida parapsilosis was cultured from cerebrospinal fluid (CSF) and Gliadel wafers removed during surgical debridement. He was successfully treated with liposomal amphotericin B. To our knowledge, this is the first reported case of Candida parapsilosis meningitis secondary to Gliadel wafer placement.

  8. Micro-miniature gas chromatograph column disposed in silicon wafers (United States)

    Yu, Conrad M.


    A micro-miniature gas chromatograph column is fabricated by forming matching halves of a circular cross-section spiral microcapillary in two silicon wafers and then bonding the two wafers together using visual or physical alignment methods. Heating wires are deposited on the outside surfaces of each wafer in a spiral or serpentine pattern large enough in area to cover the whole microcapillary area inside the joined wafers. The visual alignment method includes etching through an alignment window in one wafer and a precision-matching alignment target in the other wafer. The two wafers are then bonded together using the window and target. The physical alignment methods include etching through vertical alignment holes in both wafers and then using pins or posts through corresponding vertical alignment holes to force precision alignment during bonding. The pins or posts may be withdrawn after curing of the bond. Once the wafers are bonded together, a solid phase of very pure silicone is injected in a solution of very pure chloroform into one end of the microcapillary. The chloroform lowers the viscosity of the silicone enough that a high pressure hypodermic needle with a thumbscrew plunger can force the solution into the whole length of the spiral microcapillary. The chloroform is then evaporated out slowly to leave the silicone behind in a deposit.

  9. Viabilidade da utilização da liga Sn - Ni65 - 35 eletrodepositada em contatos eletricos


    Eliane Maria Grigoletto


    Resumo: A viabilidade da utilização da liga de estanho-níquel 65-35 eletrodepositada em contatos elétricos usados em baixa voltagem-baixa corrente foi verificada pelo estudo das propriedades deste recobrimento. As amostras foram preparadas com um banho comercial e a proporção dos elementos na liga foi de 65% de estanho e 35% de níquel em peso. A composição e estrutura da liga foram analisadas por difração de Raios X. A resistência à corrosão do recobrimento da liga de estanho-níquel em meio a...

  10. New overlay measurement technique with an i-line stepper using embedded standard field image alignment marks for wafer bonding applications (United States)

    Kulse, P.; Sasai, K.; Schulz, K.; Wietstruck, M.


    In the last decades the semiconductor technology has been driven by Moore's law leading to high performance CMOS technologies with feature sizes of less than 10 nm [1]. It has been pointed out that not only scaling but also the integration of novel components and technology modules into CMOS/BiCMOS technologies is becoming more attractive to realize smart and miniaturized systems [2]. Driven by new applications in the area of communication, health and automation, new components and technology modules such as BiCMOS embedded RF-MEMS, high-Q passives, Sibased microfluidics and InP-SiGe BiCMOS heterointegration have been demonstrated [3-6]. In contrast to standard VLSI processes fabricated on front side of the silicon wafer, these new technology modules require addition backside processing of the wafer; thus an accurate alignment between the front and backside of the wafer is mandatory. In previous work an advanced back to front side alignment technique and implementation into IHP's 0.25/0.13 μm high performance SiGe:C BiCMOS backside process module has been presented [7]. The developed technique enables a high resolution and accurate lithography on the backside of BiCMOS wafer for additional backside processing. In addition to the aforementioned back side process technologies, new applications like Through-Silicon Vias (TSV) for interposers and advanced substrate technologies for 3D heterogeneous integration demand not only single wafer fabrication but also processing of wafer stacks provided by temporary and permanent wafer bonding [8]. Therefore, the available overlay measurement techniques are not suitable if overlay and alignment marks are realized at the bonding interface of a wafer stack which consists of both a silicon device and a silicon carrier wafer. The former used EVG 40NT automated overlay measurement system, which use two opposite positioned microscopes inspecting simultaneous the wafer back and front side, is not capable measuring embedded overlay

  11. Estudo de ligas cataliticas de paladio e ouro atraves de espectroscopia de fotoeletrons


    Pedro Augusto de Paula


    Resumo: Neste trabalho desenvolvemos o estudo sistemático de urna série de ligas PdxAu1-x, variando de Pd puro (x = 1) até Au puro (x = 0). A análise desse sistema por ESCA tem como objetivo obter informações sobre mudanças na estrutura eletrônica de Pd e Au quando da formação da liga. Medindo a variação da energia cinética da linha Au Auger MNN, chegamos à diferença entre os níveis de Fermi de Pd e Au, valor esse que concorda com resultado obtido através de medidas independentes. Co...

  12. New technique using LigaSure for endoscopic mucomyotomy of Zenker's diverticulum

    DEFF Research Database (Denmark)

    Nielsen, Hans Ulrik Kjaerem; Trolle, Waldemar; Rubek, Niclas


    and vomiting immediately postoperatively and was hours later diagnosed with a perforation. The patient was successfully treated with antibiotics. At follow-up this patient was on a normal diet. At follow-up after 2 to 8 weeks, all patients were relieved of their preoperative symptoms. At follow-up after 5...... condition. As a new operative instrument, the LigaSure technique constitutes in our opinion a valid and easy alternative for treatment of Zenker's diverticulum compared to other endoscopic techniques....

  13. A Transdermal Drug Delivery System Based on LIGA Technology and Soft Lithography (United States)

    Matteucci, Marco; Perennes, Frederic; Marmiroli, Benedetta; Di Fabrizio, Enzo


    This report presents a transdermal drug delivery system based on LIGA fabricated microparts. It is a portable device combining a magnetically actuated micro gear pump with a microneedle array. The fluidic behaviour of the system is analyzed in order to predict its performance according to the dimension of the microparts and then compared to experimental data. The manufacturing process of both micropump and microneedle array are described.

  14. LigaSure small jaws versus cold knife dissection in superficial parotidectomy

    DEFF Research Database (Denmark)

    Hahn, Christoffer Holst; Sørensen, Christian Hjort


    parotidectomy, and 19 patients had cold knife parotidectomy. Operative time, blood loss, facial palsy and other complications were assessed. The use of LigaSure was associated with a significant reduction in mean operative time (128 min vs. 155, p = 0.04) and intraoperative blood loss (40 mL vs. 115 mL, p ...

  15. Diamond-like nanocomposite coatings for LIGA-fabricated nickel alloy parts.

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, Somuri V.; Scharf, Thomas W.


    A commercial plasma enhanced chemical vapor deposition (PECVD) technique with planetary substrate rotation was used to apply a thin (200-400 nm thick) conformal diamond-like carbon (DLC) coating (known as a diamond-like nanocomposite (DLN)) on LIGA fabricated Ni-Mn alloy parts. The PECVD technique is known to overcome the drawbacks associated with the line-of-sight nature of physical vapor deposition (PVD) and substrate heating inherent with traditional chemical vapor deposition (CVD). The purpose of the present study is to characterize the coverage, adhesion, and tribological (friction and wear) behavior of DLN coatings applied to planar and sidewall surfaces of small featured LIGA Ni-Mn fabricated parts, e.g. 280 {micro}m thick sidewalls. Friction and wear tests were performed in dry nitrogen, dry air, and air with 50% RH at Hertzian contact pressures ranging from 0.3 to 0.6 GPa. The friction coefficient of bare Ni-Mn alloy was determined to be 0.9. In contrast, low friction coefficients ({approx}0.02 in dry nitrogen and {approx}0.2 in 50% RH air) and minimal amount of wear were exhibited for the DLN coated LIGA Ni-Mn alloy parts and test coupons. This behavior was due to the ability of the coating to transfer to the rubbing counterface providing low interfacial shear at the sliding contact; resultantly, coating one surface was adequate for low friction and wear. In addition, a 30 nm thick titanium bond layer was determined to be necessary for good adhesion of DLN coating to Ni-Mn alloy substrates. Raman spectroscopy and cross-sectional SEM with energy dispersive x-ray analysis revealed that the DLN coatings deposited by the PECVD with planetary substrate rotation covered both the planar and sidewall surfaces of LIGA fabricated parts, as well as narrow holes of 300 {micro}m (0.012 inch) diameter.

  16. Direct Electroplating on Highly Doped Patterned Silicon Wafers

    NARCIS (Netherlands)

    Vargas Llona, Laura Dolores; Jansen, Henricus V.; Elwenspoek, Michael Curt

    Nickel thin films have been electrodeposited directly on highly doped silicon wafers after removal of the native oxide layer. These substrates conduct sufficiently well to allow deposition using a periferical electrical contact on the wafer. Films 2 μm thick were deposited using a nickel sulfamate

  17. Si-to-Si wafer bonding using evaporated glass

    DEFF Research Database (Denmark)

    Reus, Roger De; Lindahl, M.


    Anodic bonding of Si to Si four inch wafers using evaporated glass was performed in air at temperatures ranging from 300°C to 450°C. Although annealing of Si/glass structures around 340°C for 15 minutes eliminates stress, the bonded wafer pairs exhibit compressive stress. Pull testing revealed...

  18. Wafer bonding using Cu-Sn intermetallic bonding layers

    NARCIS (Netherlands)

    Flötgen, C.; Pawlak, M.; Pabo, E.; Wiel, H.J. van de; Hayes, G.R.; Dragoi, V.


    Wafer-level Cu-Sn intermetallic bonding is an interesting process for advanced applications in the area of MEMS and 3D interconnects. The existence of two intermetallic phases for Cu-Sn system makes the wafer bonding process challenging. The impact of process parameters on final bonding layer

  19. Semiconductor industry wafer fab exhaust management

    CERN Document Server

    Sherer, Michael J


    Given the myriad exhaust compounds and the corresponding problems that they can pose in an exhaust management system, the proper choice of such systems is a complex task. Presenting the fundamentals, technical details, and general solutions to real-world problems, Semiconductor Industry: Wafer Fab Exhaust Management offers practical guidance on selecting an appropriate system for a given application. Using examples that provide a clear understanding of the concepts discussed, Sherer covers facility layout, support facilities operations, and semiconductor process equipment, followed by exhaust types and challenges. He reviews exhaust point-of-use devices and exhaust line requirements needed between process equipment and the centralized exhaust system. The book includes information on wet scrubbers for a centralized acid exhaust system and a centralized ammonia exhaust system and on centralized equipment to control volatile organic compounds. It concludes with a chapter devoted to emergency releases and a separ...

  20. Wafer-scale fabrication of polymer distributed feedback lasers

    DEFF Research Database (Denmark)

    Christiansen, Mads Brøkner; Schøler, Mikkel; Balslev, Søren


    techniques, a thin film of polymer, doped with rhodamine-6G laser dye, is spin coated onto a Borofloat glass buffer substrate and shaped into a planar waveguide slab with first order DFB surface corrugations forming the laser resonator. When optically pumped at 532 nm, lasing is obtained in the wavelength...

  1. Direct transfer of wafer-scale graphene films (United States)

    Kim, Maria; Shah, Ali; Li, Changfeng; Mustonen, Petri; Susoma, Jannatul; Manoocheri, Farshid; Riikonen, Juha; Lipsanen, Harri


    Flexible electronics serve as the ubiquitous platform for the next-generation life science, environmental monitoring, display, and energy conversion applications. Outstanding multi-functional mechanical, thermal, electrical, and chemical properties of graphene combined with transparency and flexibility solidifies it as ideal for these applications. Although chemical vapor deposition (CVD) enables cost-effective fabrication of high-quality large-area graphene films, one critical bottleneck is an efficient and reproducible transfer of graphene to flexible substrates. We explore and describe a direct transfer method of 6-inch monolayer CVD graphene onto transparent and flexible substrate based on direct vapor phase deposition of conformal parylene on as-grown graphene/copper (Cu) film. The method is straightforward, scalable, cost-effective and reproducible. The transferred film showed high uniformity, lack of mechanical defects and sheet resistance for doped graphene as low as 18 Ω/sq and 96.5% transparency at 550 nm while withstanding high strain. To underline that the introduced technique is capable of delivering graphene films for next-generation flexible applications we demonstrate a wearable capacitive controller, a heater, and a self-powered triboelectric sensor.

  2. Wafer-Scale Aluminum Nanoplasmonic Resonators with Optimized Metal Deposition (United States)


    Tittl, A.; Michel , A.-K. U.; Schaferling, M.; Yin, X.; Gholipour, B.; Cui, L.; Wuttig, M.; Taubner, T.; Neubrech, F.; Giessen, H. A Switchable Mid...surface plasmon resonances in aluminum nanodisks. Nano Letters 2008, 8, 1461-1471. 41. Chu, Y.; Crozier , K. B. Experimental study of the interaction

  3. Wafer-scale characterization of carrier dynamics in graphene

    DEFF Research Database (Denmark)

    Buron, Jonas Christian Due; Petersen, Dirch Hjorth; Bøggild, Peter


    The electronic properties of single-layer graphene, such as surface conductance, carrier concentration, scattering time and mobility, can be characterized in a noncontact manner by THz time-domain spectroscopy. Standard spectroscopic imaging reveals the AC conductance over large areas with a few...... hundred μm resolution, and spectroscopic imaging on back-gated graphene allows for extraction of both the carrier concentration and the mobility. We find that spatial variations of the conductance of single-layer CVD-grown graphene are predominantly due to variations in mobility rather than in carrier...

  4. Influence of Si wafer thinning processes on (sub)surface defects (United States)

    Inoue, Fumihiro; Jourdain, Anne; Peng, Lan; Phommahaxay, Alain; De Vos, Joeri; Rebibis, Kenneth June; Miller, Andy; Sleeckx, Erik; Beyne, Eric; Uedono, Akira


    Wafer-to-wafer three-dimensional (3D) integration with minimal Si thickness can produce interacting multiple devices with significantly scaled vertical interconnections. Realizing such a thin 3D structure, however, depends critically on the surface and subsurface of the remaining backside Si after the thinning processes. The Si (sub)surface after mechanical grinding has already been characterized fruitfully for a range of few dozen of μm. Here, we expand the characterization of Si (sub)surface to 5 μm thickness after thinning process on dielectric bonded wafers. The subsurface defects and damage layer were investigated after grinding, chemical mechanical polishing (CMP), wet etching and plasma dry etching. The (sub)surface defects were characterized using transmission microscopy, atomic force microscopy, and positron annihilation spectroscopy. Although grinding provides the fastest removal rate of Si, the surface roughness was not compatible with subsequent processing. Furthermore, mechanical damage such as dislocations and amorphous Si cannot be reduced regardless of Si thickness and thin wafer handling systems. The CMP after grinding showed excellent performance to remove this grinding damage, even though the removal amount is 1 μm. For the case of Si thinning towards 5 μm using grinding and CMP, the (sub)surface is atomic scale of roughness without vacancy. For the case of grinding + dry etch, vacancy defects were detected in subsurface around 0.5-2 μm. The finished surface after wet etch remains in the nm scale in the strain region. By inserting a CMP step in between grinding and dry etch it is possible to significantly reduce not only the roughness, but also the remaining vacancies at the subsurface. The surface of grinding + CMP + dry etching gives an equivalent mono vacancy result as to that of grinding + CMP. This combination of thinning processes allows development of extremely thin 3D integration devices with minimal roughness and vacancy surface.


    Directory of Open Access Journals (Sweden)

    C. Lago Peñas


    Full Text Available



    Los objetivos de este trabajo son dos. En primer lugar estudiar los efectos que tiene disputar un partido de la Liga de Campeones sobre el resultado alcanzado por los equipos en la Liga Española en esa misma semana. En segundo lugar, verificar si la probabilidad de ganar frente a perder en la Liga Española es mayor o no para los equipos con experiencia en la Liga de Campeones frente a aquellos otros conjuntos que disputan por primera vez esta competición. La muestra consiste en 184 partidos de la Liga Española de Fútbol jugados por los equipos que se encontraban simultáneamente disputando la primera fase de la Liga de Campeones en las temporadas 2003-2004, 2004-2005 y 2005-2006. Los datos utilizados en la investigación han sido tomados de la página oficial de la Liga de Campeones, de la Liga Española y suministrados por GECA SPORT.

    De acuerdo con los resultados de la estimación de un modelo logit multinomial, disputar un partido de la Liga de Campeones durante la semana de competición no reduce la probabilidad de los equipos de ganar frente a perder en el partido de la Liga Nacional. Incluso tiene un efecto positivo para los equipos debutantes en la competición europea: cuando juegan durante la semana tienen más probabilidades de ganar en la Liga Nacional (p<0,01.

    Palabras clave: resultado, fútbol, Liga de Campeones. logit multinomial, Liga Española



    This paper has two goals. First, studying the impact of playing in the Champions League on the results in the Spanish League. Second, analyzing whether being a beginner team in the

  6. Electrical Characterization of 4H-SiC JFET Wafer: DC Parameter Variations for Extreme Temperature IC Design (United States)

    Neudeck, Philip G.; Chen, Liangyu; Spry, David J.; Beheim, Glenn M.; Chang, Carl W.


    This work reports DC electrical characterization of a 76 mm diameter 4H-SiC JFET test wafer fabricated as part of NASA's on-going efforts to realize medium-scale ICs with prolonged and stable circuit operation at temperatures as high as 500 degC. In particular, these measurements provide quantitative parameter ranges for use in JFET IC design and simulation. Larger than expected parameter variations were observed both as a function of position across the wafer as well as a function of ambient testing temperature from 23 degC to 500 degC.

  7. Soil micromorphology and the Anthropocene—Cross-scale connections and technology trends Micromorfología de suelos y el Antropoceno-Conexiones cruzadas y tendencias tecnológicas Micromorfologia dos solos e o Antropoceno-Ligaçöes à escala cruzada e tendencias tecnológicas

    Directory of Open Access Journals (Sweden)

    Curtis Monger


    Full Text Available The Anthropocene is a proposed geologic time period used to convey the profound influence humanity is having on the environmental systems of Earth. The term is controversial because of uncertainties about when to designate its beginning and whether a diagnostic feature of this era survive millions of years into the future. Still, the Anthropocene has captured the imagination of many scientists and provides a framework for analyzing the broad-scale impacts of humanity. The purpose of this paper is to explore how soil micromorphology can contribute to a deeper understanding of the Anthropocene. We approached this issue by systematically examining how data gathered at the micromorphology scale is connected to data obtained at the soil profile, landscape, and global scales. In particular we look at world food production, climate change, groundwater pollution, and plastic decomposition. From this cross-scale analysis it becomes apparent that micromorphology (1 contributes to an understanding of feedbacks operating in complex adaptive systems and (2 provides evidence otherwise invisible for making inferences about climate change. As the human footprint increases, soil micromorphology, using both traditional and emerging technologies, can make a unique contribution to understanding the Anthropocene.El Antropoceno es un periodo de tiempo geológico que se ha propuesto para explicar la gran influencia que el ser humano está teniendo en los sistemas medioambientales terrestres. Se trata de un término controvertido debido a los problemas en establecer el comienzo de este periodo y a que se desconoce si algún rasgo diagnóstico de esta era sobrevivirá en el futuro dentro de millones de años. No obstante, el Antropoceno ha llamado la atención de numerosos científicos y constituye un marco para el análisis de los impactos de la humanidad a gran escala. El objetivo de este trabajo es explorar cómo la micromorfología de suelos puede contribuir a

  8. Feature extraction of the wafer probe marks in IC packaging (United States)

    Tsai, Cheng-Yu; Lin, Chia-Te; Kao, Chen-Ting; Wang, Chau-Shing


    This paper presents an image processing approach to extract six features of the probe mark on semiconductor wafer pads. The electrical characteristics of the chip pad must be tested using a probing needle before wire-bonding to the wafer. However, this test leaves probe marks on the pad. A large probe mark area results in poor adhesion forces at the bond ball of the pad, thus leading to undesirable products. In this paper, we present a method to extract six features of the wafer probe marks in IC packaging for further digital image processing.

  9. On-wafer magnetic resonance of magnetite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Little, Charles A.E., E-mail:; Russek, Stephen E., E-mail:; Booth, James C., E-mail:; Kabos, Pavel, E-mail:; Usselman, Robert J., E-mail:


    Magnetic resonance measurements of ferumoxytol and TEMPO were made using an on-wafer transmission line technique with a vector network analyzer, allowing for broadband measurements of small sample volumes (4 nL) and small numbers of spins (1 nmol). On-wafer resonance measurements were compared with standard single-frequency cavity-based electron paramagnetic resonance (EPR) measurements using a new power conservation approach and the results show similar line shape. On-wafer magnetic resonance measurements using integrated microfluidics and microwave technology can significantly reduce the cost and sample volumes required for EPR spectral analysis and allow for integration of EPR with existing lab-on-a-chip processing and characterization techniques for point-of-care medical diagnostic applications. - Highlights: • On-wafer measurements showed similar line shape to traditional cavity-based EPR. • New power conservation approach alleviates de-embedding ambiguities. • Allows for measurements of small sample volumes and small number of spins.

  10. High Performance Wafer-Based Capillary Electrochromatography Project (United States)

    National Aeronautics and Space Administration — Los Gatos Research proposes to develop wafer-based capillary electrochromatography for lab-on-a-chip (LOC) applications. These microfluidic devices will be...

  11. Use of LigaSure™ on bile duct in rats: an experimental study. (United States)

    Marte, Antonio; Pintozzi, Lucia


    The closure of a cystic duct during cholecystectomy by means of radiofrequency is still controversial. We report our preliminary experimental results with the use of LigaSure™ on common bile duct in rats. Thirty Wistar rats weighing 70 to 120 g were employed for this study. The animals were all anesthetized with intraperitoneal ketamine and then divided into three groups. The first group (10 rats, Group C) underwent only laparotomy and isolation of the common bile duct. The second (10 rats, Group M) underwent laparotomy and closure of the common bile duct (CBD) with monopolar coagulation. The third group (10 rats, Group L) underwent laparotomy and sealing of the common bile duct with two application of LigaSureTM. Afterwards, all rats were kept in comfortable cages and were administered dibenzamine for five days. They were all sacrificed on day 20. Through a laparotomy, the liver and bile duct were removed for histological examination. Blood samples were obtained to dose bilirubin, amylase and transaminase levels. Mortality rate was 0 in the control group (C), 3/10 rats in group M and 0 in group L. In group L, the macroscopic examination showed a large choledochocele (3-3.5 × 1.5 cm) with few adhesions. At the histological examination there was optimal sealing of the common bile duct in 9/10 rats. In group M, 2/10 rats had liver abscesses, 3/10 rats had choledochocele and 5/10 rats, biliary peritonitis. There was intense tissue inflammation and the dissection was difficult. Analyses of blood samples showed an increase in total bilirubin, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in groups M and L. The preliminary results of our study confirm that radiofrequency can be safely used for the closure of the common bile duct. The choledochocele obtained with this technique could represent a good experimental model. These results could be a further step for using the LigaSureTM in clipless cholecystectomy.

  12. Ligações de montagem viga-pilar para estruturas de concreto pré-moldado: estudo de caso


    Lisiane Pereira Prado


    A pesquisa em questão é direcionada ao estudo de uma ligação provisória entre o pilar e a viga pré-moldada para que possa servir de suporte durante a execução da ligação de estrutura, que consiste na utilização de barras de aço salientes do pilar e da viga, traspassando entre si, finalizada por concreto com adição de fibras. O uso de consolo metálico formado por perfil tipo \\"U\\" e dente metálico constituído de um perfil de seção retangular vazado foi o método proposto para a ligação provisór...

  13. Automated reticle inspection data analysis for wafer fabs (United States)

    Summers, Derek; Chen, Gong; Reese, Bryan; Hutchinson, Trent; Liesching, Marcus; Ying, Hai; Dover, Russell


    To minimize potential wafer yield loss due to mask defects, most wafer fabs implement some form of reticle inspection system to monitor photomask quality in high-volume wafer manufacturing environments. Traditionally, experienced operators review reticle defects found by an inspection tool and then manually classify each defect as 'pass, warn, or fail' based on its size and location. However, in the event reticle defects are suspected of causing repeating wafer defects on a completed wafer, potential defects on all associated reticles must be manually searched on a layer-by-layer basis in an effort to identify the reticle responsible for the wafer yield loss. This 'problem reticle' search process is a very tedious and time-consuming task and may cause extended manufacturing line-down situations. Often times, Process Engineers and other team members need to manually investigate several reticle inspection reports to determine if yield loss can be tied to a specific layer. Because of the very nature of this detailed work, calculation errors may occur resulting in an incorrect root cause analysis effort. These delays waste valuable resources that could be spent working on other more productive activities. This paper examines an automated software solution for converting KLA-Tencor reticle inspection defect maps into a format compatible with KLA-Tencor's Klarity Defect(R) data analysis database. The objective is to use the graphical charting capabilities of Klarity Defect to reveal a clearer understanding of defect trends for individual reticle layers or entire mask sets. Automated analysis features include reticle defect count trend analysis and potentially stacking reticle defect maps for signature analysis against wafer inspection defect data. Other possible benefits include optimizing reticle inspection sample plans in an effort to support "lean manufacturing" initiatives for wafer fabs.

  14. Surface recombination velocity of silicon wafers by photoluminescence (United States)

    Baek, D.; Rouvimov, S.; Kim, B.; Jo, T.-C.; Schroder, D. K.


    Photoluminescence (PL) and optical reflection measurements, obtained in the two-wavelength SiPHER PL instrument, are used to determine the surface recombination velocity of silicon wafers. Local measurements and contour maps are possible allowing surface recombination maps to be displayed. This instrument also allows doping and trap density measurements. Surface recombination velocities from 10 to 106cm/s can be measured on low or high resistivity polished and epitaxial wafers.

  15. La Liga costeña de 1919, una expresión de poder regional

    Directory of Open Access Journals (Sweden)

    Eduardo Posada Carbó


    Full Text Available El 12 de enero de 1919, durante la administración conservadora de Marco Fidel Suárez, se reunió en Barranquilla la primera asamblea de la Liga Costeña, organizada por iniciativa de los periódicos de la región, con la participación de representantes de los grupos empresariales y políticos de los tres de partamentos que conformaban entonces el litoral caribeño: Atlántico, Bolívar y Magdalena.





    INTRODUCCION A comienzos del siglo XX la representación de la mujer de la clase alta chilena se vio envuelta en la convergencia entre imaginarios tradicionales y experiencias nuevas. A partir de este supuesto estudiamos la particularidad de los cambios que suscitó la modernidad en las mujeres católicas de la elite que organizaron La Liga de Damas Chilenas. A través de esta asociación, fundada en 1912, las mujeres católicas comenzaron a int...

  17. Electrochemical method for defect delineation in silicon-on-insulator wafers (United States)

    Guilinger, Terry R.; Jones, Howland D. T.; Kelly, Michael J.; Medernach, John W.; Stevenson, Joel O.; Tsao, Sylvia S.


    An electrochemical method for defect delineation in thin-film SOI or SOS wafers in which a surface of a silicon wafer is electrically connected so as to control the voltage of the surface within a specified range, the silicon wafer is then contacted with an electrolyte, and, after removing the electrolyte, defects and metal contamination in the silicon wafer are identified.

  18. Epitaxial silicon carbide on a 6″ silicon wafer (United States)

    Kukushkin, S. A.; Lukyanov, A. V.; Osipov, A. V.; Feoktistov, N. A.


    The results of the growth of silicon-carbide films on silicon wafers with a large diameter of 150 mm (6″) by using a new method of solid-phase epitaxy are presented. A SiC film growing on Si wafers was studied by means of spectral ellipsometry, SEM, X-ray diffraction, and Raman scattering. As follows from the studies, SiC layers are epitaxial over the entire surface of a 150-mm wafer. The wafers have no mechanical stresses, are smooth, and do not have bends. The half-width of the X-ray rocking curve (FWHMω- θ) of the wafers varies in the range from 0.7° to 0.8° across the thickness layer of 80-100 nm. The wafers are suitable as templates for the growth of SiC, AlN, GaN, ZnO, and other wide-gap semiconductors on its surface using standard CVD, HVPE, and MBE methods.

  19. Strategy optimization for mask rule check in wafer fab (United States)

    Yang, Chuen Huei; Lin, Shaina; Lin, Roger; Wang, Alice; Lee, Rachel; Deng, Erwin


    Photolithography process is getting more and more sophisticated for wafer production following Moore's law. Therefore, for wafer fab, consolidated and close cooperation with mask house is a key to achieve silicon wafer success. However, generally speaking, it is not easy to preserve such partnership because many engineering efforts and frequent communication are indispensable. The inattentive connection is obvious in mask rule check (MRC). Mask houses will do their own MRC at job deck stage, but the checking is only for identification of mask process limitation including writing, etching, inspection, metrology, etc. No further checking in terms of wafer process concerned mask data errors will be implemented after data files of whole mask are composed in mask house. There are still many potential data errors even post-OPC verification has been done for main circuits. What mentioned here are the kinds of errors which will only occur as main circuits combined with frame and dummy patterns to form whole reticle. Therefore, strategy optimization is on-going in UMC to evaluate MRC especially for wafer fab concerned errors. The prerequisite is that no impact on mask delivery cycle time even adding this extra checking. A full-mask checking based on job deck in gds or oasis format is necessary in order to secure acceptable run time. Form of the summarized error report generated by this checking is also crucial because user friendly interface will shorten engineers' judgment time to release mask for writing. This paper will survey the key factors of MRC in wafer fab.

  20. Influence of Si wafer thinning processes on (sub)surface defects

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Fumihiro, E-mail: [Imec, Kapeldreef 75, 3001 Leuven (Belgium); Jourdain, Anne; Peng, Lan; Phommahaxay, Alain; De Vos, Joeri; Rebibis, Kenneth June; Miller, Andy; Sleeckx, Erik; Beyne, Eric [Imec, Kapeldreef 75, 3001 Leuven (Belgium); Uedono, Akira [Division of Applied Physics, Faculty of Pure and Applied Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)


    Highlights: • Mono-vacancy free Si-thinning can be accomplished by combining several thinning techniques. • The grinding damage needs to be removed prior to dry etching, otherwise vacancies remain in the Si at a depth around 0.5 to 2 μm after Si wafer thickness below 5 μm. • The surface of grinding + CMP + dry etching is equivalent mono vacancy level as that of grinding + CMP. - Abstract: Wafer-to-wafer three-dimensional (3D) integration with minimal Si thickness can produce interacting multiple devices with significantly scaled vertical interconnections. Realizing such a thin 3D structure, however, depends critically on the surface and subsurface of the remaining backside Si after the thinning processes. The Si (sub)surface after mechanical grinding has already been characterized fruitfully for a range of few dozen of μm. Here, we expand the characterization of Si (sub)surface to 5 μm thickness after thinning process on dielectric bonded wafers. The subsurface defects and damage layer were investigated after grinding, chemical mechanical polishing (CMP), wet etching and plasma dry etching. The (sub)surface defects were characterized using transmission microscopy, atomic force microscopy, and positron annihilation spectroscopy. Although grinding provides the fastest removal rate of Si, the surface roughness was not compatible with subsequent processing. Furthermore, mechanical damage such as dislocations and amorphous Si cannot be reduced regardless of Si thickness and thin wafer handling systems. The CMP after grinding showed excellent performance to remove this grinding damage, even though the removal amount is 1 μm. For the case of Si thinning towards 5 μm using grinding and CMP, the (sub)surface is atomic scale of roughness without vacancy. For the case of grinding + dry etch, vacancy defects were detected in subsurface around 0.5–2 μm. The finished surface after wet etch remains in the nm scale in the strain region. By inserting a CMP step in

  1. Žmonių, sergančių Parkinsono liga, depresijos lygio ir socialinių ryšių sąsajos


    Dražbaitė, Indrė


    Tyrimo objektas: Žmonių, sergančių Parkinsono liga, depresijos lygis ir socialinių ryšių sąsajos. Raktiniai žodžiai: Parkinsono liga, depresija, socialiniai ryšiai. Tyrimo tikslas - ištirti žmonių sergančių Parkinsono liga depresijos lygio ir socialinių ryšių sąsajas. Uždaviniai: 1. Nustatyti žmonių, sergančių Parkinsono liga socialinių ryšių ypatumus. 2. Ištirti žmonių, sergančių Parkinsono liga depresijos atskirus komponentus ir bendrą depresijos lygį. 3. Nustatyti, žmon...

  2. Wafer current measurement for process monitoring (United States)

    Shur, Dmitry; Kadyshevitch, Alexander; Zelenko, Jeremy; Mata, Carlos; Verdugo, Victor; Guittet, Pierre-Yves; Starr, Brian; Duncan, Craig; Ventola, Stefano; Klinger, Jan


    Wafer Current Measurement (WCM) is an emerging technique for in-line process monitoring. A joint development project (JDP) has been conducted by Infineon Technologies and Applied Ma-terials (Process Diagnostics and Control Group). The main goal of this project was development of applications for the WCM technique in production environment and specifically for state of the art DRAM Infineon process. A new generation of SEM review tool with integrated FIB (Ap-plied SEMVision G2 FIB Defect Analysis system) was used for this work. A challenging layer approached in this work was the DTMO (Deep Trench Mask Open) which serves as a hard mask for subsequent deep trench (DT) capacitor formation in a silicon substrate. The aspect ratio of the openings in the DTMO layer can be as high as 20:1. As a result of the aggressive aspect ra-tio and sub-100 nm CDs the only available techniques for evaluating DTMO etch integrity (pos-sible under-etch and/or bottom CD variation) are destructive analysis methods. As a result of the extensive JDP, crucial yield limiting problems such as dielectric or/and stop layer under-etch as well as bottom CD violation have been revealed by the WCM in-line rather than by cross-sectioning in failure analysis laboratory or other destructive means. Besides, on the basis of bottom CD sensitivity of the WCM technique, etch chamber qualification (including matching and adjustment) feasibility was conducted. The motivation behind this is that chamber qualification is essential to shorten cycle time. In production environment the WCM technique is targeted for two basic applications: process monitoring including excursion control and early etch process drift warning and in-line etch chamber qualification. WCM "pilot" has been performed in production after DTMO for four novel DRAM products with CD down to 70 nm.

  3. Wafer-level micro-optics: trends in manufacturing, testing, packaging, and applications (United States)

    Voelkel, Reinhard; Gong, Li; Rieck, Juergen; Zheng, Alan


    Micro-optics is an indispensable key enabling technology (KET) for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the last decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks (supercomputer, ROADM), bringing high-speed internet to our homes (FTTH). Even our modern smart phones contain a variety of micro-optical elements. For example, LED flashlight shaping elements, the secondary camera, and ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by semiconductor industry. Thousands of components are fabricated in parallel on a wafer. We report on the state of the art in wafer-based manufacturing, testing, packaging and present examples and applications for micro-optical components and systems.

  4. Monitoring Dielectric Thin-Film Production on Product Wafers Using Infrared Emission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)



    Monitoring of dielectric thin-film production in the microelectronics industry is generally accomplished by depositing a representative film on a monitor wafer and determining the film properties off line. One of the most important dielectric thin films in the manufacture of integrated circuits is borophosphosilicate glass (BPSG). The critical properties of BPSG thin films are the boron content, phosphorus content and film thickness. We have completed an experimental study that demonstrates that infrared emission spectroscopy coupled with multivariate analysis can be used to simultaneous y determine these properties directly from the spectra of product wafers, thus eliminating the need of producing monitor wafers. In addition, infrared emission data can be used to simultaneously determine the film temperature, which is an important film production parameter. The infrared data required to make these determinations can be collected on a time scale that is much faster than the film deposition time, hence infrared emission is an ideal candidate for an in-situ process monitor for dielectric thin-film production.

  5. Three-Dimensional Wafer Stacking Using Cu TSV Integrated with 45 nm High Performance SOI-CMOS Embedded DRAM Technology

    Directory of Open Access Journals (Sweden)

    Pooja Batra


    Full Text Available For high-volume production of 3D-stacked chips with through-silicon-vias (TSVs, wafer-scale bonding offers lower production cost compared with bump bond technology and is promising for interconnect pitches smaller than 5 µ using available tooling. Prior work has presented wafer-scale integration with tungsten TSV for low-power applications. This paper reports the first use of low-temperature oxide bonding and copper TSV to stack high performance cache cores manufactured in 45 nm Silicon On Insulator-Complementary Metal Oxide Semiconductor (SOI-CMOS embedded DRAM (EDRAM having 12 to 13 copper wiring levels per strata and upto 11000 TSVs at 13 µm pitch for power and signal delivery. The wafers are thinned to 13 µm using grind polish and etch. TSVs are defined post bonding and thinning using conventional alignment techniques. Up to four additional metal levels are formed post bonding and TSV definition. A key feature of this process is its compatibility with the existing high performance POWER7™ EDRAM core requiring neither modification of the existing CMOS fabrication process nor re-design since the TSV RC characteristic is similar to typical 100–200 µm length wiring load enabling 3D macro-to-macro signaling without additional buffering Hardware measurements show no significant impact on device drive and off-current. Functional test at wafer level confirms 2.1 GHz 3D stacked EDRAM operation.

  6. ILT based defect simulation of inspection images accurately predicts mask defect printability on wafer (United States)

    Deep, Prakash; Paninjath, Sankaranarayanan; Pereira, Mark; Buck, Peter


    At advanced technology nodes mask complexity has been increased because of large-scale use of resolution enhancement technologies (RET) which includes Optical Proximity Correction (OPC), Inverse Lithography Technology (ILT) and Source Mask Optimization (SMO). The number of defects detected during inspection of such mask increased drastically and differentiation of critical and non-critical defects are more challenging, complex and time consuming. Because of significant defectivity of EUVL masks and non-availability of actinic inspection, it is important and also challenging to predict the criticality of defects for printability on wafer. This is one of the significant barriers for the adoption of EUVL for semiconductor manufacturing. Techniques to decide criticality of defects from images captured using non actinic inspection images is desired till actinic inspection is not available. High resolution inspection of photomask images detects many defects which are used for process and mask qualification. Repairing all defects is not practical and probably not required, however it's imperative to know which defects are severe enough to impact wafer before repair. Additionally, wafer printability check is always desired after repairing a defect. AIMSTM review is the industry standard for this, however doing AIMSTM review for all defects is expensive and very time consuming. Fast, accurate and an economical mechanism is desired which can predict defect printability on wafer accurately and quickly from images captured using high resolution inspection machine. Predicting defect printability from such images is challenging due to the fact that the high resolution images do not correlate with actual mask contours. The challenge is increased due to use of different optical condition during inspection other than actual scanner condition, and defects found in such images do not have correlation with actual impact on wafer. Our automated defect simulation tool predicts

  7. Fuzzy TOPSIS for Multiresponse Quality Problems in Wafer Fabrication Processes

    Directory of Open Access Journals (Sweden)

    Chiun-Ming Liu


    Full Text Available The quality characteristics in the wafer fabrication process are diverse, variable, and fuzzy in nature. How to effectively deal with multiresponse quality problems in the wafer fabrication process is a challenging task. In this study, the fuzzy technique for order preference by similarity to an ideal solution (TOPSIS, one of the fuzzy multiattribute decision-analysis (MADA methods, is proposed to investigate the fuzzy multiresponse quality problem in integrated-circuit (IC wafer fabrication process. The fuzzy TOPSIS is one of the effective fuzzy MADA methods for dealing with decision-making problems under uncertain environments. First, a fuzzy TOPSIS methodology is developed by considering the ambiguity between quality characteristics. Then, a detailed procedure for the developed fuzzy TOPSIS approach is presented to show how the fuzzy wafer fabrication quality problems can be solved. Real-world data is collected from an IC semiconductor company and the developed fuzzy TOPSIS approach is applied to find an optimal combination of parameters. Results of this study show that the developed approach provides a satisfactory solution to the wafer fabrication multiresponse problem. This developed approach can be also applied to other industries for investigating multiple quality characteristics problems.

  8. Comparison of the safety of electrotome, Harmonic scalpel, and LigaSure for management of thyroid surgery. (United States)

    Yang, Xiaodong; Cao, Jian; Yan, Yichao; Liu, Fangfang; Li, Tao; Han, Long; Ye, Chunxiang; Zheng, Shuying; Wang, Shan; Ye, Yingjiang; Jiang, Kewei


    Energy-based surgical devices, including electrotome, the Harmonic scalpel, and LigaSure, have been widely applied in thyroid surgery, although a comparison of their safety and efficacy has not been reported yet. In this study, we investigated the feasibility of using hemostatic energy-based surgical devices during thyroid surgery in a canine model. Twenty-four beagle dogs were randomly divided into the following groups: electrotome (30 kW), electrotome (15 kW), the Harmonic scalpel (output level 3), and LigaSure (middle gear). The hemostatic devices were applied on the thyroid surface for 3 seconds and then near the recurrent laryngeal nerve (RLN; distance of 5 mm, 3 mm, or 1 mm) for 3 seconds. Evoked electromyography (EMG) amplitudes were recorded by intraoperative neuromonitoring (IONM). Acute microstructural morphological damage to thyroid tissues and the RLN were evaluated immediately after the procedure by light and electron microscopy. Electrotome caused a significant decrease in evoked EMG amplitudes when applied at a vertical distance of 1 mm from the RLN, both at 30 kW (1046 ± 404.3 μV vs 153 ± 245.5 μV; p Harmonic scalpel and LigaSure induced neither marked changes in evoked EMG amplitudes when applied at vertical distances of 5 mm, 3 mm, or 1 mm (all p > .05) nor microstructural morphological changes in the RLNs. The electrotome (15 kW) caused more serious thermal damage to thyroid tissues than that caused by either the Harmonic scalpel or LigaSure (thermal damaged depth: 0.951 ± 0.061 vs 0.756 ± 0.074, p Harmonic scalpel and LigaSure groups (p = .435). LigaSure and the Harmonic scalpel might be safer than electrotome when used in thyroid operations. LigaSure generates less heat than the Harmonic scalpel and electrotome. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1078-1085, 2017. © 2017 Wiley Periodicals, Inc.

  9. Wafer Fusion for Integration of Semiconductor Materials and Devices

    Energy Technology Data Exchange (ETDEWEB)

    Choquette, K.D.; Geib, K.M.; Hou, H.Q.; Allerman, A.A.; Kravitz, S.; Follstaedt, D.M.; Hindi, J.J.


    We have developed a wafer fusion technology to achieve integration of semiconductor materials and heterostructures with widely disparate lattice parameters, electronic properties, and/or optical properties for novel devices not now possible on any one substrate. Using our simple fusion process which uses low temperature (400-600 C) anneals in inert N{sub 2} gas, we have extended the scope of this technology to examine hybrid integration of dissimilar device technologies. As a specific example, we demonstrate wafer bonding vertical cavity surface emitting lasers (VCSELs) to transparent AlGaAs and GaP substrates to fabricate bottom-emitting short wavelength VCSELs. As a baseline fabrication technology applicable to many semiconductor systems, wafer fusion will revolutionize the way we think about possible semiconductor devices, and enable novel device configurations not possible by epitaxial growth.

  10. UV-LIGA technique for ECF micropumps using back UV exposure and self-alignment (United States)

    Han, D.; Xia, Y.; Yokota, S.; Kim, J. W.


    This paper proposes and develops a novel UV-LIGA technique using back UV exposure and self-alignment to realize high aspect ratio micromachining (HARM) in high power density electro-conjugate fluid (ECF) micropumps. ECF is a functional fluid designed to be able to generate strong and active jet flow (ECF jetting) between anode and cathode in ECF when high DC voltage is applied. We have developed high power density ECF micropumps consisting of triangular prism and slit electrode pairs (TPSEs) fabricated by HARM. The traditional UV-LIGA technique for HARM is mainly divided into two approaches: (a) single thick layer and (b) multiple thin layers. Both methods have limitations—deformed molds in the former and misalignment between layers in the latter. Using the finite element method software COMSOL Multiphysics, we demonstrate that the deformed micro-molds critically impair the performance of ECF micropumps. In addition, we experimentally prove that the misalignment would easily trigger electric discharge in the ECF micropumps. To overcome these limitations, we conceive a new concept utilizing the seed electrode layer for electroforming as the UV shield and pattern photoresist (KMPR) by back UV exposure. The seed electrode layer should be composed of a non-transparent conductor (Au/Ti) for patterning and a transparent conductor (ITO) for wiring. Instead of ITO, we propose the concept of transparency-like electrodes comprised of thin metal line patterns. To verify this concept, KMPR layers with thicknesses of 70, 220, and 500 µm are experimentally investigated. In the case of 500 µm KMPR thickness, the concept of transparency-like electrode was partially proved. As a result, TPSEs with a height of 440 µm were successfully fabricated. Characteristic experiments demonstrated that ECF micropumps (367 mW cm‑3) fabricated by back UV achieved almost the same output power density as ECF micropumps (391 mW cm‑3) fabricated by front UV. This paper proves that the

  11. High performance few-layer MoS2 transistor arrays with wafer level homogeneity integrated by atomic layer deposition (United States)

    Zhang, Tianbao; Wang, Yang; Xu, Jing; Chen, Lin; Zhu, Hao; Sun, Qingqing; Ding, Shijin; Zhang, David Wei


    Wafer-level integration of 2D transition metal disulfide is the key factor for future large-scale integration of the continuously scaling-down devices, and has attracted great attention in recent years. Compared with other ultra-thin film growth methods, atomic layer deposition (ALD) has the advantages of excellent step coverage, uniformity and thickness controllability. In this work, we synthesized large-scale and thickness-controllable MoS2 films on sapphire substrate by ALD at 150 °C with molybdenum hexcarbonyl and hexamethyldisilathiane (HMDST) as precursors followed by high-temperature annealing in sulfur atmosphere. HMDST is introduced for the first time to enable a toxic-free process without hazardous sulfur precursors such as H2S and CH3SSCH3. The synthesized MoS2 retains the inherent benefits from the ALD process, including thickness controllability, reproducibility, wafer-level thickness uniformity, and high conformity. Finally, field-effect transistor (FET) arrays were fabricated based on the large-area ALD MoS2 films. The top-gate FETs exhibited excellent electrical performance such as high on/off current ratio over 103 and peak room-temperature mobility up to 11.56 cm2 V‑1 s‑1. This work opens up an attractive approach to realize the application of high-quality 2D materials with wafer scale homogeneity.

  12. Fabrication of light-guiding devices and fiber-coupling structures by the LIGA process (United States)

    Rogner, Arnd; Ehrfeld, Wolfgang


    The LIGA process which is based on deep-etch lithography in combination with high-precision electroforming and moulding processes is a particularly promising method for the fabrication of three-dimensional microstructures. Some interesting applications can be seen in the field of integrated optics. Passive waveguide structures can be fabricated by deep-etch synchrotron radiation lithography of multilayer resist systems. Using this technique, multimode strip waveguides with a PMMA core and a P (TFPMA/MMA) cladding as well as a planar grating spectrograph have been realized. The attenuation of 0.18 dB/cm measured at a wavelength of 850 nm can be reduced, especially in the near IR-region, by the use of deuterated PMMA as a core material. For plastic fiber LAN applications, moulding processes for the replication of passive multimode waveguide components like Y-couplers or star couplers are under investigation. The advantages of the LIGA process--unrestricted design in the cross-sectional shape and a small surface roughness in the range of 10 - 20 nm--are of special interest for these developments. For coupling fibers to integrated-optical chips, structures of a coupling array have been fabricated. The fibers are guided by exactly positioned stop faces and then precisely located and prefixed by integrated spring elements. The main advantages are as follows: the thermal expansion coefficient of the array can be matched to the optical chip material, the use of spring elements for prefixing simplifies the handling, and adhesives and the connected problems can be avoided.

  13. Electromechanically driven microchopper for integration in microspectrometers based on LIGA technology (United States)

    Krippner, Peter; Mohr, Juergen; Saile, Volker


    In recent years, microspectrometers made by the LIGA technology for the visible wavelength range have found their way into the market. Opening the wide field of spectral analysis in the infrared range, the concept of a highly transmissive hollow waveguide has been demonstrated successfully. In combination with linear detector arrays, hollow waveguide microspectrometers can be combined into handheld infrared spectrometer systems. The only obstacle to a miniaturized system is the lack of miniaturized light modulators. To solve this problem, a miniaturized light modulator has been developed. It consists of an oscillating stop driven by an electromagnetic actuator. It is made out of permalloy by means of LIGA micromechanics. Its outer dimensions of approx. 3.0 X 3.2 mm2 and a structure height of 280 micrometer allow it to be integrated into the plane of the entrance slit of the microspectrometer of about 20 mm to 30 mm size. The spectrometer has alignment structures to ensure positioning of the oscillating stop close to the entrance slit. This simplifies assembly. The actuator is excited by an hybrid integrated coil fixed by springs snapping into place during assembly. The maximum supply voltage of 5V allows the chopper to be used in low-voltage spectrometer systems, especially in handheld systems. The highest modulation frequency is more than 1 kHz, which is sufficient to work with the lead salt detectors commonly used. In this frequency range, detector noise is greatly attenuated compared to continuous-light operation. The paper contains an outline of the concept of the whole microspectrometer system. Experimental results are discussed to demonstrate the performance of the system.

  14. La Liga Comunista 23 de Septiembre en Sinaloa. Los restos de un naufragio: 1974-1976

    Directory of Open Access Journals (Sweden)

    Sergio Arturo Sánchez Parra


    Full Text Available El presente artículo trata sobre algunas de las principales características que adoptó el denominado “periodo gris”, etapa de la vida de la principal organización político militar de tipo urbano del México de los años setenta del siglo XX y la entidad federativa Sinaloa, ubicada en el noroeste del territorio nacional. Esta fase, se distinguió por la pérdida del “dirigente histórico” de la Liga Comunista 23 de Septiembre (LC23S, el arribo a la conducción del grupo armado de un liderazgo caracterizado por el militarismo extremo, la búsqueda de la confrontación y la derrota político y militar frente al Estado y sus fuerzas de seguridad. Destacamos en el documento tres rubros a nuestro parecer que delinean una etapa que trascendió los años aquí analizados, a las escisiones internas que operaron al seno del grupo armado, entre quienes abandonaron por diversas circunstancias la lucha revolucionaria y los que decidieron continuarla tanto a nivel nacional como en la entidad sinaloense, b la estrategia política y militar que el Estado mexicano estableció para confrontar a esta y otras insurgencias armadas, c el cariz que adoptó la violencia guerrillera en un ambiente de franco fracaso militar y sobre todo político y d las producciones discursivas que se elaboraron a pesar del ambiente de descalabro privativo en que había caído la organización clandestina. A su vez, este texto aborda las diferentes causas-nacionales y regionales-que contribuyeron a la derrota militar y sobre todo política de la Liga y su proyecto de transformación revolucionaria de la sociedad.

  15. Friction mechanisms of silicon wafer and silicon wafer coated with diamond-like carbon film and two monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Singh, R. Arvind; Yoon, Eui Sung; Han, Hung Gu; Kong, Ho Sung [Korea Institute of Science and Technology, Seoul (Korea, Republic of)


    The friction behaviour of Si-wafer, Diamond-Like Carbon (DLC) and two Self-Assembled Monolayers(SAMs) namely DiMethylDiChlorosilane (DMDC) and DiPhenyl-DiChlorosilane (DPDC) coated on Si-wafer was studied under loading conditions in milli-Newton (mN) range. Experiments were performed using a ball-on-flat type reciprocating micro-tribo tester. Glass balls with various radii 0.25 mm, 0.5 mm and 1 mm were used. The applied normal load was in the range of 1.5 mN to 4.8 mN. Results showed that the friction increased with the applied normal load in the case of all the test materials. It was also observed that friction was affected by the ball size. Friction increased with the increase in the ball size in the case of Si-wafer. The SAMs also showed a similar trend, but had lower values of friction than those of Si-wafer. Interestingly, for DLC it was observed that friction decreased with the increase in the ball size. This distinct difference in the behavior of friction in DLC was attributed to the difference in the operating mechanism. It was observed that Si-wafer and DLC exhibited wear, whereas wear was absent in the SAMs. Observations showed that solid-solid adhesion was dominant in Si-wafer, while plowing in DLC. The wear in these two materials significantly influenced their friction. In the case of SAMs their friction behaviour was largely influenced by the nature of their molecular chains.

  16. Fusion bonding of Si wafers investigated by x ray diffraction

    DEFF Research Database (Denmark)

    Weichel, Steen; Grey, Francois; Rasmussen, Kurt


    The interface structure of bonded Si(001) wafers with twist angle 6.5 degrees is studied as a function of annealing temperature. An ordered structure is observed in x-ray diffraction by monitoring a satellite reflection due to the periodic modulation near the interface, which results from...

  17. Scatterometry on pelliclized masks: an option for wafer fabs (United States)

    Gallagher, Emily; Benson, Craig; Higuchi, Masaru; Okumoto, Yasuhiro; Kwon, Michael; Yedur, Sanjay; Li, Shifang; Lee, Sangbong; Tabet, Milad


    Optical scatterometry-based metrology is now widely used in wafer fabs for lithography, etch, and CMP applications. This acceptance of a new metrology method occurred despite the abundance of wellestablished CD-SEM and AFM methods. It was driven by the desire to make measurements faster and with a lower cost of ownership. Over the last year, scatterometry has also been introduced in advanced mask shops for mask measurements. Binary and phase shift masks have been successfully measured at all desired points during photomask production before the pellicle is mounted. There is a significant benefit to measuring masks with the pellicle in place. From the wafer fab's perspective, through-pellicle metrology would verify mask effects on the same features that are characterized on wafer. On-site mask verification would enable quality control and trouble-shooting without returning the mask to a mask house. Another potential application is monitoring changes to mask films once the mask has been delivered to the fab (haze, oxide growth, etc.). Similar opportunities apply to the mask metrologist receiving line returns from a wafer fab. The ability to make line-return measurements without risking defect introduction is clearly attractive. This paper will evaluate the feasibility of collecting scatterometry data on pelliclized masks. We explore the effects of several different pellicle types on scatterometry measurements made with broadband light in the range of 320-780 nm. The complexity introduced by the pellicles' optical behavior will be studied.

  18. High frequency guided wave propagation in monocrystalline silicon wafers (United States)

    Pizzolato, Marco; Masserey, Bernard; Robyr, Jean-Luc; Fromme, Paul


    Monocrystalline silicon wafers are widely used in the photovoltaic industry for solar panels with high conversion efficiency. The cutting process can introduce micro-cracks in the thin wafers and lead to varying thickness. High frequency guided ultrasonic waves are considered for the structural monitoring of the wafers. The anisotropy of the monocrystalline silicon leads to variations of the wave characteristics, depending on the propagation direction relative to the crystal orientation. Full three-dimensional Finite Element simulations of the guided wave propagation were conducted to visualize and quantify these effects for a line source. The phase velocity (slowness) and skew angle of the two fundamental Lamb wave modes (first anti-symmetric mode A0 and first symmetric mode S0) for varying propagation directions relative to the crystal orientation were measured experimentally. Selective mode excitation was achieved using a contact piezoelectric transducer with a custom-made wedge and holder to achieve a controlled contact pressure. The out-of-plane component of the guided wave propagation was measured using a noncontact laser interferometer. Good agreement was found with the simulation results and theoretical predictions based on nominal material properties of the silicon wafer.

  19. development and evaluation of lyophilized thiolated-chitosan wafers

    African Journals Online (AJOL)


    creased ease of hydration, improved in vitro mucoadhesive characteristics and enhanced BSA release, without affecting the conformational stability of the protein due to the presence of a cryoprotectant. These results show the potential application of annealed freeze-dried thiolated- chitosan wafers for buccal mucosa ...

  20. The Surface adhesion parameter: A measure for wafer bondability

    NARCIS (Netherlands)

    Gui, C.; Elwenspoek, Michael Curt; Tas, Niels Roelof; Gardeniers, Johannes G.E.


    A theory is presented which describes the initial direct wafer bonding process. The effect of surface microroughness on the bondability is studied on the basis of the theory of contact and adhesion of elastic solids. An effective bonding energy, the maximum of which is the specific surface energy of

  1. National solar technology roadmap: Wafer-silicon PV

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, Bhushan [National Renewable Energy Lab. (NREL), Golden, CO (United States)


    This report applies to all bulk-silicon-based PV technologies, including those based on Czochralski, multicrystalline, float-zone wafers, and melt-grown crystals that are 100 μm or thicker, such as ribbons, sheet, or spheral silicon.

  2. Sacrificial wafer bonding for planarization after very deep etching

    NARCIS (Netherlands)

    Spiering, V.L.; Spiering, Vincent L.; Berenschot, Johan W.; Elwenspoek, Michael Curt; Fluitman, J.H.J.

    A new technique is presented that provides planarization after a very deep etching step in silicon. This offers the possibility for as well resist spinning and layer patterning as realization of bridges or cantilevers across deep holes or grooves. The sacrificial wafer bonding technique contains a

  3. Chemical processing of materials on silicon: more functionality, smaller features, and larger wafers. (United States)

    Marchack, Nathan; Chang, Jane P


    The invention of the transistor followed by more than 60 years of aggressive device scaling and process integration has enabled the global information web and subsequently transformed how people communicate and interact. The principles and practices built upon chemical processing of materials on silicon have been widely adapted and applied to other equally important areas, such as microfluidic systems for chemical and biological analysis and microscale energy storage solutions. The challenge of continuing these technological advances hinges on further improving the performance of individual devices and their interconnectivity while making the manufacturing processes economical, which is dictated by the materials' innate functionality and how they are chemically processed. In this review, we highlight challenges in scaling up the silicon wafers and scaling down the individual devices as well as focus on needs and challenges in the synthesis and integration of multifunctional materials.

  4. Efeitos da adição de níquel em ligas ferro-cromo. Parte I: propriedades mecânicas


    Bubani, Franco de Castro; Decarli, Célia Cristina Moretti; Marques, Daniel Cirillo; Barbosa, Celso Antonio; Diniz, Anselmo Eduardo; Mei, Paulo Roberto


    O objetivo desse trabalho é estudar a influência de adições de níquel sobre as propriedades mecânicas de ligas Fe-Cr. Para atender a esse propósito, foram preparadas diversas ligas com a composição básica 18%Cr - 0,01%C - 0,2%Si - 0,4%Mn, variando-se o teor de níquel (0, 10, 20, 40 e 60 % em peso). A caracterização das ligas foi feita por difração de raios X e análise térmica. Foi determinada a dureza das ligas no estado como recebido e após a imposição de deformação a frio. Foram realizados ...

  5. Processamento de Ligas de Níquel com Técnica de Manufatura Aditiva Utilizando Plasma por Arco Transferido

    Directory of Open Access Journals (Sweden)

    Eduardo André Alberti


    Full Text Available ResumoA manufatura aditiva é um processo utilizado para a construção e reparos de peças que possuem geometria complexa ou que necessitem de gradiente de propriedades. Nessa técnica múltiplas camadas são depositadas para a construção da geometria do componente. O sucesso desse procedimento depende de fatores como a técnica de deposição, parâmetros, liga a ser depositada e condições da deposição, como temperatura e atmosfera protetora. Neste estudo, o potencial da técnica de Plasma por arco transferido para manufatura aditiva foi avaliado produzindo “paredes finas”, construídas a partir da sobreposição de cordões. Foram utilizadas duas ligas a base de níquel, uma endurecida por precipitação e outra endurecida por solução sólida. Durante os trabalhos, foram selecionados os parâmetros de processamentos, incluindo a avaliação do efeito do pré-aquecimento a 300°C. Resultados mostraram que a composição química da liga influencia a geometria da parede construída assim como a utilização de pré-aquecimento. Estruturas de solidificação exibindo dendritas refinadas com crescimento epitaxial entre camadas são identificadas. Entretanto, as características da liga determinam o perfil de dureza ao longo da seção transversal, sendo a liga endurecida por precipitação influenciada pelos ciclos térmicos de deposição e a liga endurecida por solução sólida pela diluição com o substrato. Em qualquer dos casos é recomendado a aplicação de tratamento térmico pós-soldagem para uniformização das propriedades.

  6. Bulk Laser Material Modification: Towards a Kerfless Laser Wafering Process (United States)

    LeBeau, James

    Due to the ever increasing relevance of finer machining control as well as necessary reduction in material waste by large area semiconductor device manufacturers, a novel bulk laser machining method was investigated. Because the cost of silicon and sapphire substrates are limiting to the reduction in cost of devices in both the light emitting diode (LED) and solar industries, and the present substrate wafering process results in >50% waste, the need for an improved ingot wafering technique exists. The focus of this work is the design and understanding of a novel semiconductor wafering technique that utilizes the nonlinear absorption properties of band-gapped materials to achieve bulk (subsurface) morphological changes in matter using highly focused laser light. A method and tool was designed and developed to form controlled damage regions in the bulk of a crystalline sapphire wafer leaving the surfaces unaltered. The controllability of the subsurface damage geometry was investigated, and the effect of numerical aperture of the focusing optic, energy per pulse, wavelength, and number of pulses was characterized for a nanosecond pulse length variable wavelength Nd:YAG OPO laser. A novel model was developed to describe the geometry of laser induced morphological changes in the bulk of semiconducting materials for nanosecond pulse lengths. The beam propagation aspect of the model was based on ray-optics, and the full Keldysh multiphoton photoionization theory in conjuncture with Thornber's and Drude's models for impact ionization were used to describe high fluence laser light absorption and carrier generation ultimately resulting in permanent material modification though strong electron-plasma absorption and plasma melting. Although the electron-plasma description of laser damage formation is usually reserved for extremely short laser pulses (plane of damage in the bulk of sapphire wafers. This was accomplished using high numerical aperture optics, a variable

  7. An electron-multiplying ''Micromegas'' grid made in silicon wafer post-processing technology

    NARCIS (Netherlands)

    Chefdeville, M.A.; Colas, P.; Giomataris, Y.; van der Graaf, H.; Heijne, E.H.M.; van der Putten, S.; Salm, Cora; Schmitz, Jurriaan; Smits, Sander M.; Timmermans, J.; Timmermans, J.; Visschers, J.L.


    A technology for manufacturing an aluminium grid onto a silicon wafer has been developed. The grid is fixed parallel and precisely to the wafer (anode) surface at a distance of 50 mm by means of insulating pillars. When some 400V are applied between the grid and (anode) wafer, gas multiplication

  8. An electron-multiplying 'Micromegas' grid made in silicon wafer post-processing technology

    NARCIS (Netherlands)

    Chefdeville, M.; Chefdeville, M.A.; Colas, P.; Giomataris, Y.; van der Graaf, H.; Heijne, E.H.M.; van der Putten, S.; Salm, Cora; Schmitz, Jurriaan; Smits, Sander M.; Timmermans, J.; Visschers, J.L.

    A technology for manufacturing an aluminium grid onto a silicon wafer has been developed. The grid is fixed parallel and precisely to the wafer (anode) surface at a distance of 50 μm by means of insulating pillars. When some 400 V are applied between the grid and (anode) wafer, gas multiplication

  9. 450 mm Silicon Wafers Are Imperative for Moore's Law but maybe Postponed

    National Research Council Canada - National Science Library

    Tu, Hailing


    ... of the adequate approaches is to introduce 450 mm silicon wafers for 10 nm techno-logy node and beyond. Mr. Moore saw wafers growing, as early as in 1965, ever large as a way to keep the device cost down. Historically, each wafer size transition has been technically more challenging as complexity increases. The lesson learned from 300 mm silico...

  10. Mapping strain fields in ultrathin bonded Si wafers by x-ray scattering

    DEFF Research Database (Denmark)

    Nielsen, Mourits; Poulsen, Mette; Bunk, Oliver


    X-ray scattering reveals the atomic displacements arising from rotational misalignment in ultrathin silicon bonded wafers. For a 4.3 nm top wafer, the strain field penetrates from the bonded interface to the surface and produces distinctive finite-size oscillations in x-ray data. Analytical...... calculations permit the atomic displacements throughout the thin top wafer to be modeled....

  11. Concepções alternativas dos alunos sobre ligação metálica


    Ferreira, I. da M.


    Nesse estudo investigou-se as concepções alternativas de alunos de uma disciplina do curso de licenciatura em química sobre a temática ligação metálica. A investigação foi realizada através da aplicação de um questionário que envolveu aspectos microscópico, macroscópico e representacional do conhecimento químico sobre ligação metálica. Os resultados obtidos mostraram que os alunos apresentaram ideias diferentes daquelas aceitas pela comunidade científica e algumas dessas ideias foram similare...

  12. Fabrication of Ge-on-insulator wafers by Smart-CutTM with thermal management for undamaged donor Ge wafers (United States)

    Kim, Munho; Cho, Sang June; Jayeshbhai Dave, Yash; Mi, Hongyi; Mikael, Solomon; Seo, Jung-Hun; Yoon, Jung U.; Ma, Zhenqiang


    Newly engineered substrates consisting of semiconductor-on-insulator are gaining much attention as starting materials for the subsequent transfer of semiconductor nanomembranes via selective etching of the insulating layer. Germanium-on-insulator (GeOI) substrates are critically important because of the versatile applications of Ge nanomembranes (Ge NMs) toward electronic and optoelectronic devices. Among various fabrication techniques, the Smart-CutTM technique is more attractive than other methods because a high temperature annealing process can be avoided. Another advantage of Smart-CutTM is the reusability of the donor Ge wafer. However, it is very difficult to realize an undamaged Ge wafer because there exists a large mismatch in the coefficient of thermal expansion among the layers. Although an undamaged donor Ge wafer is a prerequisite for its reuse, research related to this issue has not yet been reported. Here we report the fabrication of 4-inch GeOI substrates using the direct wafer bonding and Smart-CutTM process with a low thermal budget. In addition, a thermo-mechanical simulation of GeOI was performed by COMSOL to analyze induced thermal stress in each layer of GeOI. Crack-free donor Ge wafers were obtained by annealing at 250 °C for 10 h. Raman spectroscopy and x-ray diffraction (XRD) indicated similarly favorable crystalline quality of the Ge layer in GeOI compared to that of bulk Ge. In addition, Ge p-n diodes using transferred Ge NM indicate a clear rectifying behavior with an on and off current ratio of 500 at ±1 V. This demonstration offers great promise for high performance transferrable Ge NM-based device applications.

  13. Liga NiCrSiBC: Microestrutura e Dureza de Revestimentos Processados a Arco e a Laser

    Directory of Open Access Journals (Sweden)

    Leandro J. da Silva


    Full Text Available A técnica de processamento é determinante sobre características de um revestimento. Isso porque o aporte térmico, que depende da técnica e dos parâmetros, tem influência sobre a diluição e a taxa de solidificação. Em ligas com baixa complexidade metalúrgica, o impacto do processamento com técnicas de deposição que impõem maior taxa de resfriamento podem se traduzir em refino da microestrutura. Espera-se que quanto mais refinada a microestrutura maior a resistência mecânica do revestimento. Entretanto, na deposição de ligas de maior complexidade metalúrgica isso nem sempre ocorre, porque a elevada taxa de resfriamento pode suprimir formação/precipitação de fases responsáveis pela resistência. Neste estudo, a influência do processamento sobre microestrutura e dureza de revestimentos da liga Colmonoy-6® foi avaliada. A liga foi processada por plasma com arco transferido (PTA e laser de diodo de alta potência (HPDL sobre chapas de AISI 304 com dois níveis de diluição. Em ambos os casos, revestimentos de boa qualidade e livres defeitos foram obtidos. O aumento do teor de Fe (diluição e as diferentes taxas de resfriamento decorrem do processamento com diferentes parâmetros e técnicas. Em consequência, ocorrem mudanças significativas na microestrutura e na dureza dos revestimentos que estão associadas à distribuição, morfologia e composição química dos carbonetos e, principalmente, dos boretos.

  14. Wafer-level packaging with compression-controlled seal ring bonding (United States)

    Farino, Anthony J


    A device may be provided in a sealed package by aligning a seal ring provided on a first surface of a first semiconductor wafer in opposing relationship with a seal ring that is provided on a second surface of a second semiconductor wafer and surrounds a portion of the second wafer that contains the device. Forcible movement of the first and second wafer surfaces toward one another compresses the first and second seal rings against one another. A physical barrier against the movement, other than the first and second seal rings, is provided between the first and second wafer surfaces.

  15. Material size effects on crack growth along patterned wafer-level Cu–Cu bonds

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Niordson, Christian Frithiof; Hutchinson, John W.


    the toughness peak and the subsequent plateau level are highly sensitive to the value of the characteristic material length. A small material length, relative to the thickness of the Cu film, gives high toughness whereas a length comparable to the film thickness gives much reduced crack growth resistance......The role of micron-scale patterning on the interface toughness of bonded Cu-to-Cu nanometer-scale films is analyzed, motivated by experimental studies of Tadepalli, Turner and Thompson. In the experiments 400nm Cu films were deposited in various patterns on Si wafer substrates and then bonded...... together. Crack growth along the bond interface is here studied numerically using finite element analyses. The experiments have shown that plasticity in the Cu films makes a major contribution to the macroscopic interface toughness. To account for the size dependence of the plastic flow a strain gradient...

  16. Silicon-to-silicon wafer bonding using evaporated glass

    DEFF Research Database (Denmark)

    Weichel, Steen; Reus, Roger De; Lindahl, M.


    Anodic bending of silicon to silicon 4-in. wafers using an electron-beam evaporated glass (Schott 8329) was performed successfully in air at temperatures ranging from 200 degrees C to 450 degrees C. The composition of the deposited glass is enriched in sodium as compared to the target material...... of silicon/glass structures in air around 340 degrees C for 15 min leads to stress-free structures. Bonded wafer pairs, however, show no reduction in stress and always exhibit compressive stress. The bond yield is larger than 95% for bonding temperatures around 350 degrees C and is above 80% for bonding...... from 25 N/mm(2) to 0 N/mm(2) at 200 degrees C. A weak dependence on feature size was observed. For bonding temperatures higher than 300 degrees C fracture occurs randomly in the bulk of the silicon, whereas for bonding temperatures lower than 300 degrees C fracture always occurs at the bonding...

  17. Metal adsorbent for alkaline etching aqua solutions of Si wafer (United States)

    Tamada, Masao; Ueki, Yuji; Seko, Noriaki; Takeda, Toshihide; Kawano, Shin-ichi


    High performance adsorbent is expected to be synthesized for the removal of Ni and Cu ions from strong alkaline solution used in the surface etching process of Si wafer. Fibrous adsorbent was synthesized by radiation-induce emulsion graft polymerization onto polyethylene nonwoven fabric and subsequent amination. The reaction condition was optimized using 30 L reaction vessel and nonwoven fabric, 0.3 m width and 18 m long. The resulting fibrous adsorbent was evaluated by 48 wt% NaOH and KOH contaminated with Ni and Cu ions, respectively. The concentration levels of Ni and Cu ions was reduced to less than 1 μg/kg (ppb) at the flow rate of 10 h-1 in space velocity. The life of adsorbent was 30 times higher than that of the commercialized resin. This novel adsorbent was commercialized as METOLATE® since the ability of adsorption is remarkably higher than that of commercial resin used practically in Si wafer processing.

  18. Efeito da temperatura e do teor de níquel nas propriedades mecânicas e a correlação com usinabilidade em ligas Fe-18Cr-Ni


    Bubani,Franco de Castro; Decarli,Célia Cristina Moretti; Brollo,Gabriela Lujan; Barbosa,Antonio Celso; Diniz,Anselmo Eduardo; Mei,Paulo Roberto


    Foram realizados ensaios de tração na temperatura ambiente em ligas Fe-18%Cr, com teor de níquel variando entre zero e 60% e correlacionaram-se as propriedades obtidas com os resultados de usinabilidade obtidos anteriormente pelo grupo. As ligas foram ensaiadas, também, a 350 e 700ºC, de modo a determinar suas propriedades, na faixa de temperatura alcançada, no local da usinagem. A liga ferrítica apresentou alongamento e limite de resistência menores que as ligas austeníticas, tanto à tempera...

  19. Dominant iron gettering mechanism in p/p+ silicon wafers (United States)

    Lin, Wen; Benton, J. L.; Pinacho, R.; Ramappa, D. A.; Henley, W.


    Fe gettering mechanisms in p/p+ epitaxial Si were investigated under controlled contamination and annealing cycles. The dominant Fe gettering mechanism is the Fermi level controlled coulomb attraction between Fe+ and B- in the p+ substrate of the p/p+ wafers. Oxygen precipitates do not appear to contribute when using normal cooling rates following heat treatments. The epi-substrate interfacial strain plays no role in Fe gettering.

  20. Improvement of multicrystalline silicon wafer solar cells by post ...

    Indian Academy of Sciences (India)


    (boron-doped) with ~ 3 Ω cm resistivity and having an initial thickness of 380 μm. These wafers were dipped into NaOH (30% at 85°C) polishing solution until a final thickness of 350 μm was reached; followed neutralization and RCA decontamination stages by putting them in a bath made of H2O2/NH4OH/DI H2O at 70°C, ...

  1. Optical coating uniformity of 200mm (8") diameter precut wafers (United States)

    Burt, Travis C.; Fisher, Mark; Brown, Dean; Troiani, David


    Automated spectroscopic profiling (mapping) of a 200 mm diameter near infrared high reflector (centered at 1064 nm) are presented. Spatial resolution at 5 mm or less was achieved using a 5 mm × 1.5 mm monochromatic beam. Reflection changes of 1.0% across the wafer diameter were observed under s-polarized and p- polarized conditions. Redundancy was established for each chord by re-measuring the center of the wafer and reproducibility of approximately used to measure the reflectance and transmittance of a sample across a range of angles (θi) at near normal angles of incidence (AOI). A recent development by Agilent Technologies, the Cary 7000 Universal Measurement Spectrophotometer (UMS) combines both reflection and transmission measurements from the same patch of a sample's surface in a single automated platform for angles of incidence in the range 5°use of MPS on the Cary 7000 UMS with rotational (Φ) and vertical (z) sample positioning control. MPS(θi,Φ,z) provides for automated unattended multi-angle R/T analysis of at 200 mm diameter samples with the goal to provide better spectroscopic measurement feedback into large wafer manufacturing to ensure yields are maximized, product quality is better controlled and waste is reduced before further down-stream processing.

  2. The influence of feature sidewall tolerance on minimum absorber thickness for LIGA x-ray masks

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Griffiths; J. M. Hruby; A. Ting


    Minimizing mask absorber thickness is an important practical concern in producing very small features by the LIGA process. To assist in this minimization, the authors have developed coupled numerical models describing both the exposure and development of a thick PMMA resist. The exposure model addresses multi-wavelength, one-dimensional x-ray transmission through multiple beam filters, through the mask substrate and absorber, and the subsequent attenuation and photon absorption in the PMMA resist. The development model describes one-dimensional dissolution of a feature and its sidewalls, taking into account the variation in absorbed dose through the PMMA thickness. These exposure and development models are coupled in a single interactive code, permitting the automated adjustment of mask absorber thickness to yield a prescribed sidewall taper or dissolution distance. They have used this tool to compute the minimum required absorber thickness yielding a prescribed sidewall tolerance for exposures performed at the ALS, SSRL and NSLS synchrotron sources. Results are presented as a function of the absorbed dose for a range of the prescribed sidewall tolerance, feature size, PMMA thickness, mask substrate thickness and the development temperature.

  3. Towards large size substrates for III-V co-integration made by direct wafer bonding on Si

    Directory of Open Access Journals (Sweden)

    N. Daix


    Full Text Available We report the first demonstration of 200 mm InGaAs-on-insulator (InGaAs-o-I fabricated by the direct wafer bonding technique with a donor wafer made of III-V heteroepitaxial structure grown on 200 mm silicon wafer. The measured threading dislocation density of the In0.53Ga0.47As (InGaAs active layer is equal to 3.5 × 109 cm−2, and it does not degrade after the bonding and the layer transfer steps. The surface roughness of the InGaAs layer can be improved by chemical-mechanical-polishing step, reaching values as low as 0.4 nm root-mean-square. The electron Hall mobility in 450 nm thick InGaAs-o-I layer reaches values of up to 6000 cm2/Vs, and working pseudo-MOS transistors are demonstrated with an extracted electron mobility in the range of 2000–3000 cm2/Vs. Finally, the fabrication of an InGaAs-o-I substrate with the active layer as thin as 90 nm is achieved with a Buried Oxide of 50 nm. These results open the way to very large scale production of III-V-o-I advanced substrates for future CMOS technology nodes.

  4. Identification and long term stability of DNA captured on a dental impression wafer. (United States)

    Kim, Maile; Siegler, Kate; Tamariz, Jeannie; Caragine, Theresa; Fernandez, Jill; Daronch, Marcia; Moursi, Amr


    The purpose of this study was to determine the quantity and quality of DNA extracted from a dental bite impression wafer immediately after impression and after 12 months of home storage. The authors' hypothesis was that the wafer would retain sufficient DNA with appropriate genetic markers to make an identification match. Two impression wafers (Toothprints(®) brand) were administered to 100 3- to 26-year-olds. A cotton swab was used as a control. DNA from wafers stored for 12 months at home were compared to DNA collected at time 0 and compared to swabs at specific sites to determine quality and accuracy. The amount of DNA captured and recovered was analyzed using MagAttract technology and a quantitative real-time polymerase chain reaction. Capillary gel electrophoresis was performed to determine the quality of the DNA profiles obtained from the wafers vs those generated from the swabs of each subject. Average DNA concentration was: 480 pg/μL (wafer at time 0); 392 pg/μL (wafer after 12 months kept by subjects); and 1,041 pg/μL (buccal swab). Sufficient DNA for human identification was recovered from all sets of wafers, producing clear DNA profiles and accurate matches to buccal swabs. No inhibitors were found that could interfere with DNA profiling. Toothprints® impression wafers can be useful for DNA collection and child identification. After 12 months, the wafer was still usable for DNA capture and identification match.

  5. Comparison and Efficacy of LigaSure and Rubber Band Ligature in Closing the Inflamed Cecal Stump in a Rat Model of Acute Appendicitis

    Directory of Open Access Journals (Sweden)

    Chun-Chieh Yeh


    Full Text Available Safety of either LigaSure or rubber band in closing inflamed appendiceal stump in acute appendicitis has been less investigated. In this study, cecal ligation followed by resecting inflamed cecum was performed to mimic appendectomy in a rat model of acute appendicitis. Rats were sacrificed immediately (Group A and 7 days (Group B after cecal resection, respectively. The cecal stumps were closed by silk ligature (S, 5 mm LigaSure (L, or rubber band (R. Seven days after cecal resection, the LigaSure (BL and silk subgroups (BS had significantly less intra-abdominal adhesion and better laparotomy wound healing than rubber band subgroup (BR. The initial bursting pressure at cecal stump was comparable among the three methods; along with tissue healing process, both BL and BS provided a higher bursting pressure than BR 7 days after appendectomy. BL subgroup had more abundant hydroxyproline deposition than BS and BR subgroup. Furthermore, serum TNF-α in BR group kept persistently increasing along with time after cecal resection. Thus, the finding that LigaSure but not rubber band is safe in sealing off the inflamed cecal stump in rat model of acute appendicitis suggests the possibility of applying LigaSure for appendectomy via single port procedure or natural orifice transluminal endoscopic surgery (NOTES.

  6. Analyses of crack growth along interface of patterned wafer-level Cu-Cu bonds

    DEFF Research Database (Denmark)

    Tvergaard, Viggo; Hutchinson, John W.


    . The computational model provides the resistance curve of macroscopic crack driving force versus crack advance as dependent on the work of separation and strength of the interface as well as the pattern geometry and the parameters controlling the plasticity of the Cu films. Plasticity in the Cu films makes a major...... on Si wafer substrates. Specimens were then produced by bringing the Cu surfaces into contact creating thermo-compression bonds. Interface toughness of these specimens was experimentally measured. The present study focuses on interface patterns comprised of bonded strips, called lines, alternating...... contribution to the macroscopic interface toughness measured by Tadepalli, Turner and Thompson. Highlighted in this study is the difficulty of accurately representing plastic yielding in the thin films and the challenge of capturing the full range of scales in a computational model....

  7. Attacks of the soccer teams participating in the champions league and the Serbian super liga

    Directory of Open Access Journals (Sweden)

    Janković Aleksandar


    Full Text Available The area of tactics in soccer game is of particular importance for modern soccer development. The analysis and improvement of spatio-temporal indicators as well as the game principles related to tactics may be crucial to the achievement of competitive results. This study is aimed at comparing tactical manifestations of the teams competing in the top quality European club competition, the Champions League, and the best Serbian soccer championship by analyzing competitive activity. The results of the conducted research were obtained by observing an overall of 20 randomly selected matches, 10 of the Champions League (CL and 10 of the Serbian Super Liga (SSL, which is a sufficient number of matches for making conclusions about the competitions respectively. In the previously designed observing protocol, using a method of notation, we analyzed all the attacks completed by shooting at the opponent's goal. The structure of successfully realized attacks was assessed on the basis of: accuracy, types of realized offensive actions; area of starting the action, manner of realization of passes completed (assists and distance from the goal from which a shot on goal was executed. The study showed that there are certain common characteristics, but also there are differences in the structure of successfully realized attacks between the two analyzed competitions. The teams of the CL competition had significantly greater number of effective attacks per match (p = 0. 006, they realized their offensive activities with slightly greater number of players (p = 0.002 and number of passes (p = 0.000, whereas there are no significant differences in the area of starting successful attacks, the manner of realization of assists and distance from which shots on goal were executed. The study results may define certain guidelines in training technology when preparing the teams of the SSL competition for taking part in the European soccer cups.

  8. Study of Si wafer surfaces irradiated by gas cluster ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Isogai, H. [Processing Technology, Silicon Business Group, Toshiba Ceramics Co., Ltd., 6-861-5 Higashikou Seiroumachi Kitakanbaragun, Niigata 957-0197 (Japan)]. E-mail:; Toyoda, E. [Processing Technology, Silicon Business Group, Toshiba Ceramics Co., Ltd., 6-861-5 Higashikou Seiroumachi Kitakanbaragun, Niigata 957-0197 (Japan); Senda, T. [Processing Technology, Silicon Business Group, Toshiba Ceramics Co., Ltd., 6-861-5 Higashikou Seiroumachi Kitakanbaragun, Niigata 957-0197 (Japan); Izunome, K. [Processing Technology, Silicon Business Group, Toshiba Ceramics Co., Ltd., 6-861-5 Higashikou Seiroumachi Kitakanbaragun, Niigata 957-0197 (Japan); Kashima, K. [New Business Creation, Toshiba Ceramics Co., Ltd., 30 Soya Hadano City, Kanagawa 257-0031 (Japan); Toyoda, N. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto Kamigouri, Hyogo 678-1205 (Japan); Yamada, I. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto Kamigouri, Hyogo 678-1205 (Japan)


    The surface structures of Si (1 0 0) wafers subjected to gas cluster ion beam (GCIB) irradiation have been analyzed by cross-sectional transmission electron microscopy (XTEM) and atomic force microscopy (AFM). GCIB irradiation is a promising technique for both precise surface etching and planarization of Si wafers. However, it is very important to understand the crystalline structure of Si wafers after GCIB irradiation. An Ar-GCIB used for the physically sputtering of Si atoms and a SF{sub 6}-GCIB used for the chemical etching of the Si surface are also analyzed. The GCIB irradiation increases the surface roughness of the wafers, and amorphous Si layers are formed on the wafer surface. However, when the Si wafers are annealed in hydrogen at a high temperature after the GCIB irradiation, the surface roughness decreases to the same level as that before the irradiation. Moreover, the amorphous Si layers disappear completely.

  9. Ultrahigh-vacuum field emitter array wafer tester

    Energy Technology Data Exchange (ETDEWEB)

    Gray, H.F.; Ardis, L.; Campisi, G.J.


    The device reported here allows the researcher the opportunity of gaining primitive yield information, threshold voltages, emission stability, and other information, e.g., gas effects, on field emitter arrays (FEA) which are microminiature ''vacuum tubes'' fabricated by microelectronic processing methods on silicon wafers, without scribing, dicing, and mounting each device on individual vacuum-compatible headers. This device also speeds up the entire data-acquisition process by requiring only one ultrahigh-vacuum pumpdown and one set of vacuum feedthroughs.

  10. Iterative bandgap engineering at selected areas of quantum semiconductor wafers. (United States)

    Stanowski, Radoslaw; Martin, Matthieu; Ares, Richard; Dubowski, Jan J


    We report on the application of a laser rapid thermal annealing technique for iterative bandgap engineering at selected areas of quantum semiconductor wafers. The approach takes advantage of the quantum well intermixing (QWI) effect for achieving targeted values of the bandgap in a series of small annealing steps. Each QWI step is monitored by collecting a photoluminescence map and, consequently, choosing the annealing strategy of the next step. An array of eight sites, 280 mum in diameter, each emitting at 1480 nm, has been fabricated with a spectral accuracy of better than 2 nm in a standard InGaAs/InGaAsP QW heterostructure that originally emitted at 1550 nm.

  11. Gabor filters and SVM classifier for pattern wafer segmentation (United States)

    Bourgeat, Pierrick T.; Meriaudeau, Fabrice; Gorria, Patrick; Tobin, Kenneth W.


    In the last decade, the accessibility of inexpensive and powerful computers has allowed true digital holography to be used for industrial inspection using microscopy. This technique allows capturing a complex image of a scene (i.e. containing magnitude and phase), and reconstructing the phase and magnitude information. Digital holograms give a new dimension to texture analysis since the topology information can be used as an additional way to extract features. This new technique can be used to extend previous work on image segmentation of patterned wafers for defect detection. This paper presents a comparison between the features obtained using Gabor filtering on complex images under illumination and focus variations.

  12. Wafer hot spot identification through advanced photomask characterization techniques: part 2 (United States)

    Choi, Yohan; Green, Michael; Cho, Young; Ham, Young; Lin, Howard; Lan, Andy; Yang, Richer; Lung, Mike


    Historically, 1D metrics such as Mean to Target (MTT) and CD Uniformity (CDU) have been adequate for mask end users to evaluate and predict the mask impact on the wafer process. However, the wafer lithographer's process margin is shrinking at advanced nodes to a point that classical mask CD metrics are no longer adequate to gauge the mask contribution to wafer process error. For example, wafer CDU error at advanced nodes is impacted by mask factors such as 3-dimensional (3D) effects and mask pattern fidelity on sub-resolution assist features (SRAFs) used in Optical Proximity Correction (OPC) models of ever-increasing complexity. To overcome the limitation of 1D metrics, there are numerous on-going industry efforts to better define wafer-predictive metrics through both standard mask metrology and aerial CD methods. Even with these improvements, the industry continues to struggle to define useful correlative metrics that link the mask to final device performance. In part 1 of this work, we utilized advanced mask pattern characterization techniques to extract potential hot spots on the mask and link them, theoretically, to issues with final wafer performance. In this paper, part 2, we complete the work by verifying these techniques at wafer level. The test vehicle (TV) that was used for hot spot detection on the mask in part 1 will be used to expose wafers. The results will be used to verify the mask-level predictions. Finally, wafer performance with predicted and verified mask/wafer condition will be shown as the result of advanced mask characterization. The goal is to maximize mask end user yield through mask-wafer technology harmonization. This harmonization will provide the necessary feedback to determine optimum design, mask specifications, and mask-making conditions for optimal wafer process margin.

  13. Influência do tempo e deformação na microestrutura de ligas de alumínio reciclado condicionadas para tixoconformação


    Alves, Gianni Ferreira; Vieira, Estéfano Aparecido; Oliveira, José Roberto de


    Um dos pré-requisitos para o processo de tixoconformação de ligas, é que estas apresentem microestruturas globulares. Esse trabalho utilizou o método da deformação seguido por recristalização com o objetivo de determinar a deformação e o tempo mínimos necessários para completa globularização de duas novas ligas de Al no estado semi-sólido (ESS). Buscou-se, também, encontrar a deformação necessária para um máximo refinamento microestrutural. As ligas foram fundidas a partir de sucatas de latas...

  14. Intervenção numa equipa profissional de futebol da Segunda Liga Portuguesa - Época 2012/2013


    Moreira, Miguel


    Relatório de Estágio apresentado para obtenção do grau de Mestre em Desporto com Especialização em Treino Desportivo Resumo Este relatório aborda a intervenção na União Desportiva Oliveirense, equipa profissional de futebol da segunda liga portuguesa – época 2012/2013. Tem como objetivos essenciais aprofundar os conhecimentos do mestrando numa realidade profissional e promover a sua atuação / intervenção no contexto prático. Privilegia-se, como contexto de caracterização, o ...

  15. Wafer-level testing and test during burn-in for integrated circuits

    CERN Document Server

    Bahukudumbi, Sudarshan


    Wafer-level testing refers to a critical process of subjecting integrated circuits and semiconductor devices to electrical testing while they are still in wafer form. Burn-in is a temperature/bias reliability stress test used in detecting and screening out potential early life device failures. This hands-on resource provides a comprehensive analysis of these methods, showing how wafer-level testing during burn-in (WLTBI) helps lower product cost in semiconductor manufacturing.Engineers learn how to implement the testing of integrated circuits at the wafer-level under various resource constrain

  16. Estudo da adaptação marginal de amalgamas de prata sob a influencia de ligas, triturações e brunidura


    Jose Roberto Lovadino


    Resumo: O objetivo desse trabalho foi verificar o nivel de adaptação da superfície da parede lateralde corpos de prova onfeccionados em amâlgamas de prata. Foram realizados corpos de prova através de três ligas de prata _diferentes, cujosnomes comerciais foram Novo True Dentalloy, Novaloy e Sybraloy. - Essas ligas foram trituradas mecanicamente e manualmente, conforme Especificação n9 1 da Associação Dentaria Americana e condéns adas com condensadór tipo Hollemback n 9 1, sob pressão de 1 kgf...

  17. Desenvolvimento de dispositivo, adaptado à tocha SATG, para a realização de revestimento duro, utilizando ligas, em forma de pó


    Paulo Cesar Moselli


    Este trabalho inova a aplicação de revestimentos duros usando o processo de soldagem SATG (Soldagem ao Arco Tungstênio com Atmosfera Gasosa) utilizando ligas, em forma de pó, incorporadas diretamente à poça de solda. Devido à boa resistência ao desgaste, utilizou-se a liga Stellite 6, no substrato SAE 1020. Dados de microdureza Vickers, taxa de deposição, diluição, análise micrográfica e desgaste foram comparados com resultados do PAT-P (Plasma por Arco Transferido-Pó) e permitiram avaliar a...

  18. Corrosão e propriedades mecânicas de tração e fadiga da liga de alumínio 7050-T73651


    Edison Almeida Rodrigues


    Resumo: Existe uma tendência promissora para uso de ligas à base de alumínio na indústria automotiva considerando vantagens relacionadas às características deste tipo de material. Entretanto, é necessário estudos para obter dados que permitam verificar a suscetibilidade desse material ao processo de corrosão, ao interagir com os diversos tipos de combustíveis que hoje são utilizados. Este trabalho visou estudar a corrosão da liga de alumínio 7050-T73651 em etanol combustível, enfatizando poss...

  19. Wafer Defect Detection Using Directional Morphological Gradient Techniques

    Directory of Open Access Journals (Sweden)

    Gongyuan Qu


    Full Text Available Accurate detection and classification of wafer defects constitute an important component of the IC production process because together they can immediately improve the yield and also provide information needed for future process improvements. One class of inspection procedures involves analyzing surface images. Because of the characteristics of the design patterns and the irregular size and shape of the defects, linear processing methods, such as Fourier transform domain filtering or Sobel edge detection, are not as well suited as morphological methods for detecting these defects. In this paper, a newly developed morphological gradient technique using directional components is applied to the detection and isolation of wafer defects. The new methods are computationally efficient and do not rely on a priori knowledge of the specific design pattern to detect particles, scratches, stains, or missing pattern areas. The directional components of the morphological gradient technique allow direction specific edge suppression and reduce the noise sensitivity. Theoretical analysis and several examples are used to demonstrate the performance of the directional morphological gradient methods.

  20. Steel bridge fatigue crack detection with piezoelectric wafer active sensors (United States)

    Yu, Lingyu; Giurgiutiu, Victor; Ziehl, Paul; Ozevin, Didem; Pollock, Patrick


    Piezoelectric wafer active sensors (PWAS) are well known for its dual capabilities in structural health monitoring, acting as either actuators or sensors. Due to the variety of deterioration sources and locations of bridge defects, there is currently no single method that can detect and address the potential sources globally. In our research, our use of the PWAS based sensing has the novelty of implementing both passive (as acoustic emission) and active (as ultrasonic transducers) sensing with a single PWAS network. The combined schematic is using acoustic emission to detect the presence of fatigue cracks in steel bridges in their early stage since methods such as ultrasonics are unable to quantify the initial condition of crack growth since most of the fatigue life for these details is consumed while the fatigue crack is too small to be detected. Hence, combing acoustic emission with ultrasonic active sensing will strengthen the damage detection process. The integration of passive acoustic emission detection with active sensing will be a technological leap forward from the current practice of periodic and subjective visual inspection, and bridge management based primarily on history of past performance. In this study, extensive laboratory investigation is performed supported by theoretical modeling analysis. A demonstration system will be presented to show how piezoelectric wafer active sensor is used for acoustic emission. Specimens representing complex structures are tested. The results will also be compared with traditional acoustic emission transducers to identify the application barriers.

  1. Correlated Three-Dimensional Imaging of Dislocations: Insights into the Onset of Thermal Slip in Semiconductor Wafers (United States)

    Hänschke, D.; Danilewsky, A.; Helfen, L.; Hamann, E.; Baumbach, T.


    Correlated x-ray diffraction imaging and light microscopy provide a conclusive picture of three-dimensional dislocation arrangements on the micrometer scale. The characterization includes bulk crystallographic properties like Burgers vectors and determines links to structural features at the surface. Based on this approach, we study here the thermally induced slip-band formation at prior mechanical damage in Si wafers. Mobilization and multiplication of preexisting dislocations are identified as dominating mechanisms, and undisturbed long-range emission from regenerative sources is discovered.

  2. Penggunaan Limbah Kopi Sebagai Bahan Penyusun Ransum Itik Peking dalam Bentuk Wafer Ransum Komplit

    Directory of Open Access Journals (Sweden)

    Muhammad Daud


    Full Text Available Effect of coffee waste as component of compiler ration peking duck in the form of wafer complete ration ABSTRACT. Coffee waste is a by-product of coffee processing that potential to be used as feed stuff for peking duck. The weakness of this coffee waste, among others, is perishable, voluminous (bulky and the availability was fluctuated so the processing technology is needed to make this vegetable waste to be durable, easy to stored and to be given to livestock. To solve this problem vegetable waste could be formed as wafer. This research was conducted to study effectiveness of coffee waste as component of compiler ration peking duck in the form of wafer complete ration This experiment was run in completely randomized design which consist of 4 feed treatment and 3 replications.  Ration used was consisted of  P0 = wafer complete ration 0% coffee waste (control, P1 = wafer complete ration 2,5% coffee waste, P2 = wafer complete ration 5% coffee waste, and P3 = Wafer complete ration 7,5% coffee waste. The Variables observed were: physical characteristic (aroma, color, and wafer density and palatability of wafer complete ration. Data collected was analyzed with ANOVA and Duncan Range Test would be used if the result was significantly different. The result showed that the density of wafer complete ration coffee waste was significantly (P< 0.05 differences between of treatment. Mean density wafer complete ration equal to: P0= 0,52±0,03, P1 =0,67±0,04, P2 =0,72±0,03, and P3 = 0,76±0.05 g/cm3. Wafer complete ration coffee waste palatability was significantly (P< 0.05 differences between of treatment. It is concluded that of wafer complete ration composition 5 and 7,5% coffee waste was significantly wafer palatability and gave a highest wafer density. The ration P0 was the most palatable compare to other treatments for the experimental peking duck.

  3. Image feature analysis of plasma spot produced from femtosecond laser ablation for silicon wafer (United States)

    Wang, Fu-bin; Zhao, Li-hong; Tu, Paul; Liu, Yang; Chen, Jian-xiong


    When using a femtosecond laser to machine a single-crystal silicon wafer, it is accompanied with a diffraction spot of plasma. The existing literature reports that the brightness of the image of plasma can be used as an indicator to online measure the depth of the machined groove on a micrometer scale. Because the plasma spot is influenced by eruption and partial occlusion of ablated material, this method, which simply relies on the spot image brightness as a feedback parameter, is not reliable or accurate. The pixel area, perimeter, and brightness characteristics of the plasma spot image need to be comprehensively analyzed to provide a reliable and accurate feedback to establish close-loop micromachining technology. Therefore, we first analyze the chirped amplification principle of generating a femtosecond laser and the application of the diffraction spot of plasma during the micromachining processing using the femtosecond laser. Second, we experiment using femtosecond laser ablation with a piece of 10×10 mm and thickness of 650±10 μm single-crystal silicon wafer to obtain the corresponding relational data among parameters of laser processing power, processing speed, and laser spot image of plasma. Third, aiming at the characteristic of dim target of the laser spot image, the two-dimensional Otsu (maximum class square error method) is used to segment the laser spot image to improve the segmentation accuracy of the laser spot image. Finally, we analyze the relationship among area, perimeter of the laser spot image, and laser energy; the relationship among area, perimeter of the laser spot image, and the machined depth of groove; the relationship between brightness of the laser spot image and laser output power; and the relationship between brightness of laser spot image and machining speed.

  4. Preparation and characterization of ultra-thin amphiphobic coatings on silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Mou, Chun-Yueh, E-mail:; Yuan, Wei-Li; Shih, Chih-Hsin


    Fluorine-based amphiphobic coatings have been widely used in commercial domestic utensils and textiles to repel water and oil contaminants. However, few reports from the literature survey have discussed the effects on amphiphobicity of the nano- to micro-scale surface features of such a coating. In this research thin amphiphobic epoxy coatings based on a mixture of bisphenol A diglycidyl ether, tetraethylorthosilicate (TEOS), and a particular alkoxy silane with fluorinated side chains (F-silane) are deposited on silicon wafers. Film amphiphobicity is characterized by the measurement of water and oil contact angles of the coating. Film morphology is revealed in the scanned images using atomic force microscopy. The deposited films free of F-silane are about 10 nm thick. When a small amount of F-silane was firstly added, the water and oil contact angles of the deposited films jumped up to 107° and 69° respectively and then flattened out with increased F-silane. Water droplets gave an average plateau contact angle about 110°, while vegetable oil ones, 40°. It was noted that there is a dramatic decrease in the lyophobicity causing a reduction in contact angles. However, surface lyophobicity also depends on sub-microscopic surface structures. In addition, by increasing TEOS, it was shown that the formed silica sols or granules were helpful in enhancing the mechanical strength along with retaining the lyophobicity of the film. - Highlights: • Epoxy ultrathin films about 10 nm thick deposited on silicon wafer. • Nominal fluorinated silane added to epoxy coatings for amphiphobicity. • Surface lyophobicity retained by sub-micrometer granules in ultrathin coatings. • Film hardness improved by adding tetraethylorthosilicate.

  5. Heat transport in cold-wall single-wafer low pressure chemical-vapor-deposition reactors

    NARCIS (Netherlands)

    Hasper, A.; Schmitz, J.E.J.; Holleman, J.; Verweij, J.F.


    A model is formulated to understand and predict wafer temperatures in a tungsten low pressure chemical‐vapor‐deposition (LPCVD) single‐wafer cold‐wall reactor equipped with hot plate heating. The temperature control is usually carried out on the hot plate temperature. Large differences can occur

  6. Bond strength tests between silicon wafers and duran tubes (fusion bonded fluidic interconnects)

    NARCIS (Netherlands)

    Fazal, I.; Berenschot, Johan W.; de Boer, J.H.; Jansen, Henricus V.; Elwenspoek, Michael Curt


    The fusion bond strength of glass tubes with standard silicon wafers is presented. Experiments with plain silicon wafers and those coated with silicon oxide and silicon nitride are presented. Results obtained are discussed in terms of homogeneity and strength of fusion bond. High pressure testing

  7. Systematic characterization of key parameters of hermetic wafer-level Cu-Sn SLID bonding

    NARCIS (Netherlands)

    Wiel, H.J. van de; Vardøy, A.S.B.; Hayes, G.; Kouters, M.H.M.; Waal, A. van der; Erinc, M.; Lapadatu, A.; Martinsen, S.; Taklo, M.M.V.; Fischer, H.R.


    Hermetic wafer-level encapsulation of atmosphere sensitive Micro-Electric-Mechanical Systems (MEMS) devices is vital to achieve a high yield, a high performance and a long operating lifetime. An interesting and gradually more employed packaging technique is flux-less wafer-level copper-tin (Cu-Sn)

  8. Wafer-level packaged RF-MEMS switches fabricated in a CMOS fab

    NARCIS (Netherlands)

    Tilmans, H.A.C.; Ziad, H.; Jansen, Henricus V.; Di Monaco, O.; Jourdain, A.; De Raedt, W.; Rottenberg, X.; De Backer, E.; Decoussernaeker, A.; Baert, K.


    Reports on wafer-level packaged RF-MEMS switches fabricated in a commercial CMOS fab. Switch fabrication is based on a metal surface micromachining process. A novel wafer-level packaging scheme is developed, whereby the switches are housed in on-chip sealed cavities using benzocyclobutene (BCB) as

  9. Charge carrier Density Imaging / IR lifetime mapping of Si wafers by Lock-In Thermography

    NARCIS (Netherlands)

    Van der Tempel, L.


    ABSTRACT Minority carrier lifetime imaging by lock-in thermography of passivated silicon wafers for photovoltaic cells has been developed for the public Pieken in de Delta project geZONd. CONCLUSIONS Minority carrier lifetime imaging by lock-in thermography of passivatedsilicon wafers is released

  10. Development of low-temperature wafer level vacuum packaging for microsensors (United States)

    Huang, Wei-Feng; Shie, Jin-Shown; Lee, Cheng-Kuo; Gong, Shih C.; Peng, Cheng-Jien


    Wafer level packaging received lots of attention in microsystems recently. Because it shows the potential to reduce the packaging can be increased. However, there is a limitation of commercialized wafer bonding technology, i.e., the high process temperature, such as 1000 degrees C of silicon fusion bonding, and 450 degrees C of anodic bonding.A novel low temperature wafer bonding with process temperature lower than 160 degrees C is proposed, it applies the In-Sn alloy to form the interface of wafer bonding. The experiment results show helium leak test of 6 X 10-9 torr-liter/sec, and a tensile strength as high as 200kg/cm2. Reliability test after 1500 temperature cycles between -10 to 80 degrees C also shows no trace of degradation compared to the initial quality of the samples. This low temperature soldering process demonstrates its promising potential at the wafer level packaging in industrial production.

  11. Wafer size effect on material removal rate in copper CMP process

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, Minjong; Jang, Soocheon; Park, Inho; Jeong, Haedo [Pusan National University, Busan (Korea, Republic of)


    The semiconductor industry has employed the Chemical mechanical planarization (CMP) to enable surface topography control. Copper has been used to build interconnects because of its low-resistivity and high-electromigration. In this study, the effect of wafer size on the Material removal rate (MRR) in copper CMP process was investigated. CMP experiments were conducted using copper blanket wafers with diameter of 100, 150, 200 and 300 mm, while temperature and friction force were measured by infrared and piezoelectric sen-sors. The MRR increases with an increase in wafer size under the same process conditions. The wafer size increased the sliding distance of pad, resulting in an increase in the process temperature. This increased the process temperature, accelerating the chemical etching rate and the dynamic etch rate. The sliding distance of the pad was proportional to the square of the wafer radius; it may be used to predict CMP results and design a CMP machine.

  12. Simulation Research on Micro Contact Based on Force in Silicon Wafer Rotation Grinding (United States)

    Ren, Qinglei; Wei, Xin; Xie, Xiaozhu; Hu, Wei


    Silicon wafer rotation grinding with cup type diamond wheel is a typical ultra precision grinding process. In this paper, a simulation model based on force for micro contact between wheel micro unit and silicon wafer is established from the stable ductile grinding process. Micro contact process in grinding is simulated using the nonlinear explicit finite element analysis software LS-DYNA. The stress-strain results on silicon wafer and wheel micro unit are analyzed by finite element method. The results show that the critical displacement and load corresponding elastic to plastic - plastic to brittle exist on silicon wafer. In silicon plastic zone tangential sliding can produce plastic groove and uplift. Wear of wheel micro unit can be based on the simulation data to judge. The research provides support for wafer grinding and wheel wear mechanism.

  13. Stickers versus wafers: The value of resource in a public goods game with children

    Directory of Open Access Journals (Sweden)

    Phiética Raíssa Rodrigues da Silva

    Full Text Available Abstract We investigated how the type of resource, food (wafer or non-food (sticker, age and sex influence cooperation in children. 251 children were tested in a public goods game during eight rounds in two experimental conditions: wafer or sticker condition. Wafers were all of the same kind but stickers were varied. The results indicated that 1 older children donated more stickers than younger children, but they did not differ in relation to wafer donations; and 2 sticker donations remained high along the rounds, while wafer donations decreased. We propose that different strategies may be adopted according to the quality, particularly to the diversity of the resource used, and the cost of cooperation may be overcome when it is more advantageous to wait for a future reward.

  14. Homogenization of CZ Si wafers by Tabula Rasa annealing

    Energy Technology Data Exchange (ETDEWEB)

    Meduna, M., E-mail: mjme@physics.muni.c [Department of Condensed Matter Physics, Masaryk University, Kotlarska 2, CZ-61137 Brno (Czech Republic); Caha, O.; Kubena, J.; Kubena, A. [Department of Condensed Matter Physics, Masaryk University, Kotlarska 2, CZ-61137 Brno (Czech Republic); Bursik, J. [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, CZ-61662 Brno (Czech Republic)


    The precipitation of interstitial oxygen in Czochralski grown silicon has been investigated by infrared absorption spectroscopy, chemical etching, transmission electron microscopy and X-ray diffraction after application of homogenization annealing process called Tabula Rasa. The influence of this homogenization step consisting in short time annealing at high temperature has been observed for various temperatures and times. The experimental results involving the interstitial oxygen decay in Si wafers and absorption spectra of SiO{sub x} precipitates during precipitation annealing at 1000 deg. C were compared with other techniques for various Tabula Rasa temperatures. The differences in oxygen precipitation, precipitate morphology and evolution of point defects in samples with and without Tabula Rasa applied is evident from all used experimental techniques. The results qualitatively correlate with prediction of homogenization annealing process based on classical nucleation theory.

  15. Chemical strategies for die/wafer submicron alignment and bonding.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, James Ellis; Baca, Alicia I.; Chu, Dahwey; Rohwer, Lauren Elizabeth Shea


    This late-start LDRD explores chemical strategies that will enable sub-micron alignment accuracy of dies and wafers by exploiting the interfacial energies of chemical ligands. We have micropatterned commensurate features, such as 2-d arrays of micron-sized gold lines on the die to be bonded. Each gold line is functionalized with alkanethiol ligands before the die are brought into contact. The ligand interfacial energy is minimized when the lines on the die are brought into registration, due to favorable interactions between the complementary ligand tails. After registration is achieved, standard bonding techniques are used to create precision permanent bonds. We have computed the alignment forces and torque between two surfaces patterned with arrays of lines or square pads to illustrate how best to maximize the tendency to align. We also discuss complex, aperiodic patterns such as rectilinear pad assemblies, concentric circles, and spirals that point the way towards extremely precise alignment.

  16. Delineation of Crystalline Extended Defects on Multicrystalline Silicon Wafers

    Directory of Open Access Journals (Sweden)

    Mohamed Fathi


    Full Text Available We have selected Secco and Yang etch solutions for the crystalline defect delineation on multicrystalline silicon (mc-Si wafers. Following experimentations and optimization of Yang and Secco etching process parameters, we have successfully revealed crystalline extended defects on mc-Si surfaces. A specific delineation process with successive application of Yang and Secco agent on the same sample has proved the increased sensitivity of Secco etch to crystalline extended defects in mc-Si materials. The exploration of delineated mc-Si surfaces indicated that strong dislocation densities are localized mainly close to the grain boundaries and on the level of small grains in size (below 1 mm. Locally, we have observed the formation of several parallel dislocation lines, perpendicular to the grain boundaries. The overlapping of several dislocations lines has revealed particular forms for etched pits of dislocations.

  17. Comparison of texture features for segmentation of patterned wafers (United States)

    Bourgeat, Pierrick; Meriaudeau, Fabrice; Tobin, Kenneth W., Jr.; Gorria, Patrick


    In the last decade, the accessibility of inexpensive and powerful computers has allowed true digital holography to be used for industrial inspection using a microscopy. This technique allows capturing a complex image of a scene, and reconstructing the phase and magnitude information. This type of image gives a new dimension to texture analysis since the topology information can be used as an additional way to extract features. This new technique can be used to extend our previous work on image segmentation of patterned wafers for defect detection. This paper presents a comparison between the features obtained using Gabor filtering on complex (i.e. containing magnitude and phase) images under illumination and focus variations.

  18. Fabrication of PIN diode detectors on thinned silicon wafers

    CERN Document Server

    Ronchin, Sabina; Dalla Betta, Gian Franco; Gregori, Paolo; Guarnieri, Vittorio; Piemonte, Claudio; Zorzi, Nicola


    Thin substrates are one of the possible choices to provide radiation hard detectors for future high-energy physics experiments. Among the advantages of thin detectors are the low full depletion voltage, even after high particle fluences, the improvement of the tracking precision and momentum resolution and the reduced material budget. In the framework of the CERN RD50 Collaboration, we have developed p-n diode detectors on membranes obtained by locally thinning the silicon substrate by means of tetra-methyl ammonium hydroxide etching from the wafer backside. Diodes of different shapes and sizes have been fabricated on 57 and 99mum thick membranes. They have been tested, showing a very low leakage current ( less than 0.4nA/cm**2) and, as expected, a very low depletion voltage ( less than 1V for the 57mum membrane). The paper describes the technological approach used for devices fabrication and reports selected results from the electrical characterization.

  19. Ambient plasma treatment of silicon wafers for surface passivation recovery (United States)

    Ge, Jia; Prinz, Markus; Markert, Thomas; Aberle, Armin G.; Mueller, Thomas


    In this work, the effect of an ambient plasma treatment powered by compressed dry air on the passivation quality of silicon wafers coated with intrinsic amorphous silicon sub-oxide is investigated. While long-time storage deteriorates the effective lifetime of all samples, a short ambient plasma treatment improves their passivation qualities. By studying the influence of the plasma treatment parameters on the passivation layers, an optimized process condition was identified which even boosted the passivation quality beyond its original value obtained immediately after deposition. On the other hand, the absence of stringent requirement on gas precursors, vacuum condition and longtime processing makes the ambient plasma treatment an excellent candidate to replace conventional thermal annealing in industrial heterojunction solar cell production.

  20. Ligas Agrarias en Chaco y Corrientes. Experiencias de organización campesina en contextos de transformación territorial

    Directory of Open Access Journals (Sweden)

    Analía Percíncula


    Full Text Available La última dictadura militar arrasó con los procesos organizativos de todo el país, a la vez que introdujo las bases del modelo de acumulación neoliberal. En el nordeste argentino esto implicó, entre otras cosas, la represión y desarticulación de las Ligas Agrarias Chaqueñas y de las Ligas Agrarias Correntinas, organizaciones que en ambos casos representaron las reivindicaciones de los sectores rurales subalternos. Paralelamente, se produjo el desmantelamiento de las producciones de algodón en el Chaco y de tabaco criollo en Corrientes, las cuales estaban en manos de productores directos, quienes se habían organizado en sus respectivas Ligas Agrarias.En este trabajo proponemos un acercamiento, en clave comparativa, a las transformaciones de la estructura agropecuaria que caracterizó a ambas provincias hasta la década del 70 y los actores colectivos conformados a partir de dicha red de relaciones socioeconómicas y políticas, es decir, las Ligas Agrarias Chaqueñas y Correntinas.

  1. Acquisition of negative complement regulators by the saprophyte Leptospira biflexa expressing LigA or LigB confers enhanced survival in human serum. (United States)

    Castiblanco-Valencia, Mónica M; Fraga, Tatiana R; Breda, Leandro C D; Vasconcellos, Sílvio A; Figueira, Cláudio P; Picardeau, Mathieu; Wunder, Elsio; Ko, Albert I; Barbosa, Angela S; Isaac, Lourdes


    Leptospiral immunoglobulin-like (Lig) proteins are surface exposed molecules present in pathogenic but not in saprophytic Leptospira species. We have previously shown that Lig proteins interact with the soluble complement regulators Factor H (FH), FH like-1 (FHL-1), FH related-1 (FHR-1) and C4b Binding Protein (C4BP). In this study, we used the saprophyte L. biflexa serovar Patoc as a surrogate host to address the specific role of LigA and LigB proteins in leptospiral complement evasion. L. biflexa expressing LigA or LigB was able to acquire FH and C4BP. Bound complement regulators retained their cofactor activities of FI in the proteolytic cleavage of C3b and C4b. Moreover, heterologous expression of ligA and ligB genes in the saprophyte L. biflexa enhanced bacterial survival in human serum. Complement deposition on lig-transformed L. biflexa was assessed by flow cytometry analysis. With regard to MAC deposition, L. biflexa expressing LigA or LigB presented an intermediate profile: MAC deposition levels were greater than those found in the pathogenic L. interrogans, but lower than those observed for L. biflexa wildtype. In conclusion, Lig proteins contribute to in vitro control of complement activation on the leptospiral surface, promoting an increased bacterial survival in human serum. Copyright © 2016 European Federation of Immunological Societies. All rights reserved.

  2. Transparent masks for aligned deep x-ray lithography/LIGA: low-cost high-performance alternative using glass membranes (United States)

    Kupka, Roland K.; Megtert, Stephan; Roulliay, Marc; Bouamrane, Faycal


    Deep x-ray lithography/LIGA has proven to be a well established framework of x-ray based technologies for the fabrication of microstructures and pseudo three-dimensional objects. Inherently, x-ray lithography/LIGA is not fully three-dimensional because of the principle of simple shadow printing onto resists of constant thickness. Thus, it would be impossible to obtain 3D spheres, but series of stacked monolithic 2D cylinders. Hence, until recently, LIGA was mainly concerned with simple uni-level (1D) monolithic structures, using optically opaque mask-membranes like Be, Si or Ti with grown-on Au absorbers. In the course for mastering pseudo three-dimensional microstructures like micro-coils or electromagnetic applications, an alignment in between the lithographic steps becomes necessary which requires optically transparent membrane materials, if optical alignment is chosen. Diamond or SiC membranes are the actual suitable materials for such purposes, but their pricing and/or process robustness inhibit their frequent use in simple projects. We would like to report on a new promising material: a glued-on thin glass membrane. The advantages are incomparably lower costs compared to Diamond or SiC technologies, a considerable ease of fabrication, handling, quite favorable mechanical/optical properties, sufficient for lithographic purposes and multi-level deep x-ray lithography/LIGA activities.

  3. An evaluation of DNA yield, DNA quality and bite registration from a dental impression wafer. (United States)

    Ellis, Mark A; Song, Fengyu; Parks, Edwin T; Eckert, George J; Dean, Jeffrey A; Windsor, L Jack


    The authors determined the amount and quality of the DNA captured by a bite impression wafer and analyzed any inaccuracies in the impression wafer. The authors made bite registrations for subjects aged 7 to 12 years by using a dental impression wafer (Toothprints, Kerr, Orange, Calif.), obtained an oral rinse sample, took cheek cells by using buccal swabs and made an alginate impression to pour a stone model. They extracted and quantified the DNA from the dental impression wafer, mouthwash and buccal swabs by using the Quant-iT PicoGreen (Invitrogen, Carlsbad, Calif.) assay and a real-time polymerase chain reaction (RT-PCR) assay. They compared the stone models and imprints from the wafer. The average amounts of DNA determined by using Quant-iT PicoGreen from the buccal swab, mouthwash and dental impression wafer samples were 113.61, 509.57 and 1.03 micrograms, respectively. The average amounts of DNA determined by using RT-PCR from the buccal swab, mouthwash and dental impression wafer samples were 11.5240, 22.2540 and 0.0279 mug, respectively. The bite registrations and stone models had an average of 14 percent of mismatches. The dental impression wafers captured DNA but not in high quantities. They did not produce an accurate representation of the dentition. The dental impression wafers captured enough DNA to permit amplification. The accuracy of the bite registration was not sufficient for identification purposes. Therefore, dental impression wafers may be useful only as a reservoir for DNA.

  4. Infrared differential interference contrast microscopy for overlay metrology on 3D-interconnect bonded wafers (United States)

    Ku, Yi-sha; Shyu, Deh-Ming; Lin, Yeou-Sung; Cho, Chia-Hung


    Overlay metrology for stacked layers will be playing a key role in bringing 3D IC devices into manufacturing. However, such bonded wafer pairs present a metrology challenge for optical microscopy tools by the opaque nature of silicon. Using infrared microscopy, silicon wafers become transparent to the near-infrared (NIR) wavelengths of the electromagnetic spectrum, enabling metrology at the interface of bonded wafer pairs. Wafers can be bonded face to face (F2F) or face to back (F2B) which the stacking direction is dictated by how the stacks are carried in the process and functionality required. For example, Memory stacks tend to use F2B stacking enables a better managed design. Current commercial tools use single image technique for F2F bonding overlay measurement because depth of focus is sufficient to include both surfaces; and use multiple image techniques for F2B overlay measurement application for the depth of focus is no longer sufficient to include both stacked wafer surfaces. There is a need to specify the Z coordinate or stacking wafer number through the silicon when visiting measurement wafer sites. Two shown images are of the same (X, Y) but separate Z location acquired at focus position of each wafer surface containing overlay marks. Usually the top surface image is bright and clear; however, the bottom surface image is somewhat darker and noisier as an adhesive layer is used in between to bond the silicon wafers. Thus the top and bottom surface images are further processed to achieve similar brightness and noise level before merged for overlay measurement. This paper presents a special overlay measurement technique, using the infrared differential interference contrast (DIC) microscopy technique to measure the F2B wafer bonding overlay by a single shot image. A pair of thinned wafers at 50 and 150 μm thickness is bonded on top of a carrier wafer to evaluate the bonding overlay. It works on the principle of interferometry to gain information about the


    Directory of Open Access Journals (Sweden)

    Erna Rusliana Muhamad Saleh


    Full Text Available Wafer is type of biscuit frequently found on expired condition in market, therefore prediction method should be implemented to avoid this condition. apart from the prediction of shelf-life of wafer done by laboratory test, which were time-consuming, expensive, required trained panelists, complex equipment and suitable ambience, artificial neural network (ANN based dielectric parameters was proposed in nthis study. The aim of study was to develop model to predict shelf-life employing aNN based capacitance parameter. Back propagation algorithm with trial and error was applied in variations of nodes per hidden layer, number of hidden layers, activation functions, the function of learnings and epochs. The result of study was the model was able to predict wafer shelf-life. The accuracy level was shown by low MSE value (0.01 and high coefficient correlation value (89.25%. Keywords: artificial Neural Network, shelf-life, waffer, dielectric, capacitance   ABSTRAK Wafer adalah jenis makanan kering yang sering ditemukan kedaluwarsa. Penentuan masa kedaluwarsa dengan observasi laboratorium memiliki beberapa kelemahan, diantaranya memakan waktu, panelis terlatih, suasana yang tepat, biaya dan alat uji yang kompleks. alternatif solusinya adalah penggunaan artificial Neural Network (ANN berbasiskan parameter kapasitansi. Tujuan kerja ilmiah ini adalah untuk memprediksi masa kedaluwarsa wafer menggunakan aNN berbasiskan parameter kapasitansi. algoritma pembelajaran yang digunakan adalah Backpropagation dengan trial and error variasi jumlah node per hidden layer, jumlah hidden layer, fungsi aktivasi, fungsi pembelajaran dan epoch. Hasil prediksi menunjukkan bahwa aNN hasil pelatihan yang dikombinasikan dengan parameter kapasitansi mampu memprediksi masa kedaluwarsa wafer dengan MSE terendah 0,01 dan R tertinggi 89,25%. Kata kunci: Jaringan Syaraf Tiruan, masa kedaluwarsa, wafer, dielektrik, kapasitansi

  6. Validation of thermodesorption method for analysis of semi-volatile organic compounds adsorbed on wafer surface. (United States)

    Hayeck, Nathalie; Gligorovski, Sasho; Poulet, Irène; Wortham, Henri


    To prevent the degradation of the device characteristics it is important to detect the organic contaminants adsorbed on the wafers. In this respect, a reliable qualitative and quantitative analytical method for analysis of semi-volatile organic compounds which can adsorb on wafer surfaces is of paramount importance. Here, we present a new analytical method based on Wafer Outgassing System (WOS) coupled to Automated Thermal Desorber-Gas chromatography-Mass spectrometry (ATD-GC-MS) to identify and quantify volatile and semi-volatile organic compounds from 6", 8" and 12" wafers. WOS technique allows the desorption of organic compounds from one side of the wafers. This method was tested on three important airborne contaminants in cleanroom i.e. tris-(2-chloroethyl) phosphate (TCEP), tris-(2-chloroisopropyl) phosphate (TCPP) and diethyl phthalate (DEP). In addition, we validated this method for the analysis and quantification of DEP, TCEP and TCPP and we estimated the backside organic contamination which may contribute to the front side of the contaminated wafers. We are demonstrating that WOS/ATD-GC-MS is a suitable and highly efficient technique for desorption and quantitative analysis of organophosphorous compounds and phthalate ester which could be found on the wafer surface. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Intrinsic Gettering in Nitrogen-Doped and Hydrogen-Annealed Czochralski-Grown Silicon Wafers (United States)

    Goto, Hiroyuki; Pan, Lian-Sheng; Tanaka, Masafumi; Kashima, Kazuhiko


    The properties of nitrogen-doped and hydrogen-annealed Czochralski-grown silicon (NHA-CZ-Si) wafers were investigated in this study. The quality of the subsurface was investigated by monitoring the generation lifetime of minority carriers, as measured by the capacitance-time measurements of a metal oxide silicon capacitor (MOS C-t). The intrinsic gettering (IG) ability was investigated by determining the nickel concentration on the surface and in the subsurface as measured by graphite furnace atomic absorption spectrometry (GFAAS) after the wafer was deliberately contaminated with nickel. From the results obtained, the generation lifetimes of these NHA-CZ-Si wafers were determined to be almost the same as, or a little longer than those of epitaxial wafers, and the IG ability was proportional to the total volume of oxygen precipitates [i.e., bulk micro defects (BMDs)], which was influenced by the oxygen and nitrogen concentrations in the wafers. Therefore, it is suggested that the subsurface of the NHA-CZ-Si wafers is of good quality and the IG capacity is controllable by the nitrogen and oxygen concentrations in the wafers.

  8. Fast-ramp rapid vertical processor for 300-mm Si wafer processing (United States)

    Porter, Cole; Laser, Allan; Herring, Robert; Pandey, Pradeep


    Fast-ramp vertical furnace technology has been established on the 200-nm wafer platform providing higher capacity production, decreased cycle time and lower thermal budgets. Fast-ramp furnaces are capable of instantaneous temperature ramp rates up to 100 degrees C/min. This fast-ramp technology is now applied to 300-nm wafer processing on the SVG/Thermco Rapid Vertical Processor Vertical Furnace. 300- mm fast-ramp capability using the latest in real-time adaptive model based temperature control technology, Clairvoyant Control, is reported. Atmospheric Thermal Oxidation, LPCVD Nitride and Polysilicon Deposition, and LPCVD TEOS-based SiO2 Deposition results are discussed. 300- mm wafer Radial Delta Temperature dependence on temperature ramp rate, wafer pitch, and wafer support fixtures are discussed. Wafer throughput is calculated and reported. The Clairvoyant Control methodology of combining thermal, direct and virtually-sensed parameters to produce real-tim e estimation of wafer temperatures, thermal trajectory optimization, and feedback to minimize variations in film thickness and electrical properties is presented.

  9. Kerfless Silicon Precursor Wafer Formed by Rapid Solidification: October 2009 - March 2010

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, A.


    1366 Direct Wafer technology is an ultra-low-cost, kerfless method of producing crystalline silicon wafers compatible with the existing dominant silicon PV supply chain. By doubling utilization of silicon and simplifying the wafering process and equipment, Direct Wafers will support drastic reductions in wafer cost and enable module manufacturing costs < $1/W. This Pre-Incubator subcontract enabled us to accelerate the critical advances necessary to commercialize the technology by 2012. Starting from a promising concept that was initially demonstrated using a model material, we built custom equipment necessary to validate the process in silicon, then developed sufficient understanding of the underlying physics to successfully fabricate wafers meeting target specifications. These wafers, 50 mm x 50 mm x 200 thick, were used to make prototype solar cells via standard industrial processes as the project final deliverable. The demonstrated 10% efficiency is already impressive when compared to most thin films, but still offers considerable room for improvement when compared to typical crystalline silicon solar cells.

  10. Innovative metal thermo-compression wafer bonding for microelectronics and MEMS devices (United States)

    Rebhan, B.; Dragoi, V.


    With the continuously increasing level of integration for microelectronics and microelectromechanical systems (MEMS) devices, such as gyroscopes, accelerometers and bolometers, metal wafer bonding becomes progressively more importance. In the present work common metal wafer bonding techniques were categorized, described and compared. While devices produced with metal thermo-compression wafer bonding ensure high bonding quality and a high degree of reliability, the required bonding temperatures are very often close to the maximum complementary metal oxide semiconductor (CMOS) compatible process temperature (400-450°C). Based on a thermodynamic model of increasing the Gibbs free energy prior wafer bonding, in-situ ComBond(R) surface activation was applied to enable low-temperature Au-Au, Al-Al and Cu-Cu wafer bonding. Different aspects, such as bonding quality, dicing yield, bond strength, grain growth and elemental analysis across the initial bonding interface, were investigated. Based on these parameters successful wafer bonding was demonstrated at room temperature for Au-Au and Cu-Cu, and at 100°C for Al-Al wafer bonding.

  11. AWV: high-throughput cross-array cross-wafer variation mapping (United States)

    Yeo, Jeong-Ho; Lee, Byoung-Ho; Lee, Tae-Yong; Greenberg, Gadi; Meshulach, Doron; Ravid, Erez; Levi, Shimon; Kan, Kobi; Shabtay, Saar; Cohen, Yehuda; Rotlevi, Ofer


    Minute variations in advanced VLSI manufacturing processes are well known to significantly impact device performance and die yield. These variations drive the need for increased measurement sampling with a minimal impact on Fab productivity. Traditional discrete measurements such as CDSEM or OCD, provide, statistical information for process control and monitoring. Typically these measurements require a relatively long time and cover only a fraction of the wafer area. Across array across wafer variation mapping ( AWV) suggests a new approach for high throughput, full wafer process variation monitoring, using a DUV bright-field inspection tool. With this technique we present a full wafer scanning, visualizing the variation trends within a single die and across the wafer. The underlying principle of the AWV inspection method is to measure variations in the reflected light from periodic structures, under optimized illumination and collection conditions. Structural changes in the periodic array induce variations in the reflected light. This information is collected and analyzed in real time. In this paper we present AWV concept, measurements and simulation results. Experiments were performed using a DUV bright-field inspection tool (UVision (TM), Applied Materials) on a memory short loop experiment (SLE), Focus Exposure Matrix (FEM) and normal wafers. AWV and CDSEM results are presented to reflect CD variations within a memory array and across wafers.

  12. Processamento de Ligas de Níquel com Técnica de Manufatura Aditiva Utilizando Plasma por Arco Transferido


    Eduardo André Alberti; Bruno Machado Pereira Bueno; Ana Sofia C. M. D’Oliveira


    ResumoA manufatura aditiva é um processo utilizado para a construção e reparos de peças que possuem geometria complexa ou que necessitem de gradiente de propriedades. Nessa técnica múltiplas camadas são depositadas para a construção da geometria do componente. O sucesso desse procedimento depende de fatores como a técnica de deposição, parâmetros, liga a ser depositada e condições da deposição, como temperatura e atmosfera protetora. Neste estudo, o potencial da técnica de Plasma por arco tra...

  13. [As the twig is bent, so is the tree inclined: children and the Liga Brasileira de Higiene Mental's eugenic programs]. (United States)

    Reis, J R


    Created in the early 1920s, at a moment when the country's psychiatric field was embracing the preventive outlook, the Liga Brasileira de Higiene Mental included within its members the elite of Brazilian psychiatry, along with a number of physicians and intellectuals. The article discusses the institution's proposals for intervention among children. The league ended up incorporating into its theoretical arsenal the basic themes of mental hygiene and eugenics as part of its general goal of collaborating in Brazil's process of "racial sanitation". With this objective in mind, and viewing the child as a "pre-citizen" who is a "fundamental part within the man of the future", league members included the children's issue in their projects and saw an imperative need for mental health care from early ages on.

  14. Sheet resistance uniformity in drive-in step for different multi-crystalline silicon wafer dispositions

    Energy Technology Data Exchange (ETDEWEB)

    Moussi, A.; Bouhafs, D.; Mahiou, L. [Laboratoire des Cellules Photovoltaiques, Unite de Developpement de la Technologie du Silicium, 2 Bd, Frantz Fanon, B.P. 140, 7 Merveilles Alger (Algeria); Belkaid, M.S. [Dep. Electronique, Faculte de Genie Electrique et Informatique, UMMTO (Algeria)


    In this work, we present a study of emitters realized using different configurations of the silicon wafers in the quartz boat. The phosphorous liquid source is sprayed onto p-type multi-crystalline silicon substrates and the drive-in is made at high temperature in a muffle furnace. Three different configurations of the wafers in the boat are tested: separated, back to back and compact block of wafers. A fourth configuration is also used in source-receptor mode. The emitter phosphorous concentration profile is obtained by SIMS analysis. The resulting emitters are characterized by sheet resistance measurements and a comparison is made between the wafers within the same batch and from one batch to another. The uniformity and the standard deviation of the sheet resistance are calculated in each case. The emitter sheet resistance mapping of the wafer set in the middle of the boat for a given process gives a mean R{sub sq} 14.66 {omega}/sq with a standard deviation of 1.76% and uniformity of 18.7%. Standard deviations of 2.116% and 1.559% are obtained for wafers in the batch when using the spaced and compact configurations, respectively. The standard deviation is reduced to 0.68% when the wafers are used in source/receptor mode. A comparison is also made between wafers with different dilution of phosphorous source in ethanol. From these results we can conclude that the compact configuration offers better uniformity and lower standard deviation. Furthermore, when combined with the source-receptor configuration these parameters are significantly improved. This study allows the experimenter to identify the technological parameters of the solar cell emitter manufacturing and target precisely the desired values of the sheet resistance while limiting the number of rejected wafers. (author)


    Directory of Open Access Journals (Sweden)



    Full Text Available UV-LIGA es una técnica versátil que permite la fabricación de piezas metálicas con alta relación de aspecto (alto/ancho mediante la combinación del procesamiento fotolitográfico de un polímero y la electroformación de un metal al interior de las cavidades grabadas en el polímero. Esta técnica de bajo costo es empleada en una gran variedad de áreas que comprenden la microfluídica, la óptica, la instrumentación, el moldeado de plásticos y las telecomunicaciones, entre otras. Para aproximar a Colombia a estas tecnologías modernas de procesamiento de materiales, el Grupo de Ciencia y Tecnología de Materiales ha iniciado un proceso de apropiación de técnicas de microfabricación, específicamente, este artículo presenta los resultados de la implementación de la técnica UV-LIGA para la fabricación de micropiezas de Níquel y examina los efectos de la geometría del molde en la velocidad de crecimiento e integridad de los depósitos obtenidos, parámetros que sonimportantes para conseguir la fabricación de piezas micrométricas complejas que den origen a dispositivos con aplicaciones comerciales.

  16. Electronic properties of interfaces produced by silicon wafer hydrophilic bonding

    Energy Technology Data Exchange (ETDEWEB)

    Trushin, Maxim


    The thesis presents the results of the investigations of electronic properties and defect states of dislocation networks (DNs) in silicon produced by wafers direct bonding technique. A new insight into the understanding of their very attractive properties was succeeded due to the usage of a new, recently developed silicon wafer direct bonding technique, allowing to create regular dislocation networks with predefined dislocation types and densities. Samples for the investigations were prepared by hydrophilic bonding of p-type Si (100) wafers with same small misorientation tilt angle ({proportional_to}0.5 ), but with four different twist misorientation angles Atw (being of < , 3 , 6 and 30 , respectively), thus giving rise to the different DN microstructure on every particular sample. The main experimental approach of this work was the measurements of current and capacitance of Schottky diodes prepared on the samples which contained the dislocation network at a depth that allowed one to realize all capabilities of different methods of space charge region spectroscopy (such as CV/IV, DLTS, ITS, etc.). The key tasks for the investigations were specified as the exploration of the DN-related gap states, their variations with gradually increasing twist angle Atw, investigation of the electrical field impact on the carrier emission from the dislocation-related states, as well as the establishing of the correlation between the electrical (DLTS), optical (photoluminescence PL) and structural (TEM) properties of DNs. The most important conclusions drawn from the experimental investigations and theoretical calculations can be formulated as follows: - DLTS measurements have revealed a great difference in the electronic structure of small-angle (SA) and large-angle (LA) bonded interfaces: dominating shallow level and a set of 6-7 deep levels were found in SA-samples with Atw of 1 and 3 , whereas the prevalent deep levels - in LA-samples with Atw of 6 and 30 . The critical twist

  17. Characterization of perovskite layer on various nanostructured silicon wafer (United States)

    Rostan, Nur Fairuz Mohd; Sepeai, Suhaila; Ramli, Noor Fadhilah; Azhari, Ayu Wazira; Ludin, Norasikin Ahmad; Teridi, Mohd Asri Mat; Ibrahim, Mohd Adib; Zaidi, Saleem H.


    Crystalline silicon (c-Si) solar cell dominates 90% of photovoltaic (PV) market. The c-Si is the most mature of all PV technologies and expected to remain leading the PV technology by 2050. The attractive characters of Si solar cell are stability, long lasting and higher lifetime. Presently, the efficiency of c-Si solar cell is still stuck at 25% for one and half decades. Tandem approach is one of the attempts to improve the Si solar cell efficiency with higher bandgap layer is stacked on top of Si bottom cell. Perovskite offers a big potential to be inserted into a tandem solar cell. Perovskite with bandgap of 1.6 to 1.9 eV will be able to absorb high energy photons, meanwhile c-Si with bandgap of 1.124 eV will absorb low energy photons. The high carrier mobility, high carrier lifetime, highly compatible with both solution and evaporation techniques makes perovskite an eligible candidate for perovskite-Si tandem configuration. The solution of methyl ammonium lead iodide (MAPbI3) was prepared by single step precursor process. The perovskite layer was deposited on different c-Si surface structure, namely planar, textured and Si nanowires (SiNWs) by using spin-coating technique at different rotation speeds. The nanostructure of Si surface was textured using alkaline based wet chemical etching process and SiNW was grown using metal assisted etching technique. The detailed surface morphology and absorbance of perovskite were studied in this paper. The results show that the thicknesses of MAPbI3 were reduced with the increasing of rotation speed. In addition, the perovskite layer deposited on the nanostructured Si wafer became rougher as the etching time and rotation speed increased. The average surface roughness increased from ˜24 nm to ˜38 nm for etching time range between 5-60 min at constant low rotation speed (2000 rpm) for SiNWs Si wafer.

  18. Enhanced photoluminescence from photonic crystal-coated GaN LED wafers (United States)

    Rahman, F.; Khokhar, A. Z.


    This paper describes results of studies on photoluminescence from blue-emitting GaN LED wafers coated with a layer of synthetic opal photonic crystals. Commercial LED wafer material was used and samples were coated with thin films consisting of several layers of stacked spherical polystyrene balls. Various optical measurements were performed on these samples while they were excited with a 405 nm laser beam. Diffraction pattern due to the photonic crystal structure, showing the underlying six-fold symmetry, was recorded. The spectrum and angle-resolved intensity of photoluminescence were measured to understand the coupling of LED light with the grown photonic crystal structure on top of the wafer.

  19. 1366 Project Automate: Enabling Automation for <$0.10/W High-Efficiency Kerfless Wafers Manufactured in the US

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, Adam [1366 Technologies, Bedford, MA (United States)


    For photovoltaic (PV) manufacturing to thrive in the U.S., there must be an innovative core to the technology. Project Automate builds on 1366’s proprietary Direct Wafer® kerfless wafer technology and aims to unlock the cost and efficiency advantages of thin kerfless wafers. Direct Wafer is an innovative, U.S.-friendly (efficient, low-labor content) manufacturing process that addresses the main cost barrier limiting silicon PV cost-reductions – the 35-year-old grand challenge of manufacturing quality wafers (40% of the cost of modules) without the cost and waste of sawing. This simple, scalable process will allow 1366 to manufacture “drop-in” replacement wafers for the $10 billion silicon PV wafer market at 50% of the cost, 60% of the capital, and 30% of the electricity of conventional casting and sawing manufacturing processes. This SolarMat project developed the Direct Wafer processes’ unique capability to tailor the shape of wafers to simultaneously make thinner AND stronger wafers (with lower silicon usage) that enable high-efficiency cell architectures. By producing wafers with a unique target geometry including a thick border (which determines handling characteristics) and thin interior regions (which control light capture and electron transport and therefore determine efficiency), 1366 can simultaneously improve quality and lower cost (using less silicon).

  20. Adhesive disbond detection using piezoelectric wafer active sensors (United States)

    Roth, William; Giurgiutiu, Victor


    The aerospace industry continues to increase the use of adhesives for structural bonding due to the increased joint efficiency (reduced weight), even distribution of the load path and decreases in stress concentrations. However, the limited techniques for verifying the strength of adhesive bonds has reduced its use on primary structures and requires an intensive inspection schedule. This paper discusses a potential structural health monitoring (SHM) technique for the detection of disbonds through the in situ inspection of adhesive joints. This is achieved through the use of piezoelectric wafer active sensors (PWAS), thin unobtrusive sensors which are permanently bonded to the aircraft structure. The detection method discussed in this study is electromechanical impedance spectroscopy (EMIS), a local vibration method. This method detects disbonds from the change in the mechanical impedance of the structure surrounding the disbond. This paper will discuss how predictive modeling can provide valuable insight into the inspection method, and provide better results than empirical methods alone. The inspection scheme was evaluated using the finite element method, and the results were verified experimentally using a large aluminum test article, and included both pristine and disbond coupons.

  1. Proton irradiation effects on the properties of silicon wafer

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Gihyun; Shin, Chansun [Myongji University, Yongin (Korea, Republic of); Sun, Gwang-Min [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)


    The study the effect of energetic particle irradiation on the properties of semiconductor devices has been interested for developing and utilizing semiconductor irradiation detectors under various irradiation conditions such as large hadron collider in CERN. In this study, we investigated the influence of proton irradiation on carrier lifetime and electrical resistance of silicon wafers. Proton is known to make a stable irradiation defects in silicon. These irradiation defects form a new energy level within the band gap, hence affect the properties of silicon. The irradiation defects generated by proton irradiation affect the carrier lifetime by capturing excess carriers and the electrical resistance by hindering the carrier movement. In this study, the carrier lifetime of proton-irradiated silicon substrates was found to decrease rapidly as the irradiation dose increases. On the other hand, the sheet electrical resistance was not significantly changed up to the irradiation dose level of 10{sup 12} cm{sup -2}. Hence, proton irradiation less than dose level of 10{sup 12} cm{sup -2} can be utilized to decrease carrier lifetime significantly without sacrificing the electrical resistance.

  2. The surface leakage currents of CdZnTe wafers

    Energy Technology Data Exchange (ETDEWEB)

    Zha Gangqiang [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China)]. E-mail:; Jie Wanqi [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Tan Tingting [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China); Li Peisen [School of Materials Science and Engineering, Northwestern Polytechnical University, Xi' an 710072 (China)


    The surface leakage currents (SLCs) and surface sheet resistances (SSRs) of CdZnTe (1 1 0) (1 1 1) A and (1 1 1) B surfaces after etching with Br-MeOH solution, chemo-mechanical polishing (CMP) and passivation were measured in the parallel stripe model, respectively. Meanwhile the surface compositions were determined by X-ray photoelectron spectroscopy (XPS). Te enrichment introduced by etching with Br-MeOH resulted in the increase of the SLCs of CdZnTe wafers. After chemo-mechanical polishing, Te enrichment was removed, and SLCs decreased. CdZnTe (1 1 1) B without Te enrichment possesses higher SLC than that of (1 1 1) A, and (1 1 0) surface has the lowest SLC, which should be attributed to the lower surface dangling bonds. Passivation treatment with NH{sub 4}F + H{sub 2}O{sub 2} is an effective method to decrease SLCs of CdZnTe, by which the SLC was decreased two orders.

  3. Low Loss, Finite Width Ground Plane, Thin Film Microstrip Lines on Si Wafers (United States)

    Ponchak, George E.; Margomenos, Alexandros; Katehi, Linda P. B.


    Si RFICs on standard, 2 Omega-cm. Si wafers require novel transmission lines to reduce the loss caused by the resistive substrate. One such transmission line is commonly called Thin Film Microstrip (TFMS), which is created by depositing a metallic ground plane, thin insulating layers, and the microstrip lines on the Si wafer. Thus, the electric fields are isolated from the Si wafer. In this paper, it is shown through experimental results that the ground plane of TFMS may be finite width and comparable to the strip width in size while still achieving low loss on 2 Omega-cm Si. Measured effective permittivity shows that the field interaction with the Si wafer is small.

  4. A study of defects on EUV mask using blank inspection, patterned mask inspection, and wafer inspection

    Energy Technology Data Exchange (ETDEWEB)

    Huh, S.; Ren, L.; Chan, D.; Wurm, S.; Goldberg, K. A.; Mochi, I.; Nakajima, T.; Kishimoto, M.; Ahn, B.; Kang, I.; Park, J.-O.; Cho, K.; Han, S.-I.; Laursen, T.


    The availability of defect-free masks remains one of the key challenges for inserting extreme ultraviolet lithography (EUVL) into high volume manufacturing. yet link data is available for understanding native defects on real masks. In this paper, a full-field EUV mask is fabricated to investigate the printability of various defects on the mask. The printability of defects and identification of their source from mask fabrication to handling were studied using wafer inspection. The printable blank defect density excluding particles and patterns is 0.63 cm{sup 2}. Mask inspection is shown to have better sensitivity than wafer inspection. The sensitivity of wafer inspection must be improved using through-focus analysis and a different wafer stack.

  5. Hydrogen-induced program threshold voltage degradation analysis in SONOS wafer (United States)

    Lin, Qing; Zhao, Crystal; Sheng, Nan


    This paper studies the hydrogen-induced program state threshold voltage degradation in SONOS wafers, which ultimately impacts wafer sort test yield. During wafer sort step, all individual integrated circuits noted as die are tested for functional defects by applying special test patterns to them. The proportion between the passing die (good die) and the non-passing die (bad die) is sort yield. The different N2/H2 ratio in IMD1 alloy process yields differently at flash checkerboard test. And the SIMS curves were also obtained to depict the distribution profile of H+ in SONOS ONO stack structure. It is found that, the H+ accumulated in the interface between the Tunnel oxide and Si layer, contributes the charge loss in Oxynitride layer, which leads to the program threshold voltage degradation and even fall below lower specification limit, and then impacts the sort yield of SONOS wafers.

  6. High uniform growth of 4-inch GaN wafer via flow field optimization by HVPE (United States)

    Cheng, Yutian; Liu, Peng; Wu, Jiejun; Xiang, Yong; Chen, Xinjuan; Ji, Cheng; Yu, Tongjun; Zhang, Guoyi


    The uniformity of flow field inner the reactor plays a crucial role for hydride vapor phase epitaxy (HVPE) crystal growth and its more important for large scale substrate. A new nozzle structure was designed by adding a push and dilution (PD) gas pipe in the center of gas channels for a 4-inch HVPE (PD-HVPE) system. Experimental results showed that the thickness inhomogeneity of 46 μm 4-inch GaN layer could reach ±1.8% by optimizing PD gas, greatly improved from ±14% grown with conventional nozzle. The simulations of the internal flow field were consistent with our experiment, and the enhancement in uniformity should be attributed to the redistribution of GaCl and NH3 upon the wafer induced by PD pipe. The full width at half maximum (FWHM) of X-ray diffraction rocking curves for the 4-inch GaN film were about 224 and 200 arcsec for (002) and (102) reflection. The dislocation density of as-grown GaN was about 6.4×107 cm-2.

  7. Silicon wafer wettability and aging behaviors: Impact on gold thin-film morphology

    KAUST Repository

    Yang, Xiaoming


    This paper reports on the wettability and aging behaviors of the silicon wafers that had been cleaned using a piranha (3:1 mixture of sulfuric acid (H2SO4, 96%) and hydrogen peroxide (H2O 2, 30%), 120 °C), SC1 (1:1:5 mixture of NH4OH, H 2O2 and H2O, at 80°C) or HF solution (6 parts of 40% NH4F and 1 part of 49% HF, at room temperature) solution, and treated with gaseous plasma. The silicon wafers cleaned using the piranha or SC1 solution were hydrophilic, and the water contact angles on the surfaces would increase along with aging time, until they reached the saturated points of around 70°. The contact angle increase rate of these wafers in a vacuum was much faster than that in the open air, because of loss of water, which was physically adsorbed on the wafer surfaces. The silicon wafers cleaned with the HF solution were hydrophobic. Their contact angle decreased in the atmosphere, while it increased in the vacuum up to 95°. Gold thin films deposited on the hydrophilic wafers were smoother than that deposited on the hydrophobic wafers, because the numerous oxygen groups formed on the hydrophilic surfaces would react with gold adatoms in the sputtering process to form a continuous thin film at the nucleation stage. The argon, nitrogen, oxygen gas plasma treatments could change the silicon wafer surfaces from hydrophobic to hydrophilic by creating a thin (around 2.5 nm) silicon dioxide film, which could be utilized to improve the roughness and adhesion of the gold thin film. © 2014 Elsevier Ltd. All rights reserved.

  8. A 40 nm body-tied FinFET (OMEGA MOSFET) using bulk Si wafer (United States)

    Park, Tai-su; Yoon, Euijoon; Lee, Jong-Ho


    A new body-tied FinFET is proposed and fabricated on bulk Si wafer instead of SOI wafer. Three-dimensional device simulations show the characteristics of the proposed device and show that it can be implemented without deteriorating short channel effect. An active fin width of 25- 40 nm and a gate length of 40 nm were realized by using sidewall spacer technology.

  9. Improved consumer properties of wafers using non-traditional raw materials


    Лозовая, Татьяна Михайловна


    An urgent problem of increasing nutritional and biological value of wafers with fatty fillings, formulae of which include non-traditional raw materials is set forth, and some results of our studies are given. The main purpose of the research is to justify the possibility and feasibility of using natural non-traditional raw materials in the production of wafers. For these studies, organoleptic characteristics, nutritional value, amino acid, fatty acid, mineral and vitamin composition, clinical...

  10. Impact of laser treatment on phosphoric acid coated multicrystalline silicon PV-wafers


    Geier, M.; Eberstein, M.; Grießmann, H.; Partsch, U.; Völkel, L.; Böhme, R; Mann, G.; Bonse, J.; Krüger, J


    The selective emitter is a well-known technology for producing highly doped areas under the metallization grid to improve the solar cell performance. In this work, the influence of laser irradiation on phosphoric acid coated multicrystalline silicon PV-wafers on the wafer surface structure, the phosphorous depth distribution and the electrical contact resistance within the laser treated area as well as the electrical series resistance of laserprocessed solar cells was evaluated. Different las...

  11. In vitro and in vivo evaluation of a sublingual fentanyl wafer formulation (United States)

    Lim, Stephen CB; Paech, Michael J; Sunderland, Bruce; Liu, Yandi


    Background The objective of this study was to prepare a novel fentanyl wafer formulation by a freeze-drying method, and to evaluate its in vitro and in vivo release characteristics, including its bioavailability via the sublingual route. Methods The wafer formulation was prepared by freeze-drying an aqueous dispersion of fentanyl containing sodium carboxymethylcellulose and amylogum as matrix formers. Uniformity of weight, friability, and dissolution testing of the fentanyl wafer was achieved using standard methods, and the residual moisture content was measured. The fentanyl wafer was also examined using scanning electron microscopy and x-ray diffraction. The absolute bioavailability of the fentanyl wafer was evaluated in 11 opioid-naïve adult female patients using a randomized crossover design. Results In vitro release showed that almost 90% of the fentanyl dissolved in one minute. In vivo, the first detectable plasma fentanyl concentration was observed after 3.5 minutes and the peak plasma concentration between 61.5 and 67 minutes. The median absolute bioavailability was 53.0%. Conclusion These results indicate that this wafer has potential as an alternative sublingual fentanyl formulation. PMID:23596347

  12. The integration of InGaP LEDs with CMOS on 200 mm silicon wafers (United States)

    Wang, Bing; Lee, Kwang Hong; Wang, Cong; Wang, Yue; Made, Riko I.; Sasangka, Wardhana Aji; Nguyen, Viet Cuong; Lee, Kenneth Eng Kian; Tan, Chuan Seng; Yoon, Soon Fatt; Fitzgerald, Eugene A.; Michel, Jurgen


    The integration of photonics and electronics on a converged silicon CMOS platform is a long pursuit goal for both academe and industry. We have been developing technologies that can integrate III-V compound semiconductors and CMOS circuits on 200 mm silicon wafers. As an example we present our work on the integration of InGaP light-emitting diodes (LEDs) with CMOS. The InGaP LEDs were epitaxially grown on high-quality GaAs and Ge buffers on 200 mm (100) silicon wafers in a MOCVD reactor. Strain engineering was applied to control the wafer bow that is induced by the mismatch of coefficients of thermal expansion between III-V films and silicon substrate. Wafer bonding was used to transfer the foundry-made silicon CMOS wafers to the InGaP LED wafers. Process trenches were opened on the CMOS layer to expose the underneath III-V device layers for LED processing. We show the issues encountered in the 200 mm processing and the methods we have been developing to overcome the problems.

  13. Los orígenes de la Cuarta Internacional en Argentina. El caso del Grupo Obrero Revolucionario y La Liga Obrera Revolucionaria

    Directory of Open Access Journals (Sweden)

    Constanza Daniela Bosch Alessio


    Full Text Available A fines de 1938 Liborio Justo se alejó del Partido Socialista Obrero para formar su propia organización trotskista junto a Aquiles Garmendia, Esteban Rey, Reinaldo Frigerio y Mateo Fossa: el Grupo Obrero Revolucionario (GOR. El GOR impulsó entre 1938 y 1940 la publicación de una serie de folletos bajo el sello “Acción Obrera” y la edición del periódico La Internacional. Tras una fallida unificación con la Liga Obrera Socialista –el grupo trotskista de Antonio Gallo-, el GOR se transformó en 1941 en la Liga Obrera Revolucionaria (LOR. Sin embargo, las constantes disputas internas entre sus ya escasos militantes, acabaron por vaciar de sentido la continuidad de la agrupación en 1943.

  14. Micro-nano photonic biosensors scalable at the wafer level (United States)

    Holgado, M.; Casquel, R.; Lagunas, María-Fe


    We present a potential high sensitive label-free optical bio-sensing system based on biophotonic sensing cells, which can be fabricated and interrogated at wafer or disposable chip level. The key benefits rely on the holistic approach that combines bio-photonic resonant micro-nano cavities and advanced sub-micron spot size optical interrogation technologies. The proposed optical sensing system will be tremendously sensitive to refractive index variations by means of the observation of the reflectivity profile of three complementary enhanced sub-micron spot size optical technologies simultaneously (Reflectometry, Spectrometry and Ellipsometry based techniques), and the magnification due to the biophotonics resonant sensing cells, making possible to determine with more reliability and sensitivity the biomolecular interaction with the receptor biomolecules. This novel sensing system also offers an inexpensive solution for integration and packaging because it overcomes the need for using complex systems for light coupling such as inverted tapers or grating couplers, usually used in planar micro-nano photonic devices, because the sensor evaluation is done measuring vertically collecting the reflected light of the bio-photonic resonant sensing cells. The sensing system may use a tightly focused beam which allows measuring in situ micron/sub-micron size geometries, making the routine screening more cost-effective and suitable to perform hundreds of measurements on a single or several samples for multi-single or multiparameter measurements. The simultaneous used of the three different optical techniques will allow the systems to achieve a high throughput and productivity in comparison with other established analytical techniques. The levels of sensitivity expected are in the order of 10-6/10-7 refractive index units (RIU).

  15. Application of high frequency bipolar electrocoagulation LigaSureTM in appendix vermiformis of rabbits with or without acute inflammatory process Aplicação do eletrocoagulador bipolar de alta frequência LigaSureTM no apêndice vermiforme na vigência ou não de processo inflamatório agudo

    Directory of Open Access Journals (Sweden)

    Laura Cristina de Souza


    Full Text Available PURPOSE: To evaluate the efficacy of the use of LigaSureTM in appendectomy, with or without acute inflammatory process, and to compare with simple ligature and conventional therapy. METHODS: A total of 30 rabbits (Oryctolagus cuniculus randomly allocated in two groups, group A and B, of 15 animals each were used. The group A without acute appendicitis and the group B with acute appendicitis were submitted to appendectomy. After, the groups were subdivided into three groups, each group containing five rabbits submitted to simple ligature, conventional therapy and application of LigaSureTM. We assessed macroscopic and microscopy parameters of appendiceal stump and operative wound. RESULTS: The group with acute appendicitis that LigaSureTM was applied had fibrosis in 100% of animals, as well as in the other operative techniques used. It suggested that application of LigaSureTM is efficient as other techniques used in healing of appendiceal stump. CONCLUSIONS: The application of LigaSureTM induces the formation of fibrosis in the appendiceal stump. The technique proved efficacy to induce enough fibrous tissue to obstruct leakage of enteric content.OBJETIVO: Avaliar a eficácia da utilização do LigaSureTM na apendicectomia, com ou sem a presença de processo inflamatório agudo, comparando com ligadura simples ou técnica tradicional. MÉTODOS: Um total de 30 coelhos (Oryctolagus cuniculus foi alocado em dois grupos, grupos A e B, cada um composto por 15 animais. O grupo A não apresentava apendicite aguda e o grupo B com apendicite aguda, sendo os animais submetidos à apendicitectomia. Cada grupo foi divido em três subgrupos, cada um com cinco animais onde foram então submetidos à ligadura simples, técnica tradicional ou utilização do LigaSureTM. Foram avaliados parâmetros macroscópicos assim como microscópicos do coto apendicular assim como da ferida operatória. RESULTADOS: No grupo que apresentava apendicite aguda onde foi utilizado o

  16. La incertidumbre de los resultados en las ligas española, inglesa e italiana (2008/09 mediante el rating ELO

    Directory of Open Access Journals (Sweden)

    Sala Garrido, Ramon


    Full Text Available RESUMEN En numerosas ocasiones se discute si una determinada liga es la mejor de Europa o si es otra, pero muchas veces ese concepto de “mejor” queda indefinido y se basa en elementos subjetivos o apreciaciones. El objetivo de este trabajo es comparar las ligas, española, inglesa e italiana, utilizando el rating ELO para poder determinar cual de las ligas es más homogénea en términos de equilibrio entre los equipos.El interés de una liga depende en gran parte de que exista incertidumbre en el resultado, es decir, lo que viene a denominarse como balance competitivo entre los equipos que la forman, ya que si no es así, la competición pierde interés en la medida en que el resultado es demasiado prfevisible, es decir, que los “buenos” equipos siempre vencen a los restantes, con lo que se perjudica al espectáculo y por tanto, las ganancias que reportan los ingresos, especialmente los televisivos.ABSTRACT It is often discussed whether a particular football league (soccer in America is the best league. However, the term 'best' is often indefinite and based on subjective elements. The aim of this study is to compare the Spanish, English and Italian leagues by using the ELO rating system to determine which league is more homogeneous in terms of balance between the teams. The level of interest in a league largely depends on the uncertainty of outcome or the competitive balance between the teams. If there is a competitive imbalance between the teams then the competition loses interest because the expected results coincide with the real results, namely the 'top' teams always win against the others. This can damage the spectacle, and therefore the earnings produced – especially in the case of television.

  17. Toxicidade e capacidade de ligação de proteínas Cry1 a receptores intestinais de Helicoverpa armigera (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Isis Sebastião


    Full Text Available Resumo: O objetivo deste trabalho foi avaliar a toxicidade e a capacidade de ligação das proteínas Cry1Aa, Cry1Ab, Cry1Ac e Cry1Ca, de Bacillus thuringiensis, a receptores intestinais de Helicoverpa armigera. Realizou-se análise de ligação das proteínas ativadas às vesículas de membrana da microvilosidade apical (VMMA do intestino médio deH. armigera, além de ensaios de competição heteróloga para avaliar sua capacidade de ligação. Cry1Ac destacou-se como a proteína mais tóxica, seguida por Cry1Ab e Cry1Aa. A proteína Cry1Ca não foi tóxica às lagartas e, portanto, não foi possível determinar os seus parâmetros de toxicidade CL50 e CL90. As proteínas Cry1Aa, Cry1Ab e Cry1Ac são capazes de se ligar a um mesmo receptor nas membranas intestinais, o que aumenta o risco do desenvolvimento de resistência cruzada. Portanto, a utilização conjunta dessas proteínas deve ser evitada.

  18. Konsumsi karbohidrat dan lemak dan hubungannya dengan daya tahan jantung paru atlet sepak bola PS Semen Padang Divisi Utama PSSI Liga Bank Mandiri IX tahun 2003

    Directory of Open Access Journals (Sweden)

    Ferry Ferry


    Full Text Available Background: Football is body movement that need energy balanced for maintaining optimum cardiorespiratory endurance. Macronutrient and micronutrient are the most nutrient needed to produce energy so that athletes have maximal performance in each sport activity. Athlete’s menu must be consist of 60-70% carbohydrate and 20-25% fat of total energy. Objective: To find out the correlation between the pattern of carbohydrate and fat intake with cardiorespiratory endurance of football athletes of PS Semen Padang in the top division of PSSI Liga Bank Mandiri in 2003. Method: This research was observational with cross sectional design. The subjects were football athletes of PS Semen Padang in the top division of PSSI Liga Bank Mandiri in 2003. Variables consisted of the pattern of carbohydrate and  fat intake, and cardiorespiratory endurance. Data were analysed using univariate, bivariate, and multivariate analysis. Results: There were no significant correlation between carbohydrate (p=0.751 and fat (p=0.297 intake with cardio- respiratory endurance, while BMI (p=0.034, triglyceride (p=0.044 and body fat (p=0.007 had significant correlation with cardiorspiratory endurance. The most influential variable to cardiorespiratory endurance was body fat (OR=12.00. Conclusion: There were significant correlation between BMI, triglyceride, and body fat with cardiorespiratory endurance of football athletes of PS Semen Padang in the top division of PSSI Liga Bank Mandiri in 2003, but  there was no correlation between pattern of carbohydrate and fat intake with cardiorespiratory endurance.

  19. The terminal portion of leptospiral immunoglobulin-like protein LigA confers protective immunity against lethal infection in the hamster model of leptospirosis. (United States)

    Silva, Everton F; Medeiros, Marco A; McBride, Alan J A; Matsunaga, Jim; Esteves, Gabriela S; Ramos, João G R; Santos, Cleiton S; Croda, Júlio; Homma, Akira; Dellagostin, Odir A; Haake, David A; Reis, Mitermayer G; Ko, Albert I


    Subunit vaccines are a potential intervention strategy against leptospirosis, which is a major public health problem in developing countries and a veterinary disease in livestock and companion animals worldwide. Leptospiral immunoglobulin-like (Lig) proteins are a family of surface-exposed determinants that have Ig-like repeat domains found in virulence factors such as intimin and invasin. We expressed fragments of the repeat domain regions of LigA and LigB from Leptospira interrogans serovar Copenhageni. Immunization of Golden Syrian hamsters with Lig fragments in Freund's adjuvant induced robust antibody responses against recombinant protein and native protein, as detected by ELISA and immunoblot, respectively. A single fragment, LigANI, which corresponds to the six carboxy-terminal Ig-like repeat domains of the LigA molecule, conferred immunoprotection against mortality (67-100%, P<0.05) in hamsters which received a lethal inoculum of L. interrogans serovar Copenhageni. However, immunization with this fragment did not confer sterilizing immunity. These findings indicate that the carboxy-terminal portion of LigA is an immunoprotective domain and may serve as a vaccine candidate for human and veterinary leptospirosis.

  20. High aspect ratio nano-fabrication of photonic crystal structures on glass wafers using chrome as hard mask. (United States)

    Hossain, Md Nazmul; Justice, John; Lovera, Pierre; McCarthy, Brendan; O'Riordan, Alan; Corbett, Brian


    Wafer-scale nano-fabrication of silicon nitride (Si x N y ) photonic crystal (PhC) structures on glass (quartz) substrates is demonstrated using a thin (30 nm) chromium (Cr) layer as the hard mask for transferring the electron beam lithography (EBL) defined resist patterns. The use of the thin Cr layer not only solves the charging effect during the EBL on the insulating substrate, but also facilitates high aspect ratio PhCs by acting as a hard mask while deep etching into the Si x N y . A very high aspect ratio of 10:1 on a 60 nm wide grating structure has been achieved while preserving the quality of the flat top of the narrow lines. The presented nano-fabrication method provides PhC structures necessary for a high quality optical response. Finally, we fabricated a refractive index based PhC sensor which shows a sensitivity of 185 nm per RIU.

  1. In vitro and in vivo evaluation of a sublingual fentanyl wafer formulation

    Directory of Open Access Journals (Sweden)

    Lim SCB


    Full Text Available Stephen CB Lim,1,3 Michael J Paech,2 Bruce Sunderland,3 Yandi Liu3 1Pharmacy Department, Armadale Health Service, Armadale, 2School of Medicine and Pharmacology, University of Western Australia, and Department of Anaesthesia and Pain Medicine, King Edward Memorial Hospital for Women, Subiaco, 3School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Perth, WA, Australia Background: The objective of this study was to prepare a novel fentanyl wafer formulation by a freeze-drying method, and to evaluate its in vitro and in vivo release characteristics, including its bioavailability via the sublingual route. Methods: The wafer formulation was prepared by freeze-drying an aqueous dispersion of fentanyl containing sodium carboxymethylcellulose and amylogum as matrix formers. Uniformity of weight, friability, and dissolution testing of the fentanyl wafer was achieved using standard methods, and the residual moisture content was measured. The fentanyl wafer was also examined using scanning electron microscopy and x-ray diffraction. The absolute bioavailability of the fentanyl wafer was evaluated in 11 opioid-naïve adult female patients using a randomized crossover design. Results: In vitro release showed that almost 90% of the fentanyl dissolved in one minute. In vivo, the first detectable plasma fentanyl concentration was observed after 3.5 minutes and the peak plasma concentration between 61.5 and 67 minutes. The median absolute bioavailability was 53.0%. Conclusion: These results indicate that this wafer has potential as an alternative sublingual fentanyl formulation. Keywords: absolute bioavailability, fentanyl wafer, in vitro dissolution, in vivo study, pharmacokinetics, sublingual

  2. Behavior of piezoelectric wafer active sensor in various media (United States)

    Kamas, Tuncay

    The dissertation addresses structural health monitoring (SHM) techniques using ultrasonic waves generated by piezoelectric wafer active sensors (PWAS) with an emphasis on the development of theoretical models of standing harmonic waves and guided waves. The focal objective of the research is to extend the theoretical study of electro-mechanical coupled PWAS as a resonator/transducer that interacts with standing and traveling waves in various media through electro-mechanical impedance spectroscopy (EMIS) method and guided wave propagation. The analytical models are developed and the coupled field finite element analysis (CF-FEA) models are simulated and verified with experiments. The dissertation is divided into two parts with respect to the developments in EMIS methods and GWP methods. In the first part, analytical and finite element models have been developed for the simulation of PWAS-EMIS in in-plane (longitudinal) and out-of-plane (thickness) mode. Temperature effects on free PWAS-EMIS are also discussed with respect to the in-plane mode. Piezoelectric material degradation on certain electrical and mechanical properties as the temperature increases is simulated by our analytical model for in-plane circular PWAS-EMIS that agrees well with the sets of experiments. Then the thickness mode PWAS-EMIS model was further developed for a PWAS resonator bonded on a plate-like structure. The latter analytical model was to determine the resonance frequencies for the normal mode expansion method through the global matrix method by considering PWAS-substrate and proof mass-PWAS-substrate models. The proof mass concept was adapted to shift the systems resonance frequencies in thickness mode. PWAS in contact with liquid medium on one of its surface has been analytically modeled and simulated the electro-mechanical response of PWAS with various liquids with different material properties such as the density and the viscosity. The second part discusses the guided wave propagation

  3. Dedo robótico acionado por molas de liga com memória de forma

    Directory of Open Access Journals (Sweden)

    André Fellipe Cavalcante Silva


    Full Text Available A reabilitação robótica vem recebendo destaque nos últimos anos por suas pesquisas relevantes na busca de dirimir problemas relacionados a pessoas que sofreram alguma amputação ou que necessitam melhorar suas capacidades motoras. Este trabalho apresenta o projeto de um dedo artificial, baseado parcialmente na fisiologia humana, na busca de contribuir para a solução de problemas citados por pesquisadores envolvidos com a reabilitação robótica, assim como por pacientes que necessitam de próteses convencionais. O protótipo desenvolvido foi fabricado em plástico ABS, usando uma impressora tridimensional de prototipagem rápida. O movimento de flexão do dedo foi realizado por molas de uma Liga com Memória de Forma (LMF de Ni-Ti, ativados por aquecimento resistivo. Os testes realizados mostraram resultados relevantes aos encontrados na literatura internacional para dedos biométricos desenvolvidos com tecnologia semelhante, baseada em LMF.

  4. An Integrated Microfabricated Chip with Double Functions as an Ion Source and Air Pump Based on LIGA Technology

    Directory of Open Access Journals (Sweden)

    Hua Li


    Full Text Available The injection and ionization of volatile organic compounds (VOA by an integrated chip is experimentally analyzed in this paper. The integrated chip consists of a needle-to-cylinder electrode mounting on the Polymethyl Methacrylate (PMMA substrate. The needle-to-cylinder electrode is designed and fabricated by Lithographie, Galvanoformung and Abformung (LIGA technology. In this paper, the needle is connected to a negative power supply of −5 kV and used as the cathode; the cylinder electrodes are composed of two arrays of cylinders and serve as the anode. The ionic wind is produced based on corona and glow discharges of needle-to-cylinder electrodes. The experimental setup is designed to observe the properties of the needle-to-cylinder discharge and prove its functions as an ion source and air pump. In summary, the main results are as follows: (1 the ionic wind velocity produced by the chip is about 0.79 m/s at an applied voltage of −3300 V; (2 acetic acid and ammonia water can be injected through the chip, which is proved by pH test paper; and (3 the current measured by a Faraday cup is about 10 pA for acetic acid and ammonia with an applied voltage of −3185 V. The integrated chip is promising for portable analytical instruments, such as ion mobility spectrometry (IMS, field asymmetric ion mobility spectrometry (FAIMS, and mass spectrometry (MS.

  5. Resistência de união entre liga de níquel-cromo e cimentos resinosos

    Directory of Open Access Journals (Sweden)

    FRANÇA Rodrigo de Oliveira


    Full Text Available O objetivo do trabalho foi a determinação da retentividade, por ensaio de tração, entre uma liga de níquel-cromo e cimentos resinosos (Comspan, Panavia Ex e All-Bond C & B, com quatro tratamentos superficiais (liso, microjateado, ataque eletrolítico e silicoater e armazenagem por 3 e 30 dias em solução de NaCl a 0,9%, a 37° C e termociclagem intercalada na segunda (a 5 e 55° C, por 1 minuto em cada banho, perfazendo 600 ciclos. Os corpos de prova eram discos, providos de alça fixadora entre si dois a dois. Os resultados permitiram concluir que: superfícies lisas conduzem a baixíssimas retentividades e tratadas com silicoater a altíssimos valores, com qualquer cimento e condição de armazenagem; Panavia Ex com superfícies microjateadas também conduz a altas retentividades; a maior retentividade foi obtida pela combinação silicoater/All-Bond C&B.

  6. Should We Analyze for Trace Metal Contamination at the Edge, Bevel, and Edge Exclusion of Wafers? (United States)

    Beebe, Meredith; Sparks, Chris; Carpio, Ron


    The edge, bevel, and edge exclusion area of a wafer has historically been difficult to monitor for trace metals. Standard trace metal surface techniques such as total reflection x-ray fluorescence spectroscopy, time-of-flight secondary ion mass spectrometry, and vapor phase decomposition inductively coupled plasma are currently not capable or have difficulty measuring metals to the edge and bevel of the wafer. With shared metrology toolsets and new materials being introduced into semiconductor fabs, it is important to measure possible contamination in these areas of the wafer. Tools that have edge grip pins or centering and aligning pins, also are at risk to contaminate wafers at the edge and bevel. A technique had been developed known as the beveled edge analysis tool that chemically extracts contamination from the edge, bevel and edge exclusion of a wafer that is then quantified by inductively coupled plasma mass spectrometry. In this study we will show correlation of this technique to standard trace element analysis methods. We will also present data from characterizing processes and fab tools that will benefit from this measurement.

  7. A combined fiber optic digital shearography and holography system for defect inspection in Si-wafers (United States)

    Udupa, Ganesha; Wang, Jun; Ngoi, Bryan K. A.


    The present work relates to surface and/or subsurface defects inspection system for semiconductor industries and particularly to an inspection system for a defect such as swirl defects and particles in an unpolished silicon wafer before the wafer fabrication process by a combined fiber optic digital shearography and holography technique. The dual purpose camera described in this paper gives the possibility of using either digital shearography or holography (DSPI) techniques depending on application needs. The sub-surface defects in a wafer normally create strain concentrations subjected to loading (stressing) which are translated into anomalies in the fringe pattern. A real time technique with the use of Lab view Express 7 software is developed to detect defects in Si-wafer with the application of thermal oading as a stressing method. The results obtained by applying a real time fiber optic shearography technique are described in this paper. The method described here relates specifically to semiconductor wafers, but may be generalized to any other samples.

  8. Gated Silicon Drift Detector Fabricated from a Low-Cost Silicon Wafer

    Directory of Open Access Journals (Sweden)

    Hideharu Matsuura


    Full Text Available Inexpensive high-resolution silicon (Si X-ray detectors are required for on-site surveys of traces of hazardous elements in food and soil by measuring the energies and counts of X-ray fluorescence photons radially emitted from these elements. Gated silicon drift detectors (GSDDs are much cheaper to fabricate than commercial silicon drift detectors (SDDs. However, previous GSDDs were fabricated from \\(10\\-k\\(\\Omega \\cdot\\cm Si wafers, which are more expensive than \\(2\\-k\\(\\Omega \\cdot\\cm Si wafers used in commercial SDDs. To fabricate cheaper portable X-ray fluorescence instruments, we investigate GSDDs formed from \\(2\\-k\\(\\Omega \\cdot\\cm Si wafers. The thicknesses of commercial SDDs are up to \\(0.5\\ mm, which can detect photons with energies up to \\(27\\ keV, whereas we describe GSDDs that can detect photons with energies of up to \\(35\\ keV. We simulate the electric potential distributions in GSDDs with Si thicknesses of \\(0.5\\ and \\(1\\ mm at a single high reverse bias. GSDDs with one gate pattern using any resistivity Si wafer can work well for changing the reverse bias that is inversely proportional to the resistivity of the Si wafer.

  9. Gated silicon drift detector fabricated from a low-cost silicon wafer. (United States)

    Matsuura, Hideharu; Sakurai, Shungo; Oda, Yuya; Fukushima, Shinya; Ishikawa, Shohei; Takeshita, Akinobu; Hidaka, Atsuki


    Inexpensive high-resolution silicon (Si) X-ray detectors are required for on-site surveys of traces of hazardous elements in food and soil by measuring the energies and counts of X-ray fluorescence photons radially emitted from these elements. Gated silicon drift detectors (GSDDs) are much cheaper to fabricate than commercial silicon drift detectors (SDDs). However, previous GSDDs were fabricated from 10-kΩ·cm Si wafers, which are more expensive than 2-kΩ·cm Si wafers used in commercial SDDs. To fabricate cheaper portable X-ray fluorescence instruments, we investigate GSDDs formed from 2-kΩ·cm Si wafers. The thicknesses of commercial SDDs are up to 0.5 mm, which can detect photons with energies up to 27 keV, whereas we describe GSDDs that can detect photons with energies of up to 35 keV. We simulate the electric potential distributions in GSDDs with Si thicknesses of 0.5 and 1 mm at a single high reverse bias. GSDDs with one gate pattern using any resistivity Si wafer can work well for changing the reverse bias that is inversely proportional to the resistivity of the Si wafer.

  10. Wafer bonding technology for new generation vacuum MEMS: challenges and promises (United States)

    Dragoi, V.; Pabo, E.


    Various MEMS devices are incorporated into consumer electronic devices. A particular category of MEMS require vacuum packaging by wafer bonding with the need to encapsulate vacuum levels of 10-2 mbar or higher with long time stability. The vacuum requirement is limiting the choice of the wafer bonding process and raises significant challenges to the existing investigation methods (metrology) used for results qualification. From the broad range of wafer bonding processes only few are compatible with vacuum applications: fusion bonding, anodic bonding, glass frit bonding and metal-based bonding. The outgassing from the enclosed surfaces after bonding will affect the vacuum level in the cavity: in some cases, a getter material is used inside the device cavity to compensate for this outgassing. Additionally the selected bonding process must be compatible with the devices on the wafers being bonded. This work reviews the principles of vacuum encapsulation using wafer bonding. Examples showing the suitability of each process for specific applications types will be presented. A significant challenge in vacuum MEMS fabrication is the lack of analytical methods needed for process characterization or reliability testing. A short overview of the most used methods and their limitations will be presented. Specific needs to be addressed will be introduced with examples.

  11. Microwave ECR plasma electron flood for low pressure wafer charge neutralization

    Energy Technology Data Exchange (ETDEWEB)

    Vanderberg, Bo; Nakatsugawa, Tomoya; Divergilio, William [Axcelis Technologies Inc., 108 Cherry Hill Drive, Beverly, MA 01915 (United States)


    Modern ion implanters typically use dc arc discharge Plasma Electron Floods (PEFs) to neutralize wafer charge. The arc discharge requires using at least some refractory metal hardware, e.g. a thermionically emitting filament, which can be undesirable in applications where no metallic contamination is critical. rf discharge PEFs have been proposed to mitigate contamination risks but the gas flows required can result in high process chamber pressures. Axcelis has developed a microwave electron cyclotron resonance (ECR) PEF to provide refractory metals contamination-free wafer neutralization with low gas flow requirement. Our PEF uses a custom, reentrant cusp magnet field providing ECR and superior electron confinement. Stable PEF operation with extraction slits sized for 300 mm wafers can be attained at Xe gas flows lower than 0.2 sccm. Electron extraction currents can be as high as 20 mA at absorbed microwave powers < 70 W. On Axcelis' new medium current implanter, plasma generation has proven robust against pressure transients caused by, for example, photoresist outgassing by high power ion beams. Charge monitor and floating potential measurements along the wafer surface corroborate adequate wafer charge neutralization for low energy, high current ion beams.

  12. Thermal effect induced wafer deformation in high-energy e-beam lithography (United States)

    Chen, P. S.; Wang, W. C.; Lin, S. J.


    The incident surface power density in Massive Electron-beam Direct Write (MEBDW) during exposure is ~105 W/cm2, much higher than ~8 W/cm2 ArF scanners and 2.4 W/cm2 EUV. In addition, the wafer's exposure in vacuum environment makes energy dissipation even harder. This thermal effect can cause mechanical distortion of the wafer during exposure and have has a direct influence on pattern placement error and image blur. In this paper, the thermo mechanical distortions caused by wafer heating for MEB system of different electron acceleration voltages have been simulated with finite element method (FEM). The global thermal effect affected by the friction force between the wafer and the wafer chuck as well as different thermal conductivities of the chuck material are simulated. Furthermore, the thermal effects of different lithography systems such as EUV scanners and conventional optical scanners are compared. The thermal effects of MEBDW systems are shown to be acceptable.

  13. Number Determination of Successfully Packaged Dies Per Wafer Based on Machine Vision

    Directory of Open Access Journals (Sweden)

    Hsuan-Ting Chang


    Full Text Available Packaging the integrated circuit (IC chip is a necessary step in the manufacturing process of IC products. In general, wafers with the same size and process should have a fixed number of packaged dies. However, many factors decrease the number of the actually packaged dies, such as die scratching, die contamination, and die breakage, which are not considered in the existing die-counting methods. Here we propose a robust method that can automatically determine the number of actual packaged dies by using machine vision techniques. During the inspection, the image is taken from the top of the wafer, in which most dies have been removed and packaged. There are five steps in the proposed method: wafer region detection, wafer position calibration, dies region detection, detection of die sawing lines, and die number counting. The abnormal cases of fractional dies in the wafer boundary and dropped dies during the packaging are considered in the proposed method as well. The experimental results show that the precision and recall rates reach 99.83% and 99.84%, respectively, when determining the numbers of actual packaged dies in the 41 test cases.

  14. Rapid, Non-Contact Method for Measurement of Si-Wafer Thickness: Principles and Preliminary Results; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sopori, B.; Auriemma, C.; Li, C.; Madjdpour, J.


    The thickness of a semiconductor wafer can critically influence mechanical and/or electronic yield of the device(s) fabricated on it. For most microelectronic (surface) devices, the thickness of a wafer is important primarily for mechanical reasons--to provide control and stability of devices by minimizing stresses resulting from various device-fabrication processes. However, for minority-carrier devices, such as solar cells, the entire thickness of the wafer participates in the optical and electronic performance of the device. In either case, control of wafer thickness through careful measurement is a fundamental requirement in the commercial fabrication of electronic devices.

  15. Wafer-scale growth of large arrays of perovskite microplate crystals for functional electronics and optoelectronics. (United States)

    Wang, Gongming; Li, Dehui; Cheng, Hung-Chieh; Li, Yongjia; Chen, Chih-Yen; Yin, Anxiang; Zhao, Zipeng; Lin, Zhaoyang; Wu, Hao; He, Qiyuan; Ding, Mengning; Liu, Yuan; Huang, Yu; Duan, Xiangfeng


    Methylammonium lead iodide perovskite has attracted intensive interest for its diverse optoelectronic applications. However, most studies to date have been limited to bulk thin films that are difficult to implement for integrated device arrays because of their incompatibility with typical lithography processes. We report the first patterned growth of regular arrays of perovskite microplate crystals for functional electronics and optoelectronics. We show that large arrays of lead iodide microplates can be grown from an aqueous solution through a seeded growth process and can be further intercalated with methylammonium iodide to produce perovskite crystals. Structural and optical characterizations demonstrate that the resulting materials display excellent crystalline quality and optical properties. We further show that perovskite crystals can be selectively grown on prepatterned electrode arrays to create independently addressable photodetector arrays and functional field effect transistors. The ability to grow perovskite microplates and to precisely place them at specific locations offers a new material platform for the fundamental investigation of the electronic and optical properties of perovskite materials and opens a pathway for integrated electronic and optoelectronic systems.

  16. Methods for top-down fabrication of wafer scale TMDC monolayers

    Energy Technology Data Exchange (ETDEWEB)

    Das, Saptarshi; Bera, Mrinal K.; Roelofs, Andreas K; Antonio, Mark


    A method of forming a TMDC monolayer comprises providing a multi-layer transition metal dichalcogenide (TMDC) film. The multi-layer TMDC film comprises a plurality of layers of the TMDC. The multi-layer TMDC film is positioned on a conducting substrate. The conducting substrate is contacted with an electrolyte solution. A predetermined electrode potential is applied on the conducting substrate and the TMDC monolayer for a predetermined time. A portion of the plurality of layers of the TMDC included in the multi-layer TMDC film is removed by application of the predetermined electrode potential, thereby leaving a TMDC monolayer film positioned on the conducting substrate.

  17. Wafer-scale fabrication and growth dynamics of suspended graphene nanoribbon arrays

    National Research Council Canada - National Science Library

    Suzuki, Hiroo; Kaneko, Toshiro; Shibuta, Yasushi; Ohno, Munekazu; Maekawa, Yuki; Kato, Toshiaki


    Adding a mechanical degree of freedom to the electrical and optical properties of atomically thin materials can provide an excellent platform to investigate various optoelectrical physics and devices...

  18. Finely tunable laser based on a bulk silicon wafer for gas sensing applications (United States)

    Gallegos-Arellano, E.; Vargas-Rodriguez, E.; Guzman-Chavez, A. D.; Cano-Contreras, M.; Cruz, J. L.; Raja-Ibrahim, R. K.


    In this work a very simple continuously tunable laser based on an erbium ring cavity and a silicon wafer is presented. This laser can be tuned with very fine steps, which is a compulsory characteristic for gas sensing applications. Moreover the laser is free of mode hopping within a spectral range sufficiently wide to match one of the ro-vibrational lines of a target molecule. Here the proposed laser reached, at ~1530 nm, a continuous tuning range of around 950 pm (>100 GHz) before mode hopping occurred, when a silicon wafer of 355 μm thickness was used. Additionally, the laser can be finely tuned with small tuning steps of  acetylene in which the mean separation between two ro-vibrational lines is around 600 pm. Finally, it is shown that the tuning range can be modified by using wafers with different thickness.

  19. An electron-multiplying "Micromegas" grid made in silicon wafer post-processing technology

    CERN Document Server

    Chefdeville, M; Giomataris, Ioanis; van der Graaf, H; Heijne, Erik H M; Van der Putten, S; Salm, C; Schmitz, J; Smits, S; Timmermans, J; Visschers, J L


    A technology for manufacturing an aluminium grid onto a silicon wafer has been developed. The grid is fixed parallel and precisely to the wafer (anode) surface at a distance of 50 \\mum by means of insulating pillars. When some 400 V are applied between the grid and (anode) wafer, gas multiplication occurs : primary electrons from the drift space above the grid enter the holes and cause electron avalanches in the high-field region between the grid and the anode. Production and operational characteristics of the device are described. With this newly developed technology, CMOS (pixel) readout chips can be covered with a gas multiplication grid. Such a chip forms, together with the grid, an integrated device which can be applied as readout in a wide field of gaseous detectors.

  20. Feature profile evolution in plasma processing using on-wafer monitoring system

    CERN Document Server

    Samukawa, Seiji


    This book provides for the first time a good understanding of the etching profile technologies that do not disturb the plasma. Three types of sensors are introduced: on-wafer UV sensors, on-wafer charge-up sensors and on-wafer sheath-shape sensors in the plasma processing and prediction system of real etching profiles based on monitoring data. Readers are made familiar with these sensors, which can measure real plasma process surface conditions such as defect generations due to UV-irradiation, ion flight direction due to charge-up voltage in high-aspect ratio structures and ion sheath conditions at the plasma/surface interface. The plasma etching profile realistically predicted by a computer simulation based on output data from these sensors is described.

  1. Efficiency Improvement of HIT Solar Cells on p-Type Si Wafers

    Directory of Open Access Journals (Sweden)

    Chun-You Wei


    Full Text Available Single crystal silicon solar cells are still predominant in the market due to the abundance of silicon on earth and their acceptable efficiency. Different solar-cell structures of single crystalline Si have been investigated to boost efficiency; the heterojunction with intrinsic thin layer (HIT structure is currently the leading technology. The record efficiency values of state-of-the art HIT solar cells have always been based on n-type single-crystalline Si wafers. Improving the efficiency of cells based on p-type single-crystalline Si wafers could provide broader options for the development of HIT solar cells. In this study, we varied the thickness of intrinsic hydrogenated amorphous Si layer to improve the efficiency of HIT solar cells on p-type Si wafers.

  2. Three-Stage Tracking Control for the LED Wafer Transporting Robot

    Directory of Open Access Journals (Sweden)

    Zuoxun Wang


    Full Text Available In order to ensure the steady ability of the LED wafer transporting robot, a high order polynomial interpolation method is proposed to plan the motion process of the LED wafer transporting robot. According to the LED wafer transporting robot which is fast and has no vibration, fifth-order polynomial is applied to complete the robot’s motion planning. A new subsection search method is proposed to optimize the transporting robot’s acceleration. Optimal planning curve is achieved by the subsection searching. Extended Kalman filter algorithm and PID algorithm are employed to follow the tracks of planned path. MATLAB simulation and experiment confirm the validity and efficiency of the proposed method.

  3. Aerial image measurement technique for automated reticle defect disposition (ARDD) in wafer fabs (United States)

    Zibold, Axel M.; Schmid, Rainer M.; Stegemann, B.; Scheruebl, Thomas; Harnisch, Wolfgang; Kobiyama, Yuji


    The Aerial Image Measurement System (AIMS)* for 193 nm lithography emulation has been brought into operation successfully worldwide. A second generation system comprising 193 nm AIMS capability, mini-environment and SMIF, the AIMS fab 193 plus is currently introduced into the market. By adjustment of numerical aperture (NA), illumination type and partial illumination coherence to match the conditions in 193 nm steppers or scanners, it can emulate the exposure tool for any type of reticles like binary, OPC and PSM down to the 65 nm node. The system allows a rapid prediction of wafer printability of defects or defect repairs, and critical features, like dense patterns or contacts on the masks without the need to perform expensive image qualification consisting of test wafer exposures followed by SEM measurements. Therefore, AIMS is a mask quality verification standard for high-end photo masks and established in mask shops worldwide. The progress on the AIMS technology described in this paper will highlight that besides mask shops there will be a very beneficial use of the AIMS in the wafer fab and we propose an Automated Reticle Defect Disposition (ARDD) process. With smaller nodes, where design rules are 65 nm or less, it is expected that smaller defects on reticles will occur in increasing numbers in the wafer fab. These smaller mask defects will matter more and more and become a serious yield limiting factor. With increasing mask prices and increasing number of defects and severability on reticles it will become cost beneficial to perform defect disposition on the reticles in wafer production. Currently ongoing studies demonstrate AIMS benefits for wafer fab applications. An outlook will be given for extension of 193 nm aerial imaging down to the 45 nm node based on emulation of immersion scanners.

  4. Lateral cavity photonic crystal surface emitting laser based on commercial epitaxial wafer. (United States)

    Wang, Yufei; Qu, Hongwei; Zhou, Wenjun; Qi, Aiyi; Zhang, Jianxin; Liu, Lei; Zheng, Wanhua


    A lateral cavity photonic crystal surface emitting laser (LC-PCSEL) with airholes of cone-like shape etched near to the active layer is fabricated. It employs only a simple commercial epitaxial wafer without DBR and needs no wafer bonding technique. Surface emitting lasing action at 1575 nm with power of 1.8 mW is observed at room temperature, providing potential values for mass production of electrically driven PCSELs with low cost. Additionally, Fano resonance is utilized to analyze aperture equivalence of PC, and energy distribution in simplified laser structure is simulated to show oscillation and transmission characteristics of laser.

  5. An electrochemical cell for the efficient turn around of wafer working electrodes. (United States)

    Wozniak, Nicholas R; Frey, Alyssa A; Osterbur, Lucas W; Boman, Timothy S; Hampton, Jennifer R


    We present a new design for an electrochemical cell for use with wafer working electrodes. The key feature of the design is the use of half turn thumb screws to form a liquid-tight seal between an o-ring and the sample surface. The assembly or disassembly of the cell requires a half turn of each thumb screw, which facilitates the quick turn around of wafer samples. The electrochemical performance of the cell is demonstrated by cyclic voltammetry and double step chronoamperometry measurements of the ferricyanide/ferrocyanide couple.

  6. Probing and irradiation tests of ALICE pixel chip wafers and sensors

    CERN Document Server

    Cinausero, M; Antinori, F; Chochula, P; Dinapoli, R; Dima, R; Fabris, D; Galet, G; Lunardon, M; Manea, C; Marchini, S; Martini, S; Moretto, S; Pepato, Adriano; Prete, G; Riedler, P; Scarlassara, F; Segato, G F; Soramel, F; Stefanini, G; Turrisi, R; Vannucci, L; Viesti, G


    In the framework of the ALICE Silicon Pixel Detector (SPD) project a system dedicated to the tests of the ALICE1LHCb chip wafers has been assembled and is now in use for the selection of pixel chips to be bump-bonded to sensor ladders. In parallel, radiation hardness tests of the SPD silicon sensors have been carried out using the 27 MeV proton beam delivered by the XTU TANDEM accelerator at the SIRAD facility in LNL. In this paper we describe the wafer probing and irradiation set-ups and we report the obtained results. (6 refs).

  7. Bismuth onion thin film in situ grown on silicon wafer synthesized through a hydrothermal approach (United States)

    Zhao, Yue; Liu, Hong; Liu, Jin; Hu, Chenguo; Wang, Jiyang


    Bismuth onion structured nanospheres with the same structure as carbon onions have been synthesized and observed. The nanospheres were synthesized through a hydrothermal method using bismuth hydroxide and silicon wafer as reactants. By controlling the heating temperature, heating time, and the pressure, nanoscale bismuth spheres can be in situ synthesized on silicon wafer, and forms a bismuth onion film on the substrate. The electronic property of the films was investigated. A formation mechanism of the formation of bismuth onions and the onion film has been proposed on the basis of experimental observations.

  8. Micropore x-ray optics using anisotropic wet etching of (110) silicon wafers. (United States)

    Ezoe, Yuichiro; Koshiishi, Masaki; Mita, Makoto; Mitsuda, Kazuhisa; Hoshino, Akio; Ishisaki, Yoshitaka; Yang, Zhen; Takano, Takayuki; Maeda, Ryutaro


    To develop x-ray mirrors for micropore optics, smooth silicon (111) sidewalls obtained after anisotropic wet etching of a silicon (110) wafer were studied. A sample device with 19 microm wide (111) sidewalls was fabricated using a 220 microm thick silicon (110) wafer and potassium hydroxide solution. For what we believe to be the first time, x-ray reflection on the (111) sidewalls was detected in the angular response measurement. Compared to ray-tracing simulations, the surface roughness of the sidewalls was estimated to be 3-5 nm, which is consistent with the atomic force microscope and the surface profiler measurements.

  9. Split-Capacitance and Conductance-Frequency Characteristics of SOI Wafers in Pseudo-MOSFET Configuration

    KAUST Repository

    Pirro, Luca


    Recent experimental results have demonstrated the possibility of characterizing silicon-on-insulator (SOI) wafers through split C-V measurements in the pseudo-MOSFET configuration. This paper analyzes the capacitance and conductance versus frequency characteristics. We discuss the conditions under which it is possible to extract interface trap density in bare SOI wafers. The results indicate, through both measurements and simulations, that the signature due to interface trap density is present in small-area samples, but is masked by the RC response of the channel in regular, large-area ones, making the extraction in standard samples problematic. © 1963-2012 IEEE.

  10. An electrochemical cell for the efficient turn around of wafer working electrodes (United States)

    Wozniak, Nicholas R.; Frey, Alyssa A.; Osterbur, Lucas W.; Boman, Timothy S.; Hampton, Jennifer R.


    We present a new design for an electrochemical cell for use with wafer working electrodes. The key feature of the design is the use of half turn thumb screws to form a liquid-tight seal between an o-ring and the sample surface. The assembly or disassembly of the cell requires a half turn of each thumb screw, which facilitates the quick turn around of wafer samples. The electrochemical performance of the cell is demonstrated by cyclic voltammetry and double step chronoamperometry measurements of the ferricyanide/ferrocyanide couple.

  11. First thin AC-coupled silicon strip sensors on 8-inch wafers

    Energy Technology Data Exchange (ETDEWEB)

    Bergauer, T., E-mail: [Institute of High Energy Physics of the Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Wien (Vienna) (Austria); Dragicevic, M.; König, A. [Institute of High Energy Physics of the Austrian Academy of Sciences, Nikolsdorfer Gasse 18, 1050 Wien (Vienna) (Austria); Hacker, J.; Bartl, U. [Infineon Technologies Austria AG, Siemensstrasse 2, 9500 Villach (Austria)


    The Institute of High Energy Physics (HEPHY) in Vienna and the semiconductor manufacturer Infineon Technologies Austria AG developed a production process for planar AC-coupled silicon strip sensors manufactured on 200 μm thick 8-inch p-type wafers. In late 2015, the first wafers were delivered featuring the world's largest AC-coupled silicon strip sensors. Detailed electrical measurements were carried out at HEPHY, where single strip and global parameters were measured. Mechanical studies were conducted and the long-term behavior was investigated using a climate chamber. Furthermore, the electrical properties of various test structures were investigated to validate the quality of the manufacturing process.

  12. Thermal and structural assessments of a ceramic wafer seal in hypersonic engines (United States)

    Tong, Mike T.; Steinetz, Bruce M.


    The thermal and structural performances of a ceramic wafer seal in a simulated hypersonic engine environment are numerically assessed. The effects of aerodynamic heating, surface contact conductance between the seal and its adjacent surfaces, flow of purge coolant gases, and leakage of hot engine flow path gases on the seal temperature were investigated from the engine inlet back to the entrance region of the combustion chamber. Finite element structural analyses, coupled with Weibull failure analyses, were performed to determine the structural reliability of the wafer seal.

  13. Thermal and structural assessments of a ceramic wafer seal in hypersonic engine (United States)

    Tong, Mike; Steinetz, Bruce


    The thermal and structural performances of a ceramic wafer seal in a simulated hypersonic engine environment are numerically assessed. The effects of aerodynamic heating, surface contact conductance between the seal and its adjacent surfaces, flow of purge coolant gases, and leakage of hot engine flow path gases on the seal temperature were investigated from the engine inlet back to the entrance region of the combustion chamber. Finite element structural analyses, coupled with Weibull failure analyses, were performed to determine the structural reliability of the wafer seal.

  14. A Substrate-Reclamation Technology for GaN-Based Lighting-Emitting Diodes Wafer

    Directory of Open Access Journals (Sweden)

    Shih-Yung Huang


    Full Text Available This study reports on the use of a substrate-reclamation technology for a gallium nitride (GaN-based lighting-emitting diode (LED wafer. There are many ways to reclaim sapphire substrates of scrap LED wafers. Compared with a common substrate-reclamation method based on chemical mechanical polishing, this research technology exhibits simple process procedures, without impairing the surface morphology and thickness of the sapphire substrate, as well as the capability of an almost unlimited reclamation cycle. The optical performances of LEDs on non-reclaimed and reclaimed substrates were consistent for 28.37 and 27.69 mcd, respectively.

  15. Prevalencia de lesiones en gimnastas pertenecientes a la Liga de Gimnasia de Bogotá, D.C.

    Directory of Open Access Journals (Sweden)

    Diego Fabricio Rodríguez-Camacho


    Full Text Available Introducción. La exigencia física en los gimnastas durante su formación puede traer consigo lesiones; la intensidad y cantidad de práctica en relación al nivel de competencia y grado de dificultad de los elementos hacen de este deporte uno de los que mayores lesiones produce. Objetivo. Estimar la prevalencia de lesiones y los factores correlacionados a estas en gimnastas pertenecientes a la Liga de Gimnasia de Bogotá, Colombia. Materiales y métodos. Estudio observacional, correlacional y con diseño transversal realizado en 19 gimnastas: nueve mayores de 14 años, nueve entre 15 y 19 y uno de 22 años. Se midió índice de masa corporal (IMC, peso corporal, talla, squat jump, contra movimiento, pliometría en miembros superiores, dinamometría de espalda y sit and reach; también se realizó una encuesta de prevalencia de lesiones. Resultados. 14 deportistas presentaron lesiones el último año. El lugar de lesión más prevalente fue codo con 24%, seguido de pie con 21%. El tipo de lesión más prevalente fue esguince con 31.6%, seguido por tendinopatía con 21%. No hubo correlación entre squat jump, contra movimiento, pliometría en miembros superiores, dinamometría de espalda y sit and reach. Conclusiones. Las variables edad, peso, IMC y duración del entrenamiento se correlacionan con la aparición de lesiones. Las mujeres sufren más lesiones en comparación con hombres.

  16. Welding shape memory alloys with NdYAG lasers Soldadura de ligas de memória de forma com laser Nd-YAG

    Directory of Open Access Journals (Sweden)

    Luisa Quintino


    Full Text Available The demand of emerging joining techniques for shape memory alloys (SMA has become of great importance, as their functional properties namely shape memory effect (SME and superelasticity (SE present unique solutions for state-of-the-art applications. Welding of SMAs is a challenge due to the risk of reduced mechanical performance after laser processing. The wider application of these alloys in various sectors as aerospace, medical or electronic industry is hindered by the limitations in its processing. The need to weld SMAs to other materials is pressing for applications in the above referred sectors. In dissimilar joints the need to understand materials behavior is even more challenging since base materials have different physical properties leading to different heat flow, convection processes and residual stress distribution. The chemical composition across the weld pool varies and intermetallic compounds are formed. Research detailing the effects of laser processing on NiTi is essential to overcome many of these challenges. The objectives of the current study are to analyze the effects of laser welding in the weld shape of both similar and dissimilar joints of NiTi to stainless steel and titanium alloys.A procura de técnicas de ligação para ligas de memória de forma tem-se revetido de importância crescente, devido ao desenvolvimento de aplicações deste material com particulares propriedades de memória de forma e superelasticidade. A soldadura de ligas de memória de forma é um desafio devido ao risco de emporbrecimento das propriedades mecânicas depois do processamento laser. A aplicação alargarda destas ligas em vários sectores como o aeroespacial, medico ou electrónico é prejudicado pelas limitações de processamento. A necessidade de soldar ligas de memória de forma a outros materiais é premente para estes sectores. Em juntas dissimilares, o entendimento do comportamento dos materaias é um desafio ainda maior uma vez que

  17. New Technique to Determine Gettering Efficiency of Heavy Metals and Its Application to Carbon-Ion-Implanted Si Epitaxial Wafers (United States)

    Itoga, Toshihiko; Hozawa, Kazuyuki; Takeda, Kazuo; Isomae, Seiichi; Ohkura, Makoto


    Using a newly developed method to evaluate the gettering efficiency of Si wafers, we found that C-ion implantation prior to epitaxial growth greatly improves the gettering efficiency of heavy metals in epitaxial Si wafers. The gettering efficiency was evaluated through direct observation by total X-ray reflection fluorescence (TXRF) by counting the number of heavy metal atoms that diffused from the back to the front surface of wafers. Heavy metals were deposited on the backside surface of Si wafers from metal-dissolved aqua solution. Two-step annealing was carried out after the deposition. The first step caused metal diffusion and the second produced precipitation from the front surface of the wafers. The effectiveness of the method was confirmed by comparing the results obtained from as-received and intrinsic (or internal) gettering (IG)-processed Czochralski-grown Si wafers. The method was applied to C-ion-implanted epitaxial Si wafers to confirm the improvement in gettering efficiency in accordance with the implanted C dose. The effectiveness of the C-ion implantation was also confirmed by evaluating the electrical characteristics of the oxide grown on the Si wafers.

  18. Ensaio do anel para avaliação do comportamento do coeficiente de atrito da liga de alumínio AA6351


    Bueno, Alex Fabiano; Martins, Vinicius; Rodrigues, Wilson Correa; Petter, Alex Willian; Pfingstag, Maiquel Emerson; Schaeffer, Lirio


    O objetivo deste trabalho é realizar um estudo comparativo sobre a influência de lubrificantes no coeficiente de atrito da liga de alumínio AA6351. O atrito tem um efeito significativo na deformação do material, alterando a força de compressão e o desgaste da matriz e da peça. A escolha de um lubrificante com eficiência na redução do atrito da interface peça/matriz aumenta à vida útil da ferramenta e, consequentemente, melhora a margem de lucro quando em produção industrial. Para o forjamento...

  19. Microestrutura e propriedades de revestimentos de liga CoCrMoSi (Tribaloy T400) obtidos por plasma com arco transferido


    Bohatch, Rafael Guetter


    Orientador : Prof. Dr. Adriano Scheid Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Mecânica. Defesa: Curitiba, 12/12/2014 Inclui referências Resumo: Ligas de Cobalto CoCrMoSi são largamente usadas para a proteção de componentes que operam em condições agressivas de desgaste, corrosão em diversos meios e elevadas temperaturas. Desempenho promissor tem sido relatado para o processamento de revestimentos pela técni...

  20. Los convenios internacionales de lucha contra el terrorismo de la Liga Arabe y de la Organización de la Conferencia Islámica


    Botta, Jorge Paulo


    Este trabajo, de caracter eminentemente descriptivo, veremos cuales son las líneas básicas de la política antiterrorista consensuada por los estados miembros de la Liga de los Estados Arabes y los de la Organización de la Conferencia Islámica según se puede inferir de los acuerdos en sobre esta material generados en estas organizaciones. Estos instrumentos internacionales son: el Acuerdo Arabe para la Lucha contra el Terrorismo (El Cairo, abril de 1998) y la Declaración Final de la Confere...

  1. Novel variable-temperature chuck for use in the detection of deep levels in processed semiconductor wafers. (United States)

    Koyama, R Y; Buehler, M G


    This paper describes the design, construction, and characterization of a variable-temperature wafer apparatus for use in the detection of electrically active defects which produce deep levels in the band gap of silicon. In its present form, the wafer chuck can heat and cool wafers as large as 51 mm in diameter over the temperature range from -196 degrees to 350 degrees C. Heating rates as high as 7 degrees C/s have been achieved. Sensitivity for electrical measurements is sufficient to allow current measurements as low as 0.2 pA or capacitance changes (1 MHz) as small as 5 fF. The use of this apparatus is illustrated by wafer mapping the gold defect density in diodes fabricated across a silicon wafer.

  2. Switchable static friction of piezoelectric composite—silicon wafer contacts

    NARCIS (Netherlands)

    Van den Ende, D.A.; Fischer, H.R.; Groen, W.A.; Van der Zwaag, S.


    The meso-scale surface roughness of piezoelectric fiber composites can be manipulated by applying an electric field to a piezocomposite with a polished surface. In the absence of an applied voltage, the tips of the embedded piezoelectric ceramic fibers are below the surface of the piezocomposite and

  3. Controllable elastocapillary folding of silicon nitride 3D structures by through-wafer filling

    NARCIS (Netherlands)

    Legrain, A.B.H.; Janson, T.G.; Berenschot, Johan W.; Krijnen, Gijsbertus J.M.; Abelmann, Leon; Tas, Niels Roelof


    We present the controllable capillary folding of planar silicon nitride templates into 3D micro-structures by means of through-wafer liquid application. We demonstrate for the first time hydro-mechanical, repeatable, actuation of capillary folded structures via addition or retraction of water on

  4. Fluorescent 'two-faced' polymer wafers with embedded pyrene-functionalised gelator nanofibres. (United States)

    Moffat, Jamie R; Smith, David K


    Pyrene-functionalised gelators self-assemble into nano-fibrillar organogels in DMSO/styrene/divinylbenzene mixtures, which when polymerised yield polymer wafers with two distinct faces, only one of which is fluorescent and has embedded gelator nanofibres. This journal is © The Royal Society of Chemistry 2011

  5. 75 FR 76952 - Grant of Authority for Subzone Status; Lam Research Corporation (Wafer Fabrication Equipment... (United States)


    ... Foreign-Trade Zones Board Grant of Authority for Subzone Status; Lam Research Corporation (Wafer... distribution facilities of Lam Research Corporation, located in Fremont, Newark, and Livermore, California... equipment at the facilities of Lam Research Corporation, located in Fremont, Newark, and Livermore...

  6. Nanomanipulation of 2 inch wafer fabrication of vertically aligned carbon nanotube arrays by nanoimprint lithography

    DEFF Research Database (Denmark)

    Bu, Ian Y. Y.; Eichhorn, Volkmar; Carlson, Kenneth


    pattern transfer to a hard metal mask before deep reactive ion etching (RIE) to form the stamp protrusions. This stamp master is then pressed against a wafer covered with nanoimprint resist, at a temperature above the glass transition temperature, transferring the pattern to polymer. Using this process...

  7. Low temperature fusion wafer bonding quality investigation for failure mode analysis

    NARCIS (Netherlands)

    Dragoi, V.; Czurratis, P.; Brand, S.; Beyersdorfer, J.; Patzig, C.; Krugers, J.P.; Schrank, F.; Siegert, J.; Petzold, M.


    In this paper, a brief summary of potential defect formation and failure characteristics for low temperature plasma-assisted Si wafer bonding in correlation to different influencing factors is given. In terms of a failure catalogue classification, these defects are related to incoming material

  8. Graphene-Decorated Nanocomposites for Printable Electrodes in Thin Wafer Devices (United States)

    Bakhshizadeh, N.; Sivoththaman, S.


    Printable electrodes that induce less stress and require lower curing temperatures compared to traditional screen-printed metal pastes are needed in thin wafer devices such as future solar cells, and in flexible electronics. The synthesis of nanocomposites by incorporating graphene nanopowders as well as silver nanowires into epoxy-based electrically conductive adhesives (ECA) is examined to improve electrical conductivity and to develop alternate printable electrode materials that induce less stress on the wafer. For the synthesized graphene and Ag nanowire-decorated ECA nanocomposites, the curing kinetics were studied by dynamic and isothermal differential scanning calorimetry measurements. Thermogravimetric analysis on ECA, ECA-AG and ECA/graphene nanopowder nanocomposites showed that the temperatures for onset of decomposition are higher than their corresponding glass transition temperature (T g) indicating an excellent thermal resistance. Printed ECA/Ag nanowire nanocomposites showed 90% higher electrical conductivity than ECA films, whereas the ECA/graphene nanocomposites increased the conductivity by over two orders of magnitude. Scanning electron microscopy results also revealed the effect of fillers morphology on the conductivity improvement and current transfer mechanisms in nanocomposites. Residual stress analysis performed on Si wafers showed that the ECA and nanocomposite printed wafers are subjected to much lower stress compared to those printed with metallic pastes. The observed parameters of low curing temperature, good thermal resistance, reasonably high conductivity, and low residual stress in the ECA/graphene nanocomposite makes this material a promising alternative in screen-printed electrode formation in thin substrates.

  9. Design Expert Supported Mathematical Optimization and Predictability Study of Buccoadhesive Pharmaceutical Wafers of Loratadine (United States)

    Dey, Surajit; Parcha, Versha; Bhattacharya, Shiv Sankar; Ghosh, Amitava


    Objective. The objective of this work encompasses the application of the response surface approach in the development of buccoadhesive pharmaceutical wafers of Loratadine (LOR). Methods. Experiments were performed according to a 32 factorial design to evaluate the effects of buccoadhesive polymer, sodium alginate (A), and lactose monohydrate as ingredient, of hydrophilic matrix former (B) on the bioadhesive force, disintegration time, percent (%) swelling index, and time taken for 70% drug release (t 70%). The effect of the two independent variables on the response variables was studied by response surface plots and contour plots generated by the Design-Expert software. The desirability function was used to optimize the response variables. Results. The compatibility between LOR and the wafer excipients was confirmed by differential scanning calorimetry, FTIR spectroscopy, and X-ray diffraction (XRD) analysis. Bioadhesion force, measured with TAXT2i texture analyzer, showed that the wafers had a good bioadhesive property which could be advantageous for retaining the drug into the buccal cavity. Conclusion. The observed responses taken were in agreement with the experimental values, and Loratadine wafers were produced with less experimental trials, and a patient compliant product was achieved with the concept of formulation by design. PMID:23781498

  10. Study of ammonium fluoride passivation time on CdZnTe bulk crystal wafers

    Energy Technology Data Exchange (ETDEWEB)

    Bensalah, H.; Crocco, J.; Carcelen, V.; Plaza, J.L.; Zheng, Q.; Dieguez, E. [Crystal Growth Laboratory, Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain); Marchini, L. [IMEM-CNR, Parma (Italy); Zanichelli, M. [Department of Physics, University of Parma (Italy); Dominguez, G.; Soriano, L. [Departamento de Fisica Aplicada and Instituto de Ciencias de Materiales Nicolas Cabrera, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)


    The chemical etching and the passivation processes of CdZnTe wafers were studied. The treatment effects were tested through an X-Ray Photoelectron Spectroscopy (XPS) analysis and I-V measurement. The chemical etching in 2%Br-MeOH solution may effectively remove the damaged layer and improve the ohmic contact between CdZnTe wafer and Au electrodes making rich the surface with Te. After different etching times, the CdZnTe wafers were passivated with NH{sub 4}F/H{sub 2}O{sub 2}.CdZnTe wafer passivated immediately after etching showed the best passivation efficiency because the enriched Te on the surface was fully oxidized to TeO{sub 2}, which results in the thickest oxide layer, and the most stoichiometric surface. Also the surface leakage current was reduced in comparison with the sample passivated 24 h after etching. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  11. Graphene-Decorated Nanocomposites for Printable Electrodes in Thin Wafer Devices (United States)

    Bakhshizadeh, N.; Sivoththaman, S.


    Printable electrodes that induce less stress and require lower curing temperatures compared to traditional screen-printed metal pastes are needed in thin wafer devices such as future solar cells, and in flexible electronics. The synthesis of nanocomposites by incorporating graphene nanopowders as well as silver nanowires into epoxy-based electrically conductive adhesives (ECA) is examined to improve electrical conductivity and to develop alternate printable electrode materials that induce less stress on the wafer. For the synthesized graphene and Ag nanowire-decorated ECA nanocomposites, the curing kinetics were studied by dynamic and isothermal differential scanning calorimetry measurements. Thermogravimetric analysis on ECA, ECA-AG and ECA/graphene nanopowder nanocomposites showed that the temperatures for onset of decomposition are higher than their corresponding glass transition temperature ( T g) indicating an excellent thermal resistance. Printed ECA/Ag nanowire nanocomposites showed 90% higher electrical conductivity than ECA films, whereas the ECA/graphene nanocomposites increased the conductivity by over two orders of magnitude. Scanning electron microscopy results also revealed the effect of fillers morphology on the conductivity improvement and current transfer mechanisms in nanocomposites. Residual stress analysis performed on Si wafers showed that the ECA and nanocomposite printed wafers are subjected to much lower stress compared to those printed with metallic pastes. The observed parameters of low curing temperature, good thermal resistance, reasonably high conductivity, and low residual stress in the ECA/graphene nanocomposite makes this material a promising alternative in screen-printed electrode formation in thin substrates.

  12. Smart mask ship to control for enhanced on wafer CD performance (United States)

    Utzny, Clemens; Schumacher, Karl; Seltmann, Rolf


    In the process of semicondutcor fabrication the translation of the final product requirements into specific targets for each component of the manufacturing process is one of the most demanding tasks. This involves the careful assessment of the error budgets of each component as well as the sensible balancing of the costs implied by the requirements. Photolithographic masks play a pivotal role in the semiconductor fabrication. This attributes a crucial role to mask error budgeting within the overall wafer production process. Masks with borderline performance with respect to the wafer fabrication requirements have a detrimental effect on the wafer process window thus inducing delays and costs. However, prohibitively strict mask specifications will induce large costs and delays in the mask manufacturing process. Thus setting smart control mechanisms for mask quality assessment is highly relevant for an efficient production flow. To this end GLOBALFOUNDRIES and the AMTC have set up a new mask specification check to enable a smart ship to control process for mask manufacturing. Within this process the mask CD distribution is checked as to whether it is commensurable with the advanced dose control capabilities of the stepper in the wafer factory. If this is the case, masks with borderline CD performance will be usable within the manufacturing process as the signatures can be compensated. In this paper we give a detailed explanation of the smart ship control approach with its implications for mask quality.

  13. A facility for plastic deformation of germanium single-crystal wafers

    DEFF Research Database (Denmark)

    Lebech, B.; Theodor, K.; Breiting, B.


    . All movements and temperature changes are done by a robot via a PLC-control system. Two nine-crystal focusing monochromators (54 x 116 and 70 x 116 mm(2)) made from 100 wafers with average mosaicity similar to 13' have been constructed. Summaries of the test results are presented. (C) 1998 Elsevier...

  14. Residual stress in silicon caused by Cu-Sn wafer-level packaging

    NARCIS (Netherlands)

    Taklo, M.M.V.; Vardøy, A.S.; Wolf, I. de; Simons, V.; Wiel, H.J. van de; Waal, A. van der; Lapadatu, A.; Martinsen, S.; Wunderle, B.


    The level of stress in silicon as a result of applying Cu-Sn SLID wafer level bonding to hermetically encapsulate a highperformance infrared bolometer device was studied. Transistors are present in the read out integrated circuit (ROIC) of the device and some are located below the bond frame. Test

  15. Low temperature sacrificial wafer bonding for planarization after very deep etching

    NARCIS (Netherlands)

    Spiering, V.L.; Spiering, V.L.; Berenschot, Johan W.; Elwenspoek, Michael Curt; Fluitman, J.H.J.


    A new technique, at temperatures of 150°C or 450°C, that provides planarization after a very deep etching step in silicon is presented. Resist spinning and layer patterning as well as realization of bridges or cantilevers across deep holes becomes possible. The sacrificial wafer bonding technique

  16. Fabrication of through-wafer 3D microfluidics in silicon carbide using femtosecond laser (United States)

    Huang, Yinggang; Wu, Xiudong; Liu, Hewei; Jiang, Hongrui


    We demonstrate a prototype through-wafer microfluidic structure in bulk silicon carbide (SiC) fabricated by femtosecond laser micromachining. The effects of laser fluence and scanning speed on the laser-affected zone are also investigated. Furthermore, the wettability of the laser-affected surface for the target liquid, mineral oil, is examined. Microchannels of various cross-sectional shapes are fabricated by the femtosecond laser and their effects on the liquid flow are simulated and compared. This fabrication approach offers a fast and efficient route to implement SiC-based through-wafer micro-structures, which are not able to be realized using other methods such as chemical etching. The flexibility of manufacturing 3D structures based on this fabrication method enables more complex structures as well. Smooth liquid flow in the microchannels of the bulk SiC substrate is presented. The work shown here paves a new way for various applications such as reliable microfluidic systems in a high-temperature, high radioactivity, and corrosive environment, and could be combined with SiC wafer-to-wafer bonding to realize a plethora of novel microelectromechanical (MEMS) structures.

  17. Output blue light evaluation for phosphor based smart white LED wafer level packages

    NARCIS (Netherlands)

    Kolahdouz Esfahani, Z.; Rostamian, Ali; Kolahdouz, Mohammadreza; Ma, Teng; van Zeijl, H.W.; Zhang, G.Q.


    This study presents a blue light detector for evaluating the output light of phosphor based white LED package. It is composed of a silicon stripe-shaped photodiode designed and implemented in a 2 μm BiCMOS process which can be used for wafer level integration of different passive and active devices

  18. Resistência ao cisalhamento entre ligas metálicas e materiais compostos para revestimento estético: cerômero e polímero de vidro


    Itinoche, Marcos Koiti; Kimpara, Estevão Tomomitsu [UNESP; Bottino, Marco Antonio; Neisser, Maximiliano Piero; Oyafuso, Denise Kanashiro


    O propósito deste trabalho foi avaliar a resistência ao cisalhamento entre ligas metálicas (Au, NiCr e CoCr) e materiais estéticos indiretos (Artglass e Targis). Para tanto, utilizaram-se vinte estruturas metálicas de cada tipo de liga, cuja superfície a ser aplicada os materiais estéticos, receberam jateamento com óxido de alumínio de granulação de 250mm, antes da aplicação do sistema adesivo do corresp...

  19. Vertical integration of array-type miniature interferometers at wafer level by using multistack anodic bonding (United States)

    Wang, Wei-Shan; Wiemer, Maik; Froemel, Joerg; Enderlein, Tom; Gessner, Thomas; Lullin, Justine; Bargiel, Sylwester; Passilly, Nicolas; Albero, Jorge; Gorecki, Christophe


    In this work, vertical integration of miniaturized array-type Mirau interferometers at wafer level by using multi-stack anodic bonding is presented. Mirau interferometer is suitable for MEMS metrology and for medical imaging according to its vertical-, lateral- resolutions and working distances. Miniaturized Mirau interferometer can be a promising candidate as a key component of an optical coherence tomography (OCT) system. The miniaturized array-type interferometer consists of a microlens doublet, a Si-based MEMS Z scanner, a spacer for focus-adjustment and a beam splitter. Therefore, bonding technologies which are suitable for heterogeneous substrates are of high interest and necessary for the integration of MEMS/MOEMS devices. Multi-stack anodic bonding, which meets the optical and mechanical requirements of the MOEMS device, is adopted to integrate the array-type interferometers. First, the spacer and the beam splitter are bonded, followed by bonding of the MEMS Z scanner. In the meanwhile, two microlenses, which are composed of Si and glass wafers, are anodically bonded to form a microlens doublet. Then, the microlens doublet is aligned and bonded with the scanner/spacer/beam splitter stack. The bonded array-type interferometer is a 7- wafer stack and the thickness is approximately 5mm. To separate such a thick wafer stack with various substrates, 2-step laser cutting is used to dice the bonded stack into Mirau chips. To simplify fabrication process of each component, electrical connections are created at the last step by mounting a Mirau chip onto a flip chip PCB instead of through wafer vias. Stability of Au/Ti films on the MEMS Z scanner after anodic bonding, laser cutting and flip chip bonding are discussed as well.

  20. Characterization study of an aqueous developable photosensitive polyimide on 300-mm wafers (United States)

    Flack, Warren W.; Kulas, Scott; Franklin, Craig L.


    The advent of 300 mm wafer processing for semiconductor manufacturing has had a great impact on the development of photolithographic materials, equipment and associated processes. At the same time advanced packaging techniques for these semiconductor devices are making strides for smaller, faster and lower cost parts with improved reliability. Photosensitive polyimides are used for passivation stress buffer relief and soft error protection on almost all memory devices such as DRAM as well as final passivation layers for subsequent interconnect bumping operations on most of today's advanced microprocessors. For processing simplicity and total cost of ownership, it is desirable to use an aqueous developable polyimide to maintain compatibility with standard photoresist processes. This study will investigate the feasibility of processing photosensitive polyimides on 300 mm wafers. The performance of a commercially available, positive acting, aqueous developable polyimide is examined at a thickness appropriate for logic devices. A broadband stepper is utilized since polyimides are highly aromatic polymers that strongly absorb UV light below 350 nm. This stepper exposes photosensitive films using mercury vapor spectrum output from 390 nm to 450 nm (g and h-line) and allows rapid exposure of both broadband as well as narrow spectral sensitive films. The system has been optimized for thick photoresists and polyimides and uses a combination of low numerical aperture with maximum wafer level intensity to achieve well formed images in thick films. Process capability for 300 mm wafers is determined by analyzing polyimide film thickness uniformity and critical dimension (CD) control across the wafer. Basic photoresist characterization techniques such as cross sectional SEM analysis, process linearity and process windows are also used to establish lithographic capabilities. The trade-offs for various process capability windows are reviewed to determine the optimum process

  1. Safety and efficacy of Gliadel wafers for newly diagnosed and recurrent glioblastoma. (United States)

    De Bonis, Pasquale; Anile, Carmelo; Pompucci, Angelo; Fiorentino, Alba; Balducci, Mario; Chiesa, Silvia; Maira, Giulio; Mangiola, Annunziato


    Combining Gliadel wafers and radiochemotherapy with TMZ may carry the risk of increased adverse events (AE). We analyzed the efficacy and safety in patients with glioblastoma who underwent multimodal treatment with implantation of Gliadel wafers. One hundred sixty-five consecutive patients with newly diagnosed (77 patients) or recurrent (88 patients) glioblastoma were studied. Forty-seven patients underwent surgery + Gliadel. The impact of age (≥65 vs. <65), resection extent (gross total vs. partial), use of Gliadel and adjuvant treatment (TMZ vs. other schemes/no adjuvant therapy) on overall survival (OS, for patients with newly diagnosed glioblastoma) and on recurrence-survival (for patients with recurrent glioblastoma) was analyzed with Cox regression. The impact of age, history (newly diagnosed vs. recurrent glioblastoma), number of Gliadel wafers implanted (0 vs. <8 vs. 8), resection extent (gross-total vs. partial) and adjuvant treatment (TMZ vs. other schemes/no adjuvant therapy) on the occurrence of AE and on the occurrence of implantation site-related AE (ISAE) was analyzed with the logistic regression model. Significance was set at p < 0.05. Multivariate analysis showed the only factor associated with longer survival, both for newly diagnosed and for recurrent GBM, was resection extent. Both patients with a higher number of wafers implanted and patients with recurrent tumors were significantly at risk for AE and ISAE. Patients with eight Gliadel wafers implanted had a 3-fold increased risk of AE and a 5.6-fold increased risk of ISAE, and patients with recurrent tumor had a 2.8-fold increased risk of AE and a 9.3-fold increased risk of ISAE. Adding Gliadel to standard treatment did not significantly improve the outcome. The toxicity after Gliadel use was significantly higher, both for patients with newly diagnosed and patients with recurrent glioblastoma.

  2. Wafer scale imprint uniformity evaluated by LSPR spectroscopy: a high volume characterization method for nanometer scale structures

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Lindstedt, Daniel Nilsson; Vig, Asger Laurberg


    numerical simulations of imprinted structures characterized by atomic force microscopy. There is a fair agreement between the two methods and the simulations enable the translation of optical spectra to critical dimensions of the physical structures, a concept known from scatterometry. The results...

  3. Prospective study of carmustine wafers in combination with 6-month metronomic temozolomide and radiation therapy in newly diagnosed glioblastoma: preliminary results. (United States)

    Salmaggi, Andrea; Milanesi, Ida; Silvani, Antonio; Gaviani, Paola; Marchetti, Marcello; Fariselli, Laura; Solero, Carlo Lazzaro; Maccagnano, Carmelo; Casali, Cecilia; Guzzetti, Sara; Pollo, Bianca; Ciusani, Emilio; Dimeco, Francesco


    Locoregional chemotherapy with carmustine wafers, positioned at surgery and followed by radiation therapy, has been shown to prolong survival in patients with newly diagnosed glioblastoma, as has concomitant radiochemotherapy with temozolomide. A combination of carmustine wafers with the Stupp treatment regimen has only been investigated in retrospective studies. In a single-institution prospective study, the authors assessed 12-month progression-free survival (PFS), toxicity, and overall survival in patients with glioblastoma treated with surgery, carmustine wafers, radiotherapy, and 6-month metronomic temozolomide chemotherapy. Thirty-five patients with de novo glioblastoma, between the ages of 18 and 70 years, and with Karnofsky Performance Scale scores of at least 70, were included in the study. Patients were followed monthly and assessed using MRI every 2 months. After a median follow-up of 15 months, the median time to tumor progression was 12.5 months and median survival was 17.8 months. Due to toxicity (mostly hematological), 7 patients had to prematurely stop temozolomide treatment. Twenty-two patients developed Grade 3 CD4(+) lymphocytopenia. Three patients developed oral-esophageal candidiasis, 2 developed pneumonia, and 1 developed a dorsolumbar zoster. Early intracranial hypertension was observed in 1 patient, and 1 was treated empirically for suspected brain abscess. One patient died of Legionella pneumonia soon after repeat surgery. Overall, this treatment schedule produced promising results in terms of PFS without a marked increase in toxicities as compared with the Stupp regimen. However, the gain in median survival using this schedule was less clear. Only prospective comparative trials will determine whether these preliminary results will translate into a long-term survival advantage with an acceptable toxicity profile.

  4. Investigations of the optical and EPR data and local structure for the trigonal tetrahedral Co2+ centers in LiGa5O8: Co2+ crystal (United States)

    He, Jian; Liao, Bi-Tao; Mei, Yang; Liu, Hong-Gang; Zheng, Wen-Chen


    In this paper, we calculate uniformly the optical and EPR data for Co2+ ion at the trigonal tetrahedral Ga3+ site in LiGa5O8 crystal from the complete diagonalization (of energy matrix) method founded on the two-spin-orbit-parameter model, where the contributions to the spectroscopic data from both the spin-orbit parameter of dn ion (in the classical crystal field theory) and that of ligand ions are contained. The calculated ten spectroscopic data (seven optical bands and three spin-Hamiltonian parameters g//, g⊥ and D) with only four adjustable parameters are in good agreement with the available observed values. Compared with the host (GaO4)5- cluster, the great angular distortion and hence the great trigonal distortion of (CoO4)6- impurity center obtained from the calculations are referred to the large charge and size mismatch substitution. This explains reasonably the observed great g-anisotropy Δg (= g// - g⊥) and zero-field splitting D for the (CoO4)6- cluster in LiGa5O8: Co2+ crystal.

  5. Ultraviolet-LIGA-based fabrication and characterization of a nonresonant drive-mode vibratory gyro/accelerometer (United States)

    Verma, Payal; Zaman Khan, Khamar; Khonina, Svetlana Nikolaevna; Kazanskiy, Nikolay Lvovich; Gopal, Ram


    A dual-purpose nonresonant 2-degrees of freedom (DOF) drive-mode and 1-DOF sense-mode vibratory gyro/accelerometer fabricated using the economical ultraviolet-lithographie-galvanoformung-abformung (UV-LIGA) fabrication process using SU-8 photoresist is reported. The dual-purpose device presented is capable of detecting acceleration at the lower-frequency band and angular rate at the operating frequency band thereby functioning as both accelerometer and gyroscope. This is achieved by designing the structure such that the frequency response of the drive oscillator has two drive resonances with a flat zone between them, while the sense oscillator has one resonance, which is deliberately placed in the flat region between the two drive resonances. For angular rate detection, the device is operated in the flat zone at the sense resonance frequency at which the device is less susceptible to frequency variations due to both environmental variation and fabrication imperfections and hence is said to be operating in robust mode. The steady-state response and discrimination for angular rate and acceleration sensing have been devised using analytical modeling. The fabrication process is optimized to realize a gyro/accelerometer that has a 9-μm-thick nickel structural layer and 4-μm capacitive gaps. The overall miniature device size is 2.0 mm×1.9 mm. The experimental frequency response of the fabricated devices shows drive-mode resonances at 2.85 and 4.96 kHz and sense resonance at 3.85 kHz compared to the respective design values of drive-mode resonance frequencies 2.97 and 4.81 kHz and sense resonance frequency of 4 kHz. To demonstrate the dual-purpose capability of the device, acceleration characterization has been carried out and presented. The fabricated sensor is packaged in a ceramic package and interfaced with a MS3110 differential capacitive read out IC to characterize the acceleration response of the sensor, using an out-of-plane shaker. The bandwidth for

  6. Soldagem por ponto no estado sólido de ligas leves Solid state spot welding of lightweight alloys

    Directory of Open Access Journals (Sweden)

    Leonardo Contri Campanelli


    Full Text Available A recente preocupação quanto às mudanças climáticas vem impulsionando pesquisas em eficiência energética dos meios de transportes no sentido de reduzir a emissão de gases. Uma das principais soluções consiste na redução do peso estrutural através da aplicação de novos materiais, como as ligas leves de alumínio e magnésio. Entretanto, novos usos ficam muitas vezes limitados pela dificuldade de união desses materiais. A técnica de soldagem por fricção e mistura (FSW é um processo de união no estado sólido que surge como uma alternativa viável para substituir ou complementar as tecnologias de união consagradas. Como uma junta contínua não é sempre a requisitada, duas tecnologias de união por ponto derivadas do FSW estão em desenvolvimento: soldagem por fricção e mistura por ponto (FSSW e soldagem por fricção por ponto (FSpW. Além de fornecerem juntas de elevada resistência e praticamente isentas de defeitos, estas técnicas apresentam alta eficiência energética, curto ciclo de soldagem, facilidade de automação e compatibilidade com o meio-ambiente, fazendo frente às técnicas convencionais de união por ponto, como a soldagem por resistência por ponto (RSW e a rebitagem.The recent concern about climate change has stimulated research into transport energy efficiency in order to reduce the emission of gases. One of the main solutions is to reduce the structural weight through the application of new materials, such as aluminum and magnesium lightweight alloys. However, new applications are often limited by the difficulty of joining these materials. Friction Stir Welding (FSW is a solid state joining technique that emerges as a viable alternative to replace or complement the established joining technologies. As a continuous weld is not always requested, two spot welding technologies derived from FSW are under development: Friction Stir Spot Welding (FSSW and Friction Spot Welding (FSpW. Besides providing

  7. Improvement of polycrystalline silicon wafer solar cell efficiency by forming nanoscale pyramids on wafer surface using a self-mask etching technique. (United States)

    Lin, Hsin-Han; Chen, Wen-Hwa; Hong, Franklin C-N


    The creation of nanostructures on polycrystalline silicon wafer surface to reduce the solar reflection can enhance the solar absorption and thus increase the solar-electricity conversion efficiency of solar cells. The self-masking reactive ion etching (RIE) was studied to directly fabricate nanostructures on silicon surface without using a masking process for antireflection purpose. Reactive gases comprising chlorine (Cl2), sulfur hexafluoride (SF6), and oxygen (O2) were activated by radio-frequency plasma in an RIE system at a typical pressure of 120-130 mTorr to fabricate the nanoscale pyramids. Poly-Si wafers were etched directly without masking for 6-10 min to create surface nanostructures by varying the compositions of SF6, Cl2, and O2 gas mixtures in the etching process. The wafers were then treated with acid (KOH:H2O = 1:1) for 1 min to remove the damage layer (100 nm) induced by dry etching. The damage layer significantly reduced the solar cell efficiencies by affecting the electrical properties of the surface layer. The light reflectivity from the surface after acid treatment could be significantly reduced to <10% for the wavelengths between 500 and 900 nm. The effects of RIE and surface treatment conditions on the surface nanostructures and the optical performance as well as the efficiencies of solar cells will be presented and discussed. The authors have successfully fabricated large-area (156 × 156 mm2) subwavelength antireflection structure on poly-Si substrates, which could improve the solar cell efficiency reproducibly up to 16.27%, higher than 15.56% using wet etching.

  8. The wettability between etching solutions and the surface of multicrystalline silicon wafer during metal-assisted chemical etching process (United States)

    Niu, Y. C.; Liu, Z.; Liu, X. J.; Gao, Y.; Lin, W. L.; Liu, H. T.; Jiang, Y. S.; Ren, X. K.


    In order to investigate the wettability of multicrystalline silicon (mc-Si) with the etching solutions during metal-assisted chemical etching process, different surface structures were fabricated on the p-type multi-wire slurry sawn mc-Si wafers, such as as-cut wafers, polished wafers, and wafers etched in different solutions. The contact angles of different etching solutions on the surfaces of the wafers were measured. It was noted that all contact angles of etching solutions were smaller than the corresponding ones of deionized water, but the contact angles of different etching solutions were quite different. Among the contact angles of the etching solutions of AgNO3-HF, H2O2-HF, TMAH and HNO3-HF, the contact angle of TMAH solution was much larger than the others and that of HNO3-HF solution was much smaller. It is suggested that the larger contact angle may lead to an unevenly etching of silicon wafer due to the long retention of big bubbles on the wafers in the etching reaction, which should be paid attention to and overcome.

  9. Iterative learning control for synchronization of reticle stage and wafer stage in step-and-scan lithographic equipment (United States)

    Li, Lan-lan; Hu, Song; Zhao, Li-xin; Ma, Ping


    Lithographic equipments are highly complex machines used to manufacture integrated circuits (ICs). To make larger ICs, a larger lens is required, which, however, is prohibitively expensive. The solution to this problem is to expose a chip not in one flash but in a scanning fashion. For step-and-scan lithographic equipment (wafer scanner), the image quality is decided by many factors, in which synchronization of reticle stage and wafer stage during exposure is a key one. In this paper, the principle of reticle stage and wafer stage was analyzed through investigating the structure of scanners, firstly. While scanning, the reticle stage and wafer stage should scan simultaneously at a high speed and the speed ratio is 1:4. Secondly, an iterative learning controller (ILC) for synchronization of reticle stage and wafer stage is presented. In the controller, a master-slave structure is used, with the wafer stage acting as the master, and the reticle stage as the slave. Since the scanning process of scanner is repetitive, ILC is used to improve tracking performance. A simple design procedure is presented which allows design of the ILC system for the reticle stage and wafer stage independently. Finally, performance of the algorithm is illustrated by simulated on the virtual stages (the reticle stage and wafer stage).The results of simulation experiments and theory analyzing demonstrate that using the proposed controller better synchronization performance can be obtained for the reticle stage and wafer stage in scanner. Theory analysis and experiment shows the method is reasonable and efficient.

  10. Avaliação da Capacidade de Decisão em Psiquiatria de Ligação

    Directory of Open Access Journals (Sweden)

    Filipe Lopes Vicente


    Full Text Available Introdução: Entre as funções do psiquiatra de ligação, encontra-se a avaliação da capacidade de decidir. Esta envolve a capacidade de fazer escolhas de forma autónoma e surge de forma relevante na prática clínica diária como pré-condição ao consentimento informado. Objetivos: Os autores pretendem rever o pro- cesso subjacente à avaliação da capacidade de decisão, assim como outra informação relevante publicada a este respeito. Métodos: Revisão não sistemática da literatura através da pesquisa eletrónica nos motores de busca Medline/Pubmed. Resultados: A capacidade de decidir apenas pode ser avaliada relativamente a uma decisão em particular, sendo que o seu resultado não é necessariamente estável ao longo do tempo. Da mesma forma, não existe nenhum diagnóstico que permita concluir, por si só, pela incapacidade para decidir ou que possibilite prescindir da sua avaliação. Depende de vários fatores: conteúdo, forma do pensa- mento e funções cognitivas. Pode igualmente ser influenciada pelo nível de instrução do indivíduo,  traços  da  personalidade,  estados emocionais/mecanismos de coping ou fatores circunstanciais. Qualquer  médico  deverá  estar  habilitado para  a  realização  desta  avaliação.  O  psiquiatra  de  ligação  deve  ser  envolvido  perante  a  suspeita  de  doença  mental  capaz de  prejudicar  a  capacidade  de  consentir ou  perante  a  necessidade  de  validar  uma avaliação já realizada. Appelbaum e Grisso propuseram  uma  avaliação  sistematizada segundo os seguintes critérios: a comunicação da escolha, b compreensão, c apreciação  e  d  processo  de  decisão  racional/ raciocínio.  Numa  tentativa  de  minimizar diferenças entre avaliadores, foram desenvolvidos vários instrumentos de avaliação, entre os quais se destaca a MacArthur Competence  Assessment  Tool.  Particularmente nos doentes com d

  11. Low-loss and flatband silicon-nanowire-based 5th-order coupled resonator optical waveguides (CROW) fabricated by ArF-immersion lithography process on a 300-mm SOI wafer (United States)

    Jeong, Seok-Hwan; Shimura, Daisuke; Simoyama, Takasi; Seki, Miyoshi; Yokoyama, Nobuyuki; Ohtsuka, Minoru; Koshino, Keiji; Horikawa, Tsuyoshi; Tanaka, Yu; Morito, Ken


    We present flatband, low-loss and low-crosstalk characteristics of Si-nanowire-based 5th-order coupled resonator optical waveguides (CROW) fabricated by ArF-immersion lithography process on a 300-mm silicon-on-insulator (SOI) wafer. We theoretically specified why phase controllability over Si-nanowire waveguides is prerequisite to attain desired spectral response, discussing spectral degradation by random phase errors during fabrication process. It was experimentally demonstrated that advanced patterning technology based on ArF-immersion lithography process showed extremely low phase errors even for Si-nanowire channel waveguides. As a result, the device exhibited extremely low loss of CROW. We believe these high-precision fabrication technologies based on 300-mm SOI wafer scale ArF-immersion lithography would be promising for several kinds of WDM multiplexers/demultiplexers having much complicated configurations and requiring much finer phase controllability.

  12. Análisis de la incidencia de la Teoría de la Identidad Colectiva en la posición de la Liga Árabe frente al reconocimiento de Somalilandia como Estado independiente


    Barrios Ibañez, Daniela


    Esta Monografía se centra en mostrar cómo el intento por conservar la identidad colectiva de la Liga de los Estados Árabes impide ceder ante el deseo de Somalilandia de ser reconocida como Estado independiente.

  13. Chemical strategies for modifications of the solar cell process, from wafering to emitter diffusion; Chemische Ansaetze zur Neuordnung des Solarzellenprozesses ausgehend vom Wafering bis hin zur Emitterdiffusion

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, Kuno


    The paper describes the classic standard industrial solar cell based on monocrystalline silicon and describes new methods of fabrication. The first is an alternative wafering concept using laser microjet cutting instead of multiwire cutting. This method originally uses pure, deionized water; it was modified so that the liquid jet will not only be a liquid light conductor but also a transport medium for etching fluids supporting thermal abrasion of silicon by the laser jet. Two etching fluids were tested experimentally; it was found that water-free fluids based on perfluorinated solvents with very slight additions of gaseous chlorine are superior to all other options. In the second section, the wet chemical process steps between wafering and emitter diffusion (i.e. the first high-temperature step) was to be modified. Alternatives to 2-propanol were to be found in the experimental part. Purification after texturing was to be rationalized in order to reduce the process cost, either by using less chemical substances or by achieving shorter process times. 1-pentanol and p-toluolsulfonic acid were identified as two potential alternatives to 2-propanol as texture additives. Finally, it could be shown that wire-cut substrates processed with the new texturing agents have higher mechanical stabilities than substrates used with the classic texturing agent 2-propanol. [German] Im ersten Kapitel wird die klassische Standard-Industrie-Solarzelle auf der Basis monokristallinen Siliziums vorgestellt. Der bisherige Herstellungsprozess der Standard-Industrie-Solarzelle, der in wesentlichen Teilen darauf abzielt, diese Verluste zu minimieren, dient als Referenz fuer die Entwicklung neuer Fertigungsverfahren, wie sie in dieser Arbeit vorgestellt werden. Den ersten thematischen Schwerpunkt bildet die Entwicklung eines alternativen Wafering-Konzeptes zum Multi-Drahtsaegen. Die Basis des neuen, hier vorgestellten Wafering-Prozesses bildet das Laser-Micro-Jet-Verfahren. Dieses System

  14. Novel SU-8 based vacuum wafer-level packaging for MEMS devices

    DEFF Research Database (Denmark)

    Murillo, Gonzalo; Davis, Zachary James; Keller, Stephan Urs


    This work presents a simple and low-cost SU-8 based wafer-level vacuum packaging method which is CMOS and MEMS compatible. Different approaches have been investigated by taking advantage of the properties of SU-8, such as chemical resistance, optical transparence, mechanical reliability...... and versatility. A novel technique of wafer level adhesive bonding, which uses SU-8 as structural and adhesive material, has been developed and successfully demonstrated. Optical inspection and SEM images were used in order to measure the package lid bending and probe the encapsulation sealing. In addition......, an indirect vacuum level measurement has been carried out by comparing the different quality factors of a test cantilever resonator when this element is packed or unpacked....

  15. A new method for wafer quality monitoring using semiconductor process big data (United States)

    Sohn, Younghoon; Lee, Hyun; Yang, Yusin; Jun, Chungsam


    In this paper we proposed a new semiconductor quality monitoring methodology - Process Sensor Log Analysis (PSLA) - using process sensor data for the detection of wafer defectivity and quality monitoring. We developed exclusive key parameter selection algorithm and user friendly system which is able to handle large amount of big data very effectively. Several production wafers were selected and analyzed based on the risk analysis of process driven defects, for example alignment quality of process layers. Thickness of spin-coated material can be measured using PSLA without conventional metrology process. In addition, chip yield impact was verified by matching key parameter changes with electrical die sort (EDS) fail maps at the end of the production step. From this work, we were able to determine that process robustness and product yields could be improved by monitoring the key factors in the process big data.

  16. EEI`s wafer-cell bipolar battery: Versatile technology for a variety of military systems

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.T.; Klein, M.G.; Reisner, D.E. [Electro Energy, Inc., Danbury, CT (United States)


    A new versatile cell design based on stackable wafer cells is described which forms the unit building block of a new generation of bipolar battery systems for a wide variety of military applications. Current is transported across an outer envelope of conductive plastic film. This innovative bipolar design approach offers improved energy density based on more efficient packaging in prismatic containers as well as elimination of cell hardware. Higher power capability is achieved from the intrinsic low resistance operation in a bipolar mode. These performance improvements are achieved in a low-cost package by virtue of the design simplicity and use of non-graphitic plastic-bonded electrodes. EEI has demonstrated the viability of the wafer cell approach in Ni-MH with sealed cell cycle life in excess of 2,000 cycles. Results are also reported for Ag-MH.

  17. Fabrication of capacitive micromachined ultrasonic transducers based on adhesive wafer bonding technique (United States)

    Li, Zhenhao; Wong, Lawrence L. P.; Chen, Albert I. H.; Na, Shuai; Sun, Jame; Yeow, John T. W.


    This paper reports the fabrication process of wafer bonded capacitive micromachined ultrasonic transducers (CMUTs) using photosensitive benzocyclobutene as a polymer adhesive. Compared with direct bonding and anodic bonding, polymer adhesive bonding provides good tolerance to wafer surface defects and contamination. In addition, the low process temperature of 250 °C is compatible with standard CMOS processes. Single-element CMUTs consisting of cells with a diameter of 46 µm and a cavity depth of 323 nm were fabricated. In-air and immersion acoustic characterizations were performed on the fabricated CMUTs, demonstrating their capability for transmitting and receiving ultrasound signals. An in-air resonance frequency of 5.47 MHz was measured by a vibrometer under a bias voltage of 300 V.

  18. Wafer-Level Patterned and Aligned Polymer Nanowire/Micro- and Nanotube Arrays on any Substrate

    KAUST Repository

    Morber, Jenny Ruth


    A study was conducted to fabricate wafer-level patterned and aligned polymer nanowire (PNW), micro- and nanotube arrays (PNT), which were created by exposing the polymer material to plasma etching. The approach for producing wafer-level aligned PNWs involved a one-step inductively coupled plasma (ICP) reactive ion etching process. The polymer nanowire array was fabricated in an ICP reactive ion milling chamber with a pressure of 10mTorr. Argon (Ar), O 2, and CF4 gases were released into the chamber as etchants at flow rates of 15 sccm, 10 sccm, and 40 sccm. Inert gasses, such as Ar-form positive ions were incorporated to serve as a physical component to assist in the material degradation process. One power source (400 W) was used to generate dense plasma from the input gases, while another power source applied a voltage of approximately 600V to accelerate the plasma toward the substrate.

  19. On the design of GaN vertical MESFETs on commercial LED sapphire wafers (United States)

    Atalla, Mahmoud R. M.; Noor Elahi, Asim M.; Mo, Chen; Jiang, Zhenyu; Liu, Jie; Ashok, S.; Xu, Jian


    Design of GaN-based vertical metal-semiconductor field-effect transistors (MESFETs) on commercial light-emitting-diode (LED) epi-wafers has been proposed and proof of principle devices have been fabricated. In order to better understand the IV curves, these devices have been simulated using the charge transport model. It was found that shrinking the drain pillar size would significantly help in reaching cut-off at much lower gate bias even at high carrier concentration of unintentionally doped GaN and considerable leakage current caused by the Schottky barrier lowering. The realization of these vertical MESFETs on LED wafers would allow their chip-level integration. This would open a way to many intelligent lighting applications like on-chip current regulator and signal regulation/communication in display technology.

  20. Silicon Wafer Fabrication and Microchannel for Cooling System in ALICE ITS

    CERN Document Server

    Pasuwan, Patrawan


    My summer student project covered details of the upgrade of Inner Tracking System (ITS) of the ALICE detector. The tasks are divided in two parts. First was on silicon wafer dicing technology and its resistivity under the supervision of Petra Riedler. Next was on silicon wafer microfabrication and cooling system in microchannel under the supervision of Andrea Francescon. ITS upgrade was proposed for better detection performance and reduction of budget. Detectors in the ITS are composed of monolithic silicon pixel chips. The thickness of the chips was proposed to be 50 μm so that particles that pass through them do not lose too much momentum. Working with very thin chips requires suitable dicing technology. Sum- mary of dicing technology is proposed for the most suitable dicing technique. Properties of the chip can be denoted by observing its resistivity. Literature reviews on surface resistivity profile measurement is represented for consideration. Cooling system is very important for the detector. Fluid t...

  1. Silicon Chemical Vapor Deposition Process Using a Half-Inch Silicon Wafer for Minimal Manufacturing System (United States)

    Li, Ning; Habuka, Hitoshi; Ikeda, Shin-ichi; Hara, Shiro

    A chemical vapor deposition reactor for producing thin silicon films was designed and developed for achieving a new electronic device production system, the Minimal Manufacturing, using a half-inch wafer. This system requires a rapid process by a small footprint reactor. This was designed and verified by employing the technical issues, such as (i) vertical gas flow, (ii) thermal operation using a highly concentrated infrared flux, and (iii) reactor cleaning by chlorine trifluoride gas. The combination of (i) and (ii) could achieve a low heating power and a fast cooling designed by the heat balance of the small wafer placed at a position outside of the reflector. The cleaning process could be rapid by (iii). The heating step could be skipped because chlorine trifluoride gas was reactive at any temperature higher than room temperature.

  2. Uncertainty of a hybrid surface temperature sensor for silicon wafers and comparison with an embedded thermocouple. (United States)

    Iuchi, Tohru; Gogami, Atsushi


    We have developed a user-friendly hybrid surface temperature sensor. The uncertainties of temperature readings associated with this sensor and a thermocouple embedded in a silicon wafer are compared. The expanded uncertainties (k=2) of the hybrid temperature sensor and the embedded thermocouple are 2.11 and 2.37 K, respectively, in the temperature range between 600 and 1000 K. In the present paper, the uncertainty evaluation and the sources of uncertainty are described.

  3. Fabrication of a mechanically aligned single-wafer MEMS turbine with turbocharger (United States)

    Pelekies, S. O.; Schuhmann, T.; Gardner, W. G.; Camacho, A.; Protz, J. M.


    We describe the fabrication of a turbocharged, microelectromechanical system (MEMS) turbine. The turbine will be part of a standalone power unit and includes extra layers to connect the turbine to a generator. The project goal is to demonstrate the successful combination of several features, namely: silicon fusion bonding (SFB), a micro turbocharger [2], two rotors, mechanical alignment between two wafers [1], and the use of only one 5" silicon wafer. The dimension of the actual turbine casing will be 14mm. The turbine rotor will have a diameter of 8mm. Given these dimensions, MEMS processes are an adequate way to fabricate the device, but it will be necessary to stack up seven different layers to build the turbine, as it is not possible to construct it out of one thick wafer. SFB will be used for bonding because it permits the great precision necessary for high quality alignment. Yet a more precise alignment will be necessary between the layers that contain the turbine rotor, to decrease imbalance and guarantee operation at a very high rpm. To achieve these tight tolerances, a mechanical alignment feature announced by Liudi Jiang [1] is used. The alignment accuracy is expected to be around 200nm. Despite the fact that the turbine consists of multiple layers, it will be fabricated on only one silicon-on-insulator (SOI) wafer. As a result, all layers are exposed to the same process flow. The fabrication process includes MEMS technology as photolithography, nine deep reactive ion etching (DRIE) steps, and six SFB operations. A total of 14 masks are necessary for the fabrication.

  4. Improved delivery of the anticancer agent citral using BSA nanoparticles and polymeric wafers

    Directory of Open Access Journals (Sweden)

    White B


    Full Text Available Benjamin White,1 Anna Evison,1 Eszter Dombi,1 Helen E Townley1,2 1Nuffield Department of Obstetrics and Gynaecology, Women’s Centre, John Radcliffe Hospital, 2Department of Engineering Science, Oxford University, Oxford, UK Abstract: Rhabdomyosarcoma (RMS is the most common soft tissue sarcoma in children, with a 5-year survival rate of between 30 and 65%. Standard treatment involves surgery, radiation treatment, and chemotherapy. However, there is a high recurrence rate, particularly from locoregional spread. We investigated the use of the natural compound citral (3,7-dimethyl-2,6-octadienal, which can be found in a number of plants, but is particularly abundant in lemon grass (Cymbopogon citratus oil, for activity against immortalized RMS cells. Significant cancer cell death was seen at concentrations above 150 μM citral, and mitochondrial morphological changes were seen after incubation with 10 μM citral. However, since citral is a highly volatile molecule, we prepared albumin particles by a desolvation method to encapsulate citral, as a means of stabilization. We then further incorporated the loaded nanoparticles into a biodegradable polyanhydride wafer to generate a slow release system. The wafers were shown to degrade by 50% over the course of 25 days and to release the active compound. We therefore propose the use of the citral-nanoparticle-polymer wafers for implantation into the tumor bed after surgical removal of a sarcoma as a means to control locoregional spread due to any remaining cancerous cells. Keywords: citral, nanoparticle, wafer, biodegradable, mitochondria, toroidal, cancer, rhabdomyosarcoma, Cymbopogon citratus

  5. Removal of resist film from wafer surface by steam-water mixture jet (United States)

    Mashiko, Takashi; Sanada, Toshiyuki; Nishiyama, Itsuo; Horibe, Hideo


    We have shown that the steam-water mixture jet, a two-fluid jet with its carrier gas being steam, exhibits high cleaning performance when sprayed onto a target. This is a promising technique which requires only simple apparatus and little or no chemicals, but the cleaning mechanism remains unknown. We have conducted a series of experiments to elucidate the mechanism and learn how to meet given industrial requirements (e.g., set parameters for desired detergency). In our recent experiment, we adopted a resist-coated silicon wafer as the target and evaluated the jet performance of resist removal from the wafer. The removal performance proved to be a decreasing function of the resist hardness and of the resist-wafer adhesivity, and an increasing function of the jet duration. These results suggest that the resist removal by the steam-water mixture jet mainly consists of physical processes (e.g., peel-off process), in contrast to the traditional resist-removal techniques utilizing chemical reactions.

  6. Improved delivery of the anticancer agent citral using BSA nanoparticles and polymeric wafers. (United States)

    White, Benjamin; Evison, Anna; Dombi, Eszter; Townley, Helen E


    Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children, with a 5-year survival rate of between 30 and 65%. Standard treatment involves surgery, radiation treatment, and chemotherapy. However, there is a high recurrence rate, particularly from locoregional spread. We investigated the use of the natural compound citral (3,7-dimethyl-2,6-octadienal), which can be found in a number of plants, but is particularly abundant in lemon grass (Cymbopogon citratus) oil, for activity against immortalized RMS cells. Significant cancer cell death was seen at concentrations above 150 μM citral, and mitochondrial morphological changes were seen after incubation with 10 μM citral. However, since citral is a highly volatile molecule, we prepared albumin particles by a desolvation method to encapsulate citral, as a means of stabilization. We then further incorporated the loaded nanoparticles into a biodegradable polyanhydride wafer to generate a slow release system. The wafers were shown to degrade by 50% over the course of 25 days and to release the active compound. We therefore propose the use of the citral-nanoparticle-polymer wafers for implantation into the tumor bed after surgical removal of a sarcoma as a means to control locoregional spread due to any remaining cancerous cells.

  7. A novel sandwich capacitive accelerometer with a symmetrical structure fabricated from a D-SOI wafer (United States)

    Zhou, Xiaofeng; Che, Lufeng; Wu, Jian; Li, Xiaolin; Wang, Yuelin


    This paper presents a novel sandwich capacitance accelerometer with a symmetrical double-sided beam-mass structure. The symmetrical beam-mass structure is fabricated from a double-device-layer silicon-on-insulate (D-SOI) wafer. The proof mass is suspended by eight beams at the corners on both sides. The beams are fabricated at the device layers of the SOI wafer; the cross-section of the beams is a standard trapezoid. The thickness of the beams can be well controlled because it is determined by the thickness of the device layer in the SOI wafer, and there is no dry etching process in the accelerometer fabrication. The resonance frequency of the developed accelerometer is measured in an open-loop system by a network analyzer. The quality factor and the resonant frequency are 18 and 812 Hz, respectively. The accelerometer has an opened-loop capacitance sensitivity of 8.7 pF g-1, a closed-loop sensitivity of 1.39 V g-1 and a nonlinearity of 0.49% over the range of 1 g. The measured input, referred to as the noise floor of the accelerometers, with an interface circuit is 2.4 µg (√Hz)-1 (0-100 Hz).

  8. High temperature performance evaluation of a hypersonic engine ceramic wafer seal (United States)

    Steinetz, Bruce M.


    Leakage rates of an innovative hypersonic engine seal were measured using a specially developed static high temperature seal test fixture at NASA Lewis Research Center. The three foot long structural panel-edge seal is designed to minimize leakage of high temperature, high pressure gases past the movable panels of advanced ramjet/scramjet engines. The seal is made of a stack of precision machined ceramic wafer pieces that are inserted into a closely conforming seal channel in the movable engine panel. The wafer seal accommodates the significant distortions in the adjacent engine walls through relative sliding between adjacent wafers. Seal leakage rates are presented for engine simulated air temperatures up to 1350 F and for engine pressures up to 100 psi. Leakage rates are also presented for the seal, sealing both a flat wall condition, and an engine simulated distorted wall condition in which the distortion was 0.15 in. in only an 18 in. span. Seal leakage rates were low, meeting an industry-established tentative leakage limit for all combinations of temperature, pressure, and wall conditions considered. Comparisons are made between the measured leakage rates and leakage rates predicted using a seal leakage model developed from externally-pressurized gas film bearing theory.

  9. Materials with a buried C[sub 60] layer produced by direct wafer bonding

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Q.Y.; Eom, C.B.; Goesele, U. (Duke Univ., Durham, NC (United States). School of Engineering); Hebard, A.F. (AT and T Bell Laboratories, Murray Hill, NJ (United States))


    The C[sub 60] molecule has received close attention in the research community because of its high symmetry and unusual properties. Since in combination with other elements it can be made into super conductors, ferromagnets, and photoconductors, there are expectations that a broad range of possible applications may be possible. Si wafers covered with a sublimed C[sub 60] layer have been directly bonded to bare or oxidized Si wafers at room temperature via Van der Waals attraction forces. The interface energies of the bonded pairs increase during storage in air at room temperature and approach saturated values after [approximately]200 h. The typical saturated interface energy of C[sub 60]/SiO[sub 2] ([approximately]40 erg/cm[sup 2]) is higher than that of C[sub 60]/Si (20--30 erg/cm[sup 2]). Other material combinations having a C[sub 60] buried layer may also be realized by wafer bonding for specific applications.

  10. Chip yield for FETs fabricated on low-surface-defect GaAs wafers grown by a new MBE system

    Energy Technology Data Exchange (ETDEWEB)

    Kato, S.; Shigeta, J.; Miyata, T.; Kawata, M. (Central Research Laboratory, Hitachi Ltd., Tokyo (Japan)); Tamura, N. (Kasado Works, Hitachi Ltd., Yamachuci (Japan)); Takahashi, K. (Mechanical Research Laboratory, Hitachi Ltd., Ibaraki (Japan))


    A very low defect density is achieved with a new MBE system, in which the diameter of the top-heated Ga cell is as big as 60 mm and the distance between the wafer and the cell is optimized at 450 mm by simulation. This system grows GaAs wafers with a defect density of 14.6 cm[sup -2] for defects larger than 0.67 [mu]m[sup 2]. Our chip yield estimation for field effect transistors in the LSIs fabricated on the wafers shows that the grown wafer can integrate 100,000 FETs if each FET gate is 0.3 [mu]m long and 5 [mu]m wide and a chip yield of 42% is assumed

  11. New plant designs for aqueous etching and electroforming of wafers; Neues modulares Anlagenkonzept fuer nasschemische Aetzprozesse und die Wafergalvanoformung

    Energy Technology Data Exchange (ETDEWEB)

    Guttmann, Markus; Kaiser, Konradin; Muth, Stephanie [Karlsruher Institut fuer Technologie, Karlsruhe (Germany). Inst. fuer Mikrostrukturtechnik; Moritz, Hans [silicet AG, Lohfelden (Germany); Schmidt, Ralf; Zwanzig, Michael [Fraunhofer-Institut fuer Zuverlaessigkeit und Mikrointegration (IZM), Berlin (Germany); Hofmann, Lutz [TU Chemnitz (Germany). Zentrum fuer Mikrotechnologien; Schubert, Ina [Fraunhofer-Einrichtung fuer Elektronische Nanosysteme (ENAS), Chemnitz (Germany)


    In order to carry out a study of wafer patterning, equipment was developed for safe handling of silicon wafers from 2 to 8 inch diameters. The unit can be safely and relatively straightforwardly operated by personnel, using a wide range of etchants and electrochemical deposition processes. The design also allows the effects of electrolyte flowrate in the process chamber confronting the silicon wafer, to be assessed. These features were utilised to study copper and nickel electrodeposition to pattern the wafer surface. (orig.) [German] Zur Untersuchung der Strukturierung von Wafern wurde eine Prozesseinheit zur bruchsicheren Aufnahme von Siliziumwafern mit Durchmessern zwischen zwei und acht Zoll entwickelt. Die Einheit kann relativ einfach und mit hoher Sicherheit fuer die handhabenden Personen mit den unterschiedlichsten Medien zum Aetzen oder galvanotechnischen Aufbau betrieben werden. Die Anordnung ermoeglicht zudem die gezielte Beeinflussung der Stroemung im Prozessraum vor der Waferoberflaeche. Die Moeglichkeiten zur Untersuchung werden an der Nickel- und Kupferabscheidung zur Herstellung von Strukturen aufgezeigt. (orig.)

  12. Three-dimensional transient model for time-domain free-carrier absorption measurement of excess carriers in silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Shengdong; Huang, Qiuping [Institute of Optics and Electronics, Chinese Academy of Sciences, P. O. Box 350, Shuangliu, Chengdu, Sichuan 610209 (China); University of the Chinese Academy of Sciences, Beijing 100039 (China); Li, Bincheng, E-mail: [Institute of Optics and Electronics, Chinese Academy of Sciences, P. O. Box 350, Shuangliu, Chengdu, Sichuan 610209 (China)


    A three-dimensional transient model for time-domain (modulated) free-carrier absorption (FCA) measurement was developed to describe the transport dynamics of photo-generated excess carriers in silicon (Si) wafers. With the developed transient model, numerical simulations were performed to investigate the dependences of the waveforms of the transient FCA signals on the electronic transport parameters of Si wafers and the geometric parameters of the FCA experiment. Experimental waveforms of FCA signals of both n- and p-type Si wafers with resistivity ranging 1–38 Ω·cm were then fitted to the three-dimensional transient model to extract simultaneously and unambiguously the transport parameters of Si wafers, namely, the carrier lifetime, the carrier diffusion coefficient, and the front surface recombination velocity via multi-parameter fitting. A basic agreement between the extracted parameter values and the literature values was obtained.

  13. Control of Gene Expression in Leptospira spp. by Transcription Activator-Like Effectors Demonstrates a Potential Role for LigA and LigB in Leptospira interrogans Virulence. (United States)

    Pappas, Christopher J; Picardeau, Mathieu


    Leptospirosis is a zoonotic disease that affects ∼1 million people annually, with a mortality rate of >10%. Currently, there is an absence of effective genetic manipulation tools for targeted mutagenesis in pathogenic leptospires. Transcription activator-like effectors (TALEs) are a recently described group of repressors that modify transcriptional activity in prokaryotic and eukaryotic cells by directly binding to a targeted sequence within the host genome. To determine the applicability of TALEs within Leptospira spp., two TALE constructs were designed. First, a constitutively expressed TALE gene specific for the lacO-like region upstream of bgaL was trans inserted in the saprophyte Leptospira biflexa (the TALEβgal strain). Reverse transcriptase PCR (RT-PCR) analysis and enzymatic assays demonstrated that BgaL was not expressed in the TALEβgal strain. Second, to study the role of LigA and LigB in pathogenesis, a constitutively expressed TALE gene with specificity for the homologous promoter regions of ligA and ligB was cis inserted into the pathogen Leptospira interrogans (TALElig). LigA and LigB expression was studied by using three independent clones: TALElig1, TALElig2, and TALElig3. Immunoblot analysis of osmotically induced TALElig clones demonstrated 2- to 9-fold reductions in the expression levels of LigA and LigB, with the highest reductions being noted for TALElig1 and TALElig2, which were avirulent in vivo and nonrecoverable from animal tissues. This study reconfirms galactosidase activity in the saprophyte and suggests a role for LigA and LigB in pathogenesis. Collectively, this study demonstrates that TALEs are effective at reducing the expression of targeted genes within saprophytic and pathogenic strains of Leptospira spp., providing an additional genetic manipulation tool for this genus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. "De pequenino é que se torce o pepino": a infância nos programas eugênicos da Liga Brasileira de Higiene Mental "As the twig is bent, so is the tree inclined": children and the Liga Brasileira de Higiene Mental’s eugenic programs

    Directory of Open Access Journals (Sweden)

    José Roberto Franco Reis


    Full Text Available Este artigo propõe-se a discutir as propostas de intervenção na problemática infantil apresentadas pela Liga Brasileira de Higiene Mental (LBHM, instituição criada no começo da década de 1920 que reunia a elite da psiquiatria brasileira, mas também alguns médicos e intelectuais em geral. Fundada num momento de afirmação, no campo psiquiátrico, da perspectiva preventiva, a LBHM vai incorporar ao seu arsenal teórico os temas básicos da higiene mental e da eugenia, tendo em vista o seu objetivo maior de colaborar no "saneamento racial" brasileiro. Assim, é a partir desse objetivo e vendo na criança um "pré-cidadão", "peça fundamental do homem do futuro", que os psiquiatras da liga incluem a questão infantil nos seus projetos, passando a considerar imperiosa a necessidade de cuidados desde a mais tenra idade.Created in the early 1920s, at a moment when the country’s psychiatric field was embracing the preventive outlook, the Liga Brasileira de Higiene Mental included within its members the elite of Brazilian psychiatry, along with a number of physicians and intellectuals. The article discusses the institution’s proposals for intervention among children. The league ended up incorporating into its theoretical arsenal the basic themes of mental hygiene and eugenics as part of its general goal of collaborating in Brazil’s process of "racial sanitation". With this objective in mind, and viewing the child as a "pre-citizen" who is a "fundamental part within the man of the future", league members included the children’s issue in their projects and saw an imperative need for mental health care from early ages on.

  15. High-throughput characterization of stresses in thin film materials libraries using Si cantilever array wafers and digital holographic microscopy. (United States)

    Lai, Y W; Hamann, S; Ehmann, M; Ludwig, A


    We report the development of an advanced high-throughput stress characterization method for thin film materials libraries sputter-deposited on micro-machined cantilever arrays consisting of around 1500 cantilevers on 4-inch silicon-on-insulator wafers. A low-cost custom-designed digital holographic microscope (DHM) is employed to simultaneously monitor the thin film thickness, the surface topography and the curvature of each of the cantilevers before and after deposition. The variation in stress state across the thin film materials library is then calculated by Stoney's equation based on the obtained radii of curvature of the cantilevers and film thicknesses. DHM with nanometer-scale out-of-plane resolution allows stress measurements in a wide range, at least from several MPa to several GPa. By using an automatic x-y translation stage, the local stresses within a 4-inch materials library are mapped with high accuracy within 10 min. The speed of measurement is greatly improved compared with the prior laser scanning approach that needs more than an hour of measuring time. A high-throughput stress measurement of an as-deposited Fe-Pd-W materials library was evaluated for demonstration. The fast characterization method is expected to accelerate the development of (functional) thin films, e.g., (magnetic) shape memory materials, whose functionality is greatly stress dependent. © 2011 American Institute of Physics

  16. A Procedure to Determine and Correct for Transmission Line Resistances for Direct Current On-Wafer Measurements (United States)


    device, such as a bipolar junction transistor ( BJT ), a metal oxide semiconductor field effect transistor (MOSFET), or a high electron mobility...VDS_mesh,IDS,[0:.05:.5],’:’); 12 List of Symbols, Abbreviations, and Acronyms BJT bipolar junction transistor DC direct current DUT device... transistor (HEMT), when measured on-wafer, may be measured using two separate power lines with ground-signal-ground (GSG) on-wafer probes. Each power

  17. A 90 años de la fundación de la Liga Feminista Costarricense: los derechos políticos

    Directory of Open Access Journals (Sweden)

    Marta E. Solano Arias


    Full Text Available : Repaso de los derechos políticos de las mujeres con motivo del 90 aniversario de la fundación de la Liga Feminista Costarricense el 12 de octubre de 1923 en el Colegio Superior de Señoritas. El artículo ofrece un breve recorrido histórico de la participación de mujeres en hechos sociales y políticos relacionados con procesos electorales y la demanda del derecho el sufragio para las mujeres durante las primeras décadas del siglo XX y hasta 1925 en Costa Rica. Destaca algunas acciones de dos sufragistas descollantes durante los años 1912 a 1925, Ángela Acuña y Sara Casal.

  18. Doenças sexualmente transmissíveis e o HIV/AIDS: enfermagem discutindo essas ligações perigosas para as mulheres

    Directory of Open Access Journals (Sweden)

    Iara de Moraes Xavier


    Full Text Available Este artigo tem como objetivo principal discutir as ligações perigosas entre as DSTs e o HIV/AIDS pelo prisma do gênero e da sexualidade. Apresenta a feminização da AIDS no Brasil como produto das relações sociais, econômicas, políticas e culturais. Pesquisa descritiva exploratória de natureza qualitativa. Focaliza mulheres com HIV/AIDS que se contaminaram através de relações sexuais com parceiros fixos e únicos. Conclui que o cuidado de enfermagem, no contexto do processo saúde-doença, constitui-se em uma das principais oportunidades para a (o enfermeira (o trabalhar o diagnóstico precoce, o tratamento e a prevenção das DSTs e da AIDS.

  19. A técnica de dopagem no tratamento da zona de interface: ligações entre concreto novo e velho

    Directory of Open Access Journals (Sweden)

    Ana Paula Moreno Trigo

    Full Text Available Para que as estruturas de concreto alcancem uma vida útil adequada é necessário avaliar a durabilidade e considerar a manutenção das mesmas. Isso tem estimulado o desenvolvimento de tecnologias destinadas a solucionar a problemática de peças deterioradas ou danificadas. Este trabalho analisa o comportamento da zona de interface entre concreto novo e velho após a escarificação do concreto velho (tratamento físico e o emprego da técnica de dopagem (tratamento químico. A técnica de dopagem consiste na impregnação de pó por via seca ou pasta de alto desempenho, seguida do lançamento de concreto novo, ou no lançamento direto de um concreto novo com características de alto desempenho. O desempenho dessa ligação foi avaliado por meio de ensaios de tração na flexão, até a ruptura, em corpos de prova prismáticos de concreto simples (fck = 20 MPa e em seguida remoldados. A partir dos resultados, verificou-se que a ruptura dos corpos de prova recuperados ocorreu fora da região de interface e que as resistências à flexão desse concreto foram mantidas tais quais as originais, demonstrando a eficácia do procedimento na ligação entre concreto novo e velho.

  20. Meso-scale machining capabilities and issues

    Energy Technology Data Exchange (ETDEWEB)



    Meso-scale manufacturing processes are bridging the gap between silicon-based MEMS processes and conventional miniature machining. These processes can fabricate two and three-dimensional parts having micron size features in traditional materials such as stainless steels, rare earth magnets, ceramics, and glass. Meso-scale processes that are currently available include, focused ion beam sputtering, micro-milling, micro-turning, excimer laser ablation, femto-second laser ablation, and micro electro discharge machining. These meso-scale processes employ subtractive machining technologies (i.e., material removal), unlike LIGA, which is an additive meso-scale process. Meso-scale processes have different material capabilities and machining performance specifications. Machining performance specifications of interest include minimum feature size, feature tolerance, feature location accuracy, surface finish, and material removal rate. Sandia National Laboratories is developing meso-scale electro-mechanical components, which require meso-scale parts that move relative to one another. The meso-scale parts fabricated by subtractive meso-scale manufacturing processes have unique tribology issues because of the variety of materials and the surface conditions produced by the different meso-scale manufacturing processes.

  1. Microhardness of Ni-Cr alloys under different casting conditions Microdureza de ligas de Ni-Cr fundidas sob diferentes condições

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    José Roberto de Oliveira Bauer


    Full Text Available This study evaluated the microhardness of Ni-Cr alloys used in fixed prosthodontics after casting under different conditions. The casting conditions were: (1-flame/air torch flame made of a gas/oxygen mixture and centrifugal casting machine in a non-controlled casting environment; (2-induction/argon electromagnetic induction in an environment controlled with argon; (3-induction/vacuum electromagnetic induction in a vacuum environment; (4-induction/air electromagnetic induction in a non-controlled casting environment. The 3 alloys used were Ni-Cr-Mo-Ti, Ni-Cr-Mo-Be, and Ni-Cr-Mo-Nb. Four castings with 5 cylindrical, 15 mm-long specimens (diameter: 1.6 mm in each casting ring were prepared. After casting, the specimens were embedded in resin and polished for Vickers microhardness (VH measurements in a Shimadzu HMV-2 (1,000 g for 10 s. A total of 5 indentations were done for each ring, one in each specimen. The data was subjected to two-way ANOVA and Tukey's multiple comparison tests (alpha = 0.05. The VH values of Ni-Cr-Mo-Ti (422 ± 7.8 were statistically higher (p 0.05 and lower than the values obtained in the conditions induction/air and flame/air torch (p 0.05. The microhardness of the alloys is influenced by their composition and casting method. The hardness of the Ni-Cr alloys was higher when they were cast with the induction/air and flame/air torch methods.Este estudo avaliou a microdureza de ligas de Ni-Cr usadas em prótese fixa fundidas sob diferentes condições. As condições de fundição foram: (1-maçarico chama composta por uma mistura de gás/oxigênio e centrífuga sem o controle do ambiente de fundição; (2-indução/argônio indução eletromagnética com o ambiente controlado com argônio; (3-indução/vácuo indução eletromagnética com o ambiente sob vácuo; (4-indução/ar indução eletromagnética sem o controle da atmosfera. Foram utilizadas três ligas: Ni-Cr-Mo-Ti, Ni-Cr-Mo-Be e Ni-Cr-Mo-Nb. Foram realizadas 4

  2. Aberration-corrected transmission electron microscopy analyses of GaAs/Si interfaces in wafer-bonded multi-junction solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Häussler, Dietrich [Institute for Materials Science, Christian-Albrechts-University Kiel, Kaiserstraße 2, 24143 Kiel (Germany); Houben, Lothar [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Research Centre Juelich GmbH, 52425 Juelich (Germany); Essig, Stephanie [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg (Germany); Kurttepeli, Mert [Institute for Materials Science, Christian-Albrechts-University Kiel, Kaiserstraße 2, 24143 Kiel (Germany); Dimroth, Frank [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstraße 2, 79110 Freiburg (Germany); Dunin-Borkowski, Rafal E. [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Research Centre Juelich GmbH, 52425 Juelich (Germany); Jäger, Wolfgang, E-mail: [Institute for Materials Science, Christian-Albrechts-University Kiel, Kaiserstraße 2, 24143 Kiel (Germany)


    Aberration-corrected scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) investigations have been applied to investigate the structure and composition fluctuations near interfaces in wafer-bonded multi-junction solar cells. Multi-junction solar cells are of particular interest since efficiencies well above 40% have been obtained for concentrator solar cells which are based on III-V compound semiconductors. In this methodologically oriented investigation, we explore the potential of combining aberration-corrected high-angle annular dark-field STEM imaging (HAADF-STEM) with spectroscopic techniques, such as EELS and energy-dispersive X-ray spectroscopy (EDXS), and with high-resolution transmission electron microscopy (HR-TEM), in order to analyze the effects of fast atom beam (FAB) and ion beam bombardment (IB) activation treatments on the structure and composition of bonding interfaces of wafer-bonded solar cells on Si substrates. Investigations using STEM/EELS are able to measure quantitatively and with high precision the widths and the fluctuations in element distributions within amorphous interface layers of nanometer extensions, including those of light elements. Such measurements allow the control of the activation treatments and thus support assessing electrical conductivity phenomena connected with impurity and dopant distributions near interfaces for optimized performance of the solar cells. - Highlights: • Aberration-corrected TEM and EELS reveal structural and elemental profiles across GaAs/Si bond interfaces in wafer-bonded GaInP/GaAs/Si - multi-junction solar cells. • Fluctuations in elemental concentration in nanometer-thick amorphous interface layers, including the disrubutions of light elements, are measured using EELS. • The projected widths of the interface layers are determined on the atomic scale from STEM-HAADF measurements. • The effects of atom and ion beam activation treatment on the bonding

  3. Restauração metalocerâmica: um estudo comparativo da compatibilidade térmica de ligas Ni-Cr e porcelanas odontológicas

    Directory of Open Access Journals (Sweden)

    ROLLO João Manuel Domingos de Almeida


    Full Text Available Uma das aplicações tecnológicas em que é necessário haver compatibilidade entre um material cerâmico e um material metálico é a confecção de restaurações odontológicas do tipo metalocerâmica. Neste caso, uma porcelana é fundida sobre um substrato metálico para obtenção da prótese de um dente. O requisito fundamental para o sucesso da união metalocerâmica é a adequação dos coeficientes de expansão térmica de cada um dos materiais, de forma a se obter um estado de tensão de compressão adequado na camada cerâmica. Este trabalho propôs-se a levantar as curvas de expansão térmica de ligas Ni-Cr e porcelanas odontológicas, através da técnica de dilatometria e verificar a possível compatibilidade térmica dos pares metal/cerâmica. Simulando a entrada de um novo produto no mercado, desenvolveu-se uma liga Ni-Cr experimental denominada SR, que foi comparada a uma liga comercial de Ni-Cr bastante utilizada em restaurações metalocerâmicas. A partir da análise das curvas de expansão térmica, foi possível verificar a compatibilidade dos pares metal/cerâmica quanto à dilatação térmica, segundo os conceitos preconizados por YAMAMOTO7 (1985. Sob este aspecto, a liga experimental apresentou valores que a incluem como mais uma opção na família de ligas Ni-Cr para utilização em restaurações metalocerâmicas. Os resultados obtidos indicam que o equipamento e a metodologia utilizados são adequados para análise comparativa da compatibilidade térmica entre ligas metálicas Ni-Cr e porcelanas odontológicas.

  4. A liga republicana das mulheres portuguesas e a enfermagem no século xx: leituras na imprensa feminista La “Liga Republicana das Mulheres Portuguesas” y la enfermería in el siglo XX: lecturas en los periódicos feministas The “Liga Republicana das Mulheres Portuguesas” and nursing profession in the XXth century: readings in the feminist press

    Directory of Open Access Journals (Sweden)

    Ana Maria Barros Pires


    Full Text Available As representações que a sociedade associa à profissão de enfermagem e à enfermeira, muitas vezes contraditórias, persistem no imaginário individual e coletivo e pouco têm a ver com a evolução verificada no âmbito do exercício profissional, do ensino e da academia. As imagens associadas à enfermeira e à enfermagem inscrevem-se na memória dum passado mais ou menos longínquo e poderão ter uma justificação histórica, social e cultural. Desvendar do modo como as representações sociais associadas à enfermeira e à enfermagem se constituíram no passado poderá permitir-nos recriar, no presente, o percurso da nossa identidade profissional e compreender como, enquanto grupo social, produzimos, consumimos, divulgamos e assumimos imagens que definem essa própria identidade. Propomo-nos neste artigo dar a conhecer como a Liga Republicana das Mulheres Portuguesas (LRMP, no início do século XX, criou uma imagem positiva da enfermagem, desenvolvendo um discurso elogioso da profissão captando o interesse das mulheres para uma “profissão digna” que lhes possibilitaria a independência económica em caso de abandono ou viuvez. Utilizaremos um conjunto de artigos publicados na imprensa oficial da Liga: A Mulher e A Criança e A Madrugada dado que a imprensa foi uma importante forma de divulgação e doutrinação das ideias feministas.Las representaciones que la sociedad asocia con la profesión de enfermería y a la enfermera, a menudo contradictorias, persisten en el imaginario individual y colectivo y tienen poco que ver con la evolución en el campo profesional, la educación y la academia. Las imágenes asociadas con la enfermera y la enfermería están registradas en la memoria de un pasado más o menos lejano y pueden tener una justificación histórica, cultural y social. Descubrir cómo las representaciones asociadas con la enfermería y la enfermera se constituyeron nos permitirá recrear el curso de nuestra identidad

  5. Spreading of aqueous solutions of trisiloxanes and conventional surfactants over PTFE AF coated silicone wafers. (United States)

    Ivanova, Natalia; Starov, Victor; Johnson, Daniel; Hilal, Nidal; Rubio, Ramon


    Kinetics of spreading of aqueous trisiloxane surfactant T(n) (with n = 4, 6, and 8 ethoxy groups) solutions and conventional aqueous surfactant solutions (Tween 20, C12E4, SDS) over silicon wafers coated with PTFE AF is experimentally investigated. It has been found that trisiloxane solutions spread on highly hydrophobic PTFE AF coated silicone wafers; however, they do not show superspreading behavior on these highly hydrophobic substrates. Solutions of conventional nonionic surfactants investigated show kinetics of spreading similar to trisiloxanes. Three regimes of spreading have been identified (i) complete non-wetting during the spreading process at low concentrations, (ii) a transition from initial nonwetting to partial wetting at the end of the spreading process at intermediate concentrations, and (iii) partial wetting both at the beginning and the end of the spreading process at higher concentrations. Transition from the first regime (i) to the second regime (ii) takes place at the critical aggregation concentration (CAC) or critical micelle concentration (CMC), transition from regime (ii) to regime (iii) happens at the critical wetting concentration (CWC). In the case of regime (i) the spreading of nonionic surfactants solutions investigated on PTFE AF coated silicone wafers is slow and follows a theoretically predicted law (Starov; et al. J. Colloid Interface Sci. 2000, 227 (1), 185). In the case of regimes (ii) and (iii), the spreading of the nonionic surfactant solutions investigated proceeds in two stages: the fast short first stage, which is followed by a much slower second stage. It is shown that the slow stage develops according to a previously described theoretical model. According to this theory the surfactant molecules adsorb in front of the moving three-phase contact line (autophilic phenomenon), which results in a partial hydrophilisation of an initially hydrophobic substrate and a spreading as a consequence. We assume that the first stage of

  6. The Forming Process Researched in Sandblasting Separation of Masked Silicon Wafers

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    V. V. Zhukov


    Full Text Available The object of study is a semiconductor silicon disc-crystal currently used in the design of semiconductor diodes. The disc-crystal is manufactured by the sandblasting separation of a premasked silicon wafer into individual elements. The crystal has frustum-of-a-cone shape with its top diameter determined by a protective masking disc diameter and the bottom one defined by the features of the forming process. The apex angle of the cone 2α or a half-angle α between the lateral surface of the cone and the normal drawn to its base is used as a reference value.The work has studied the influence a thickness of the separated wafer and a width of the gap between the masked discs on the crystal shape. The masking cover is a set of square protective elements (3x3 mm, spaced at 0.6; 0.7; 0.8 and 0.9 mm. The mask material is a self-adhesive PVC-film with thickness of 200 microns. Pilot-plant semi-automatic sandblasting equipment was used to for separation.After processing of results (the angle 2α at the top of the cone the following conclusions have been made:- with increasing thickness of the silicon wafers the gap between the protective discs of mask must be increased;- in case a range of the minimum gaps between the protective discs is within 0.35 - 1.20 mm the half-angle α, which defines the shape of the cut surface, can be considered to be constant and equal to 12º ... 14º.

  7. Direct and simultaneous determination of Co and Cu on a silicon wafer using a chemiluminescence system. (United States)

    Sung, Y I; Jang, J W; Lim, H B


    In this work, we developed a drop-type chemiluminescence (CL) system with a partial least squares (PLS) calibration in which the coaxial optical fiber sensing head was developed for sampling and detection to determine Cu(2+) and Co(2+) on a silicon wafer directly. The use of time-resolved signal generation and PLS calibration in addition to CL allowed us to determine the metal ions simultaneously and selectively, based on the kinetic difference of Cu and Co ions in the luminol-H(2)O(2) system. Two component mixtures with a set of 15 wafer fragments were orthogonally calibrated. After prediction test, the method was applied to an intentionally contaminated silicon wafer and validated by inductively coupled plasma-mass spectrometer (ICP-MS) measurement with a HF-HNO(3) scanning solution. The average concentrations of Cu(2+) and Co(2+) of 3.45 (±0.95) × 10(13) and 2.30 (±1.18) × 10(11) atoms per cm(2), respectively, were obtained, which were very close to the ICP-MS results of 3.70 × 10(13) for Cu(2+) and 2.46 × 10(11) atoms per cm(2) for Co(2+). In conclusion, this drop mode CL showed almost more than 10 times better reproducibility than the typical batch mode for the profile measurement. Moreover, the adoption of PLS calibration added the function of selectivity for the simultaneous determination to this CL system, in addition to the direct mapping capability for the solid surface analysis.

  8. Integrated optical MEMS using through-wafer vias and bump-bonding.

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, Frederick Bossert; Frederick, Scott K.


    This LDRD began as a three year program to integrate through-wafer vias, micro-mirrors and control electronics with high-voltage capability to yield a 64 by 64 array of individually controllable micro-mirrors on 125 or 250 micron pitch with piston, tip and tilt movement. The effort was a mix of R&D and application. Care was taken to create SUMMiT{trademark} (Sandia's ultraplanar, multilevel MEMS technology) compatible via and mirror processes, and the ultimate goal was to mate this MEMS fabrication product to a complementary metal-oxide semiconductor (CMOS) electronics substrate. Significant progress was made on the via and mirror fabrication and design, the attach process development as well as the electronics high voltage (30 volt) and control designs. After approximately 22 months, the program was ready to proceed with fabrication and integration of the electronics, final mirror array, and through wafer vias to create a high resolution OMEMS array with individual mirror electronic control. At this point, however, mission alignment and budget constraints reduced the last year program funding and redirected the program to help support the through-silicon via work in the Hyper-Temporal Sensors (HTS) Grand Challenge (GC) LDRD. Several months of investigation and discussion with the HTS team resulted in a revised plan for the remaining 10 months of the program. We planned to build a capability in finer-pitched via fabrication on thinned substrates along with metallization schemes and bonding techniques for very large arrays of high density interconnects (up to 2000 x 2000 vias). Through this program, Sandia was able to build capability in several different conductive through wafer via processes using internal and external resources, MEMS mirror design and fabrication, various bonding techniques for arrayed substrates, and arrayed electronics control design with high voltage capability.

  9. Wafer-level fabrication of multi-element glass lenses: lens doublet with improved optical performances. (United States)

    Albero, Jorge; Perrin, Stéphane; Passilly, Nicolas; Krauter, Johann; Gauthier-Manuel, Ludovic; Froehly, Luc; Lullin, Justine; Bargiel, Sylwester; Osten, Wolfgang; Gorecki, Christophe


    This Letter reports on the fabrication of glass lens doublets arranged in arrays and realized at wafer level by means of micro-fabrication. The technique is based on the accurate vertical assembly of separately fabricated glass lens arrays. Since each one of these arrays is obtained by glass melting in silicon cavities, silicon is employed as a spacer in order to build a well-aligned and robust optical module. It is shown that optical performance achieved by the lens doublet is better than for a single lens of equivalent numerical aperture, thanks to lower optical aberrations. The technique has good potential to match the optical requirements of miniature imaging systems.

  10. Effect of the Tilt Angle on Antimony in Silicon Implanted Wafers


    Claudio, G; Kirkby, K.J.; Bersani, M.; Low, R.; Sealy, B. J.; Gwilliam, R


    A dose of 5.0x10(14) antimony (Sb+) ions cm(-2) was implanted into silicon wafers at an energy of 70 keV, at different tilt angles (0degrees, 15degrees, 30degrees, 45degrees, and 60degrees). One set of samples was preamorphized with 160 keV germanium (Ge+) ions with a dose of 1x10(15) cm(-2). The second set consisted of implants into single crystal silicon. After implantation the samples were annealed at 700 degreesC for 30 s in a pure nitrogen ambient. Secondary ion mass spectroscopy was per...

  11. Gated Silicon Drift Detector Fabricated from a Low-Cost Silicon Wafer


    Hideharu Matsuura; Shungo Sakurai; Yuya Oda; Shinya Fukushima; Shohei Ishikawa; Akinobu Takeshita; Atsuki Hidaka


    Inexpensive high-resolution silicon (Si) X-ray detectors are required for on-site surveys of traces of hazardous elements in food and soil by measuring the energies and counts of X-ray fluorescence photons radially emitted from these elements. Gated silicon drift detectors (GSDDs) are much cheaper to fabricate than commercial silicon drift detectors (SDDs). However, previous GSDDs were fabricated from \\(10\\)-k\\(\\Omega \\cdot\\)cm Si wafers, which are more expensive than \\(2\\)-k\\(\\Omega \\cdot\\)c...

  12. Production planning and control for semiconductor wafer fabrication facilities modeling, analysis, and systems

    CERN Document Server

    Mönch, Lars; Mason, Scott J


    Over the last fifty-plus years, the increased complexity and speed of integrated circuits have radically changed our world. Today, semiconductor manufacturing is perhaps the most important segment of the global manufacturing sector. As the semiconductor industry has become more competitive, improving planning and control has become a key factor for business success. This book is devoted to production planning and control problems in semiconductor wafer fabrication facilities. It is the first book that takes a comprehensive look at the role of modeling, analysis, and related information systems

  13. A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers


    Zhenyu Zhang; Bo Wang; Ping Zhou; Renke Kang; Bi Zhang; Dongming Guo


    A novel approach of chemical mechanical polishing (CMP) is developed for cadmium zinc telluride (CdZnTe or CZT) wafers. The approach uses environment-friendly slurry that consists of mainly silica, hydrogen peroxide, and citric acid. This is different from the previously reported slurries that are usually composed of strong acid, alkali, and bromine methanol, and are detrimental to the environment and operators. Surface roughness 0.5?nm and 4.7?nm are achieved for Ra and peak-to-valley (PV) v...

  14. Wafer-Level Hybrid Integration of Complex Micro-Optical Modules

    Directory of Open Access Journals (Sweden)

    Peter Dannberg


    Full Text Available A series of technological steps concentrating around photolithography and UV polymer on glass replication in a mask-aligner that allow for the cost-effective generation of rather complex micro-optical systems on the wafer level are discussed. In this approach, optical functional surfaces are aligned to each other and stacked on top of each other at a desired axial distance. They can consist of lenses, achromatic doublets, regular or chirped lens arrays, diffractive elements, apertures, filter structures, reflecting layers, polarizers, etc. The suitability of the separated modules in certain imaging and non-imaging applications will be shown.

  15. Optimal mask characterization by Surrogate Wafer Print (SWaP) method (United States)

    Kimmel, Kurt R.; Hoellein, Ingo; Peters, Jan Hendrick; Ackmann, Paul; Connolly, Brid; West, Craig


    Traditionally, definition of mask specifications is done completely by the mask user, while characterization of the mask relative to the specifications is done completely by the mask maker. As the challenges of low-k1 imaging continue to grow in scope of designs and in absolute complexity, the inevitable partnership between wafer lithographers and mask makers has strengthened as well. This is reflected in the jointly owned mask facilities and device manufacturers' continued maintenance of fully captive mask shops which foster the closer mask-litho relationships. However, while some device manufacturers have leveraged this to optimize mask specifications before the mask is built and, therefore, improve mask yield and cost, the opportunity for post-fabrication partnering on mask characterization is more apparent and compelling. The Advanced Mask Technology Center (AMTC) has been investigating the concept of assessing how a mask images, rather than the mask's physical attributes, as a technically superior and lower-cost method to characterize a mask. The idea of printing a mask under its intended imaging conditions, then characterizing the imaged wafer as a surrogate for traditional mask inspections and measurements represents the ultimate method to characterize a mask's performance, which is most meaningful to the user. Surrogate wafer print (SWaP) is already done as part of leading-edge wafer fab mask qualification to validate defect and dimensional performance. In the past, the prospect of executing this concept has generally been summarily discarded as technically untenable and logistically intractable. The AMTC published a paper at BACUS 2007 successfully demonstrating the performance of SWaP for the characterization of defects as an alternative to traditional mask inspection [1]. It showed that this concept is not only feasible, but, in some cases, desirable. This paper expands on last year's work at AMTC to assess the full implementation of SWaP as an

  16. Worker exposure to methanol vapors during cleaning of semiconductor wafers in a manufacturing setting. (United States)

    Gaffney, Shannon; Moody, Emily; McKinley, Meg; Knutsen, Jeffrey; Madl, Amy; Paustenbach, Dennis


    An exposure simulation was conducted to characterize methanol exposure of workers who cleaned wafers in quality control departments within the semiconductor industry. Short-term (15 min) and long-term (2-4 hr) personal and area samples (at distances of 1 m and 3-6 m from the source) were collected during the 2-day simulation. On the first day, 45 mL of methanol were used per hour by a single worker washing wafers in a 102 m(3) room with a ventilation rate of about 10 air changes per hour (ACH). Virtually all methanol volatilized. To assess exposures under conditions associated with higher productivity, on the second day, two workers cleaned wafers simultaneously, together using methanol at over twice the rate of the first day (95 mL/hr). On this day, the ventilation rate was halved (5 ACH). Personal concentrations on the first day averaged 60 ppm (SD = 46 ppm) and ranged from 10-140 ppm. On the second day, personal concentrations for both workers averaged 118 ppm (SD = 50 ppm; range: 64-270 ppm). Area concentrations measured on the first day at 1 m from the source and throughout the balance of the room averaged 29 ppm (SD = 19 ppm; range: 4-83 ppm) and 18 ppm (SD = 12 ppm; range: 3-42 ppm), respectively. As expected, area concentrations measured on the second day were higher than the first and averaged 73 ppm (SD = 25 ppm; range: 27-140 ppm) at 1 meter and 48 ppm (SD = 13 ppm; range: 21-67 ppm) throughout the balance of the room. The results of this simulation suggest that the use of methanol to clean semiconductor wafers without the use of local exhaust ventilation and with relatively low room ventilation rates is unlikely to result in worker exposures exceeding the current ACGIH(R) threshold limit value of 200 ppm. This study also confirmed prior studies suggesting that when a relatively volatile chemical is located within arm's length (near field), breathing zone concentrations will be about two- to threefold greater than the room concentration when the air

  17. Morphology of oxygen precipitates in silicon wafers pre-treated by rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Kot, D., E-mail:; Kissinger, G.; Schubert, M. A. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Sattler, A. [Siltronic AG, Hanns-Seidel-Platz 4, 81737 München (Germany)


    The morphology of oxygen precipitates in Czochralski silicon wafers pre-treated by rapid thermal annealing (RTA) and subjected to a heat treatment in the temperature range between 800 °C and 1000 °C was investigated by scanning transmission electron microscopy. The samples were pre-treated by RTA in order to establish a defined supersaturation of vacancies. It was found that in such vacancy-rich samples subjected to an annealing at 800 °C three dimensional dendrites are formed. Until now, it was known that during annealing at 800 °C plate-like oxygen precipitates are formed.

  18. 2-dimensional ion velocity distributions measured by laser-induced fluorescence above a radio-frequency biased silicon wafer

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Nathaniel B.; Gekelman, Walter; Pribyl, Patrick [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); Zhang, Yiting; Kushner, Mark J. [Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122 (United States)


    The dynamics of ions traversing sheaths in low temperature plasmas are important to the formation of the ion energy distribution incident onto surfaces during microelectronics fabrication. Ion dynamics have been measured using laser-induced fluorescence (LIF) in the sheath above a 30 cm diameter, 2.2 MHz-biased silicon wafer in a commercial inductively coupled plasma processing reactor. The velocity distribution of argon ions was measured at thousands of positions above and radially along the surface of the wafer by utilizing a planar laser sheet from a pulsed, tunable dye laser. Velocities were measured both parallel and perpendicular to the wafer over an energy range of 0.4–600 eV. The resulting fluorescence was recorded using a fast CCD camera, which provided resolution of 0.4 mm in space and 30 ns in time. Data were taken at eight different phases during the 2.2 MHz cycle. The ion velocity distributions (IVDs) in the sheath were found to be spatially non-uniform near the edge of the wafer and phase-dependent as a function of height. Several cm above the wafer the IVD is Maxwellian and independent of phase. Experimental results were compared with simulations. The experimental time-averaged ion energy distribution function as a function of height compare favorably with results from the computer model.

  19. Bijau, pykstu ir gaila: psichikos liga sergančiuosius stigmatizuojančių emocijų palyginimas JAV ir Lietuvos psichikos sveikatos specialistų grupėse


    Markšaitytė, Rasa; Pranckevičienė, Aistė; Matulaitienė, Kristina; Endriulaitienė, Auksė; Hof, David D; Tillman, Douglas R


    Įvadas. Paprastai iš psichikos sveikatos priežiūros specialistų tikimasi, teigiamesnio požiūrio į psichikos liga sergančius asmenis, o didėjant profesinėms žinioms apie psichikos ligas bei kaupaintis darbo patirčiai tarsi natūraliai turėtų mažėti ir šiomis ligomis sergančiųjų baimė, gailestis bei pyktis jiems. Šiuo tyrimu siekiama palyginti stigmatizuojančių emocijų dinamiką priklausomai nuo psichologijos ir socialinio darbo studentų bei specialistų profesinės patirties Lietuvoje bei JAV. Met...



    Aline Maria dos Santos Teixeira; João Alves Sampaio; Luiz Carlos Bertolino; Eros Freire Cardoso; Lucas de Campos Paula Borges


    A escória Fe-Cr baixo carbono, é um dos principais resíduos advindos do processo metalúrgico para obtenção de liga de Fe-Cr. Este resíduo não possui aplicação e encontra-se acumulado em pátios, conforme regulamentação de órgãos ambientais. Este trabalho teve por finalidade caracterizar, sob os aspectos químicos e físicos, a escória Fe-Cr baixo carbono, pertencente à Companhia de Ferro e Ligas da Bahia S/A, FERBASA. Também foram realizados ensaios de concentração gravítica com a finalidade de ...

  1. Influência do teor de Mo na microestrutura de ligas Fe-9Cr-xMo Effect of the content of molybdenum in the microstructure of Fe-9Cr-xMo alloy

    Directory of Open Access Journals (Sweden)

    Rodrigo Freitas Guimarães


    Full Text Available Aços Cr-Mo são usados na indústria do petróleo em aplicações com óleos crus ricos em compostos sulfurosos. Aços comerciais como 2.5Cr1Mo ou 9Cr1Mo têm se mostrado ineficientes em consequência de altos índices de corrosão naftênica. Uma estratégia para resolver este problema é o aumento do teor de molibdênio destes aços. Neste trabalho foi estudado o efeito do aumento do teor de molibdênio na microestrutura de ligas Fe-9Cr-xMo, solubilizadas e soldadas. Foram levantados os diagramas de fases com auxílio de um programa comercial para verificar as possíveis fases a serem formadas e identificar os problemas de soldagem. A microestrutura das ligas solubilizadas foi analisada por microscopia óptica e EBSD, além da medição da dureza. Foram realizadas soldagens autógenas para verificar o efeito do aporte térmico na microestrutura e na dureza das ligas. O aumento do teor de molibdênio resultou no aumento da dureza das ligas. A análise microestrutural das ligas soldadas apresentou uma particularidade para a liga com menor teor de molibdênio, a presença de martensita. Já as ligas com maior teor de molibdênio apresentaram uma microestrutura completamente ferrítica. A formação de martensita pode ser um problema na solda da liga com menor teor de molibdênio, uma vez que a mesma pode causar perdas nas propriedades mecânicas comprometendo sua aplicação.Cr-Mo steels are used in the petroleum industry in applications with crude oils rich in sulfur compounds. 2.5Cr1Mo or 9Cr1Mo do not resist to operating conditions when in contact with crude oils. The increasing of molybdenum content can improve the corrosion resistance of these alloys. This paper studied the effect of increased concentration of molybdenum in the microstructure of Fe-9Cr-xMo alloys, annealed and welded. Phase diagrams were built with the aid of commercial program to check the possible phases to be formed and to identify the problems of welding. Analyses were

  2. El litigio entre las Brigadas Femeninas y la Liga Defensora de la Libertad Religiosa, durante la persecución callista a los cristeros, 1925-1929 (La masonería blanca

    Directory of Open Access Journals (Sweden)

    Héctor Díaz Zermeño


    Full Text Available Se muestra las diferencias y coincidencias entre las Brigadas Femeninas Cristeras y la Liga de los hombres que pretendían el liderazgo total en la lucha contra el gobierno mexicano anti cristero. El fin de esta triste historia fue el triunfo de los segundos en connivencia con la jerarquía católica, el gobierno y la intromisión norteamericana.

  3. ASIC Wafer Test System for the ATLAS Semiconductor Tracker Front-End Chip

    Energy Technology Data Exchange (ETDEWEB)

    Anghinolfi, F.; Bialas, W.; Busek, N.; Ciocio, A.; Cosgrove, D.; Fadeyev, V.; Flacco, C.; Gilchriese, M.; Grillo, A.A.; Haber, C.; Kaplon, J.; Lacasta, C.; Murray, W.; Niggli, H.; Pritchard, T.; Rosenbaum, F.; Spieler, H.; Stezelberger, T.; Vu, C.; Wilder, M.; Yaver, H.; Zetti, F.


    An ASIC wafer test system has been developed to provide comprehensive production screening of the ATLAS Semiconductor Tracker front-end chip (ABCD3T). The ABCD3T[1] features a 128-channel analog front-end, a digital pipeline, and communication circuitry, clocked at 40 MHz, which is the bunch crossing frequency at the LHC (Large Hadron Collider). The tester measures values and tolerance ranges of all critical IC parameters, including DC parameters, electronic noise, time resolution, clock levels and clock timing. The tester is controlled by an FPGA (ORCA3T) programmed to issue the input commands to the IC and to interpret the output data. This allows the high-speed wafer-level IC testing necessary to meet the production schedule. To characterize signal amplitudes and phase margins, the tester utilizes pin-driver, delay, and DAC chips, which control the amplitudes and delays of signals sent to the IC under test. Output signals from the IC under test go through window comparator chips to measure their levels. A probe card has been designed specifically to reduce pick-up noise that can affect the measurements. The system can operate at frequencies up to 100 MHz to study the speed limits of the digital circuitry before and after radiation damage. Testing requirements and design solutions are presented.

  4. Study on chemical mechanical polishing of silicon wafer with megasonic vibration assisted. (United States)

    Zhai, Ke; He, Qing; Li, Liang; Ren, Yi


    Chemical mechanical polishing (CMP) is the primary method to realize the global planarization of silicon wafer. In order to improve this process, a novel method which combined megasonic vibration to assist chemical mechanical polishing (MA-CMP) is developed in this paper. A matching layer structure of polishing head was calculated and designed. Silicon wafers are polished by megasonic assisted chemical mechanical polishing and traditional chemical mechanical polishing respectively, both coarse polishing and precision polishing experiments were carried out. With the use of megasonic vibration, the surface roughness values Ra reduced from 22.260nm to 17.835nm in coarse polishing, and the material removal rate increased by approximately 15-25% for megasonic assisted chemical mechanical polishing relative to traditional chemical mechanical polishing. Average Surface roughness values Ra reduced from 0.509nm to 0.387nm in precision polishing. The results show that megasonic assisted chemical mechanical polishing is a feasible method to improve polishing efficiency and surface quality. The material removal and finishing mechanisms of megasonic vibration assisted polishing are investigated too. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Preparation of immobilized glucose oxidase wafer enzyme on calcium-bentonite modified by surfactant (United States)

    Widi, R. K.; Trisulo, D. C.; Budhyantoro, A.; Chrisnasari, R.


    Wafer glucose oxidase (GOx) enzymes was produced by addition of PAH (Poly-Allyamine Hydrochloride) polymer into immobilized GOx enzyme on modified-Tetramethylammonium Hydroxide (TMAH) 5%-calsium-bentonite. The use of surfactant molecul (TMAH) is to modify the surface properties and pore size distribution of the Ca-bentonite. These properties are very important to ensure GOx molecules can be bound on the Ca-bentonit surface to be immobilized. The addition of the polymer (PAH) is expected to lead the substrates to be adsorbed onto the enzyme. In this study, wafer enzymes were made in various concentration ratio (Ca-bentonite : PAH) which are 1:0, 1:1, 1:2 and 1:3. The effect of PAH (Poly-Allyamine Hydrochloride) polymer added with various ratios of concentrations can be shown from the capacitance value on LCR meter and enzyme activity using DNS method. The addition of the polymer (PAH) showed effect on the activity of GOx, it can be shown from the decreasing of capacitance value by increasing of PAH concentration.

  6. Digital Platform for Wafer-Level MEMS Testing and Characterization Using Electrical Response

    Directory of Open Access Journals (Sweden)

    Nuno Brito


    Full Text Available The uniqueness of microelectromechanical system (MEMS devices, with their multiphysics characteristics, presents some limitations to the borrowed test methods from traditional integrated circuits (IC manufacturing. Although some improvements have been performed, this specific area still lags behind when compared to the design and manufacturing competencies developed over the last decades by the IC industry. A complete digital solution for fast testing and characterization of inertial sensors with built-in actuation mechanisms is presented in this paper, with a fast, full-wafer test as a leading ambition. The full electrical approach and flexibility of modern hardware design technologies allow a fast adaptation for other physical domains with minimum effort. The digital system encloses a processor and the tailored signal acquisition, processing, control, and actuation hardware control modules, capable of the structure position and response analysis when subjected to controlled actuation signals in real time. The hardware performance, together with the simplicity of the sequential programming on a processor, results in a flexible and powerful tool to evaluate the newest and fastest control algorithms. The system enables measurement of resonant frequency (Fr, quality factor (Q, and pull-in voltage (Vpi within 1.5 s with repeatability better than 5 ppt (parts per thousand. A full-wafer with 420 devices under test (DUTs has been evaluated detecting the faulty devices and providing important design specification feedback to the designers.

  7. A Wafer Level Vacuum Encapsulated Capacitive Accelerometer Fabricated in an Unmodified Commercial MEMS Process

    Directory of Open Access Journals (Sweden)

    Adel Merdassi


    Full Text Available We present the design and fabrication of a single axis low noise accelerometer in an unmodified commercial MicroElectroMechanical Systems (MEMS process. The new microfabrication process, MEMS Integrated Design for Inertial Sensors (MIDIS, introduced by Teledyne DALSA Inc. allows wafer level vacuum encapsulation at 10 milliTorr which provides a high Quality factor and reduces noise interference on the MEMS sensor devices. The MIDIS process is based on high aspect ratio bulk micromachining of single-crystal silicon layer that is vacuum encapsulated between two other silicon handle wafers. The process includes sealed Through Silicon Vias (TSVs for compact design and flip-chip integration with signal processing circuits. The proposed accelerometer design is sensitive to single-axis in-plane acceleration and uses a differential capacitance measurement. Over ±1 g measurement range, the measured sensitivity was 1fF/g. The accelerometer system was designed to provide a detection resolution of 33 milli-g over the operational range of ±100 g.

  8. A wafer level vacuum encapsulated capacitive accelerometer fabricated in an unmodified commercial MEMS process. (United States)

    Merdassi, Adel; Yang, Peng; Chodavarapu, Vamsy P


    We present the design and fabrication of a single axis low noise accelerometer in an unmodified commercial MicroElectroMechanical Systems (MEMS) process. The new microfabrication process, MEMS Integrated Design for Inertial Sensors (MIDIS), introduced by Teledyne DALSA Inc. allows wafer level vacuum encapsulation at 10 milliTorr which provides a high Quality factor and reduces noise interference on the MEMS sensor devices. The MIDIS process is based on high aspect ratio bulk micromachining of single-crystal silicon layer that is vacuum encapsulated between two other silicon handle wafers. The process includes sealed Through Silicon Vias (TSVs) for compact design and flip-chip integration with signal processing circuits. The proposed accelerometer design is sensitive to single-axis in-plane acceleration and uses a differential capacitance measurement. Over ±1 g measurement range, the measured sensitivity was 1 fF/g. The accelerometer system was designed to provide a detection resolution of 33 milli-g over the operational range of ±100 g.

  9. Microscopic Distributions of Defect Luminescence From Subgrain Boundaries in Multicrystalline Silicon Wafers

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Hieu T.; Jensen, Mallory A.; Li, Li; Samundsett, Christian; Sio, Hang C.; Lai, Barry; Buonassisi, Tonio; Macdonald, Daniel


    We investigate the microscopic distributions of sub-band-gap luminescence emission (the so-called D-lines D1/D2/D3/D4) and the band-to-band luminescence intensity, near recombination-active sub-grain boundaries in multicrystalline silicon wafers for solar cells. We find that the sub-band-gap luminescence from decorating defects/impurities (D1/D2) and from intrinsic dislocations (D3/D4) have distinctly different spatial distributions, and are asymmetric across the sub-grain boundaries. The presence of D1/D2 is correlated with a strong reduction in the band-to-band luminescence, indicating a higher recombination activity. In contrast, D3/D4 emissions are not strongly correlated with the band-to-band intensity. Based on spatially-resolved, synchrotron-based micro-X-ray fluorescence measurements of metal impurities, we confirm that high densities of metal impurities are present at locations with strong D1/D2 emission but low D3/D4 emission. Finally, we show that the observed asymmetry of the sub-band-gap luminescence across the sub-grain boundaries is due to their inclination below the wafer surface. Based on the luminescence asymmetries, the sub-grain boundaries are shown to share a common inclination locally, rather than be orientated randomly.

  10. A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers (United States)

    Zhang, Zhenyu; Wang, Bo; Zhou, Ping; Kang, Renke; Zhang, Bi; Guo, Dongming


    A novel approach of chemical mechanical polishing (CMP) is developed for cadmium zinc telluride (CdZnTe or CZT) wafers. The approach uses environment-friendly slurry that consists of mainly silica, hydrogen peroxide, and citric acid. This is different from the previously reported slurries that are usually composed of strong acid, alkali, and bromine methanol, and are detrimental to the environment and operators. Surface roughness 0.5 nm and 4.7 nm are achieved for Ra and peak-to-valley (PV) values respectively in a measurement area of 70 × 50 μm2, using the developed novel approach. Fundamental polishing mechanisms are also investigated in terms of X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Hydrogen peroxide dominates the passivating process during the CMP of CZT wafers, indicating by the lowest passivation current density among silica, citric acid and hydrogen peroxide solution. Chemical reaction equations are proposed during CMP according to the XPS and electrochemical measurements. PMID:27225310

  11. A novel approach of chemical mechanical polishing for cadmium zinc telluride wafers. (United States)

    Zhang, Zhenyu; Wang, Bo; Zhou, Ping; Kang, Renke; Zhang, Bi; Guo, Dongming


    A novel approach of chemical mechanical polishing (CMP) is developed for cadmium zinc telluride (CdZnTe or CZT) wafers. The approach uses environment-friendly slurry that consists of mainly silica, hydrogen peroxide, and citric acid. This is different from the previously reported slurries that are usually composed of strong acid, alkali, and bromine methanol, and are detrimental to the environment and operators. Surface roughness 0.5 nm and 4.7 nm are achieved for Ra and peak-to-valley (PV) values respectively in a measurement area of 70 × 50 μm(2), using the developed novel approach. Fundamental polishing mechanisms are also investigated in terms of X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. Hydrogen peroxide dominates the passivating process during the CMP of CZT wafers, indicating by the lowest passivation current density among silica, citric acid and hydrogen peroxide solution. Chemical reaction equations are proposed during CMP according to the XPS and electrochemical measurements.

  12. Aerosol-assisted extraction of silicon nanoparticles from wafer slicing waste for lithium ion batteries. (United States)

    Jang, Hee Dong; Kim, Hyekyoung; Chang, Hankwon; Kim, Jiwoong; Roh, Kee Min; Choi, Ji-Hyuk; Cho, Bong-Gyoo; Park, Eunjun; Kim, Hansu; Luo, Jiayan; Huang, Jiaxing


    A large amount of silicon debris particles are generated during the slicing of silicon ingots into thin wafers for the fabrication of integrated-circuit chips and solar cells. This results in a significant loss of valuable materials at about 40% of the mass of ingots. In addition, a hazardous silicon sludge waste is produced containing largely debris of silicon, and silicon carbide, which is a common cutting material on the slicing saw. Efforts in material recovery from the sludge and recycling have been largely directed towards converting silicon or silicon carbide into other chemicals. Here, we report an aerosol-assisted method to extract silicon nanoparticles from such sludge wastes and their use in lithium ion battery applications. Using an ultrasonic spray-drying method, silicon nanoparticles can be directly recovered from the mixture with high efficiency and high purity for making lithium ion battery anode. The work here demonstrated a relatively low cost approach to turn wafer slicing wastes into much higher value-added materials for energy applications, which also helps to increase the sustainability of semiconductor material and device manufacturing.

  13. Avaliação de Revestimentos de Liga de Níquel 625 Depositados pelo Processo Eletroescória

    Directory of Open Access Journals (Sweden)

    Soraia Simões Sandes

    Full Text Available Resumo A aplicação de revestimentos de ligas de níquel é comumente realizada na indústria de petróleo e gás para aumento da vida de equipamentos em ambientes agressivos, dado que este procedimento melhora a resistência à corrosão, sem um aumento significativo do custo de produção quando comparado com equipamentos maciços fabricados com outras ligas. Normalmente, as juntas são soldadas pelos processos de eletrodos revestidos, MIG/MAG ou TIG. Neste aspecto, o processo eletroescória realiza deposições com elevada energia de soldagem e baixa diluição, podendo ser uma opção interessante, uma vez que proporciona uma elevada produtividade, permitindo a soldagem com aplicação de apenas uma camada. O presente trabalho avalia propriedades mecânicas, microestruturais e de corrosão de revestimentos de liga de níquel 625 depositada em aço carbono ASTM A516 Grau 70 pelo processo eletroescória, tanto na condição como soldado quanto tratado termicamente. A deposição foi realizada com uma e duas camadas sobre chapas de dimensão 50x400x400 mm, na posição plana e energia de soldagem média de 11,7 kJ/mm. Após a soldagem realizou-se tratamento térmico a 620°C por 10 horas, sendo esta condição comparada ao estado de como soldado. Os ensaios de dobramento não indicaram evidências de defeitos. A avaliação microestrutural realizada por microscopia ótica (MO, eletrônica de varredura (MEV e eletrônica de transmissão (MET mostrou uma microestrutura austenítica para o depósito com pequena fração volumétrica de fases secundárias e o tratamento térmico de alívio de tensões não promoveu mudanças significativas nas propriedades. Na região de grãos grosseiros da zona termicamente afetada (RGGZTA foi observada a ocorrência de ferrita pró-eutetóide, perlita e bainita para o depósito com 1 camada e basicamente ferrita e perlita refinadas para o deposito com 2 passes devido às baixas taxas de resfriamento

  14. Sputtered Encapsulation as Wafer Level Packaging for Isolatable MEMS Devices: A Technique Demonstrated on a Capacitive Accelerometer. (United States)

    Hamzah, Azrul Azlan; Yunas, Jumril; Majlis, Burhanuddin Yeop; Ahmad, Ibrahim


    This paper discusses sputtered silicon encapsulation as a wafer level packaging approach for isolatable MEMS devices. Devices such as accelerometers, RF switches, inductors, and filters that do not require interaction with the surroundings to function, could thus be fully encapsulated at the wafer level after fabrication. A MEMSTech 50g capacitive accelerometer was used to demonstrate a sputtered encapsulation technique. Encapsulation with a very uniform surface profile was achieved using spin-on glass (SOG) as a sacrificial layer, SU-8 as base layer, RF sputtered silicon as main structural layer, eutectic gold-silicon as seal layer, and liquid crystal polymer (LCP) as outer encapsulant layer. SEM inspection and capacitance test indicated that the movable elements were released after encapsulation. Nanoindentation test confirmed that the encapsulated device is sufficiently robust to withstand a transfer molding process. Thus, an encapsulation technique that is robust, CMOS compatible, and economical has been successfully developed for packaging isolatable MEMS devices at the wafer level.

  15. Size effect in self-propagating exothermic reaction of Al/Ni multilayer block on a Si wafer (United States)

    Namazu, Takahiro; Ito, Shun; Kanetsuki, Shunsuke; Miyake, Shugo


    In this paper, the threshold size of sputtered Al/Ni multilayer blocks required for inducing a self-propagating exothermic reaction on a Si wafer is described. An Al/Ni multilayer film with a bilayer thickness of 100 nm is deposited on a Si wafer, and then micronsized Al/Ni multilayer blocks from the film are fabricated using a focused ion beam. By inducing small sparks in the vicinity of the blocks, we investigate reactivity. From scanning electron microscopy observations, we confirm that Al/Ni multilayer blocks with high aspect ratios and small widths can react easily. The effect of Al/Ni multilayer block size on reactivity is discussed from the viewpoint of heat conduction from the block to a Si wafer during an exothermic reaction.

  16. Functional Testing and Characterisation of ISFETs on Wafer Level by Means of a Micro-droplet Cell

    Directory of Open Access Journals (Sweden)

    Michael J. Schöning


    Full Text Available A wafer-level functionality testing and characterisation system for ISFETs (ion-sensitive field-effect transistor is realised by means of integration of a specifically designedcapillary electrochemical micro-droplet cell into a commercial wafer prober-station. Thedeveloped system allows the identification and selection of “good” ISFETs at the earlieststage and to avoid expensive bonding, encapsulation and packaging processes for non-functioning ISFETs and thus, to decrease costs, which are wasted for bad dies. Thedeveloped system is also feasible for wafer-level characterisation of ISFETs in terms ofsensitivity, hysteresis and response time. Additionally, the system might be also utilised forwafer-level testing of further electrochemical sensors.

  17. 8 mW fundamental mode output of wafer-fused VCSELs emitting in the 1550-nm band. (United States)

    Caliman, Andrei; Mereuta, Alexandru; Suruceanu, Grigore; Iakovlev, Vladimir; Sirbu, Alexei; Kapon, Eli


    We report record-high fundamental mode output power of 8 mW at 0 °C and 1.5 mW at 100°C achieved with wafer-fused InAlGaAs-InP/AlGaAs-GaAs 1550 nm VCSELs incorporating a re-grown tunnel junction and un-doped AlGaAs/GaAs distributed Bragg reflectors. A broad wavelength tuning range of 15 nm by current variation and wavelength setting in a spectral range of 40 nm on the same VCSEL wafer are demonstrated as well. This performance positions wafer-fused VCSELs as prime candidates for many applications in low power consumption, "green" photonics.

  18. Stabilisation of a thin crystalline Si wafer solar cell using glass substrate; Duenne kristalline Silizium Wafer-Solarzelle mit Glastraeger stabilisiert

    Energy Technology Data Exchange (ETDEWEB)

    Muehlbauer, Maria


    An attempt was made to stabilise ultrathin crystalline silicon wafers (< 100 {mu}m) by a support material (BOROFLOAT33 by Schott Glas). It was found that the total serial resistance results mainly from the specific resistance of the back contact, and that especially the ultrathin solar cells have high recombination in the back. The ultrathin Si wafers also are slightly corrugated, which results in uneven joining of the Si wafer with the glass support. For optimisation, the solar cells of this specific types, with different thicknesses, were modelled in the one-dimensional simulation code PC1D, including all material-specific and electric properties. It was found that a slight reduction of the serial resistance will be enough for a significant improvement of the efficiency of the stabilized solar cell. With this knowledge, selective optimisation of the stabilised solar cells was possible, with the following results: 1. The improved temperature-time profile of the RTP step will improve the solar cell parameters for all Si thicknesses, which is assumed to be the result of better quality of the Al/Si back contact. 2. Thicker aluminium layers improved passivation on the back of solar cells with a thickness of 300 {mu}m and 120 {mu}m. In thinner stabilised solar cells, this measure resulted in enhanced formation of shunts and did not reduce the recombination rate on the back of the solar cell. 3. An additional optimisation step was the introduction of the so-called 'combined method' in which part of the aluminium layer is replaced by silkscreen paste. This combination, with adequate preparation, ensures uniform joining of the ultrathin silicon to the glass carrier. The resulting intermediate layers are highly homogeneous and have good fill factors and current densities for thin solar cells with a si thickness of 60 {mu}m. A decisive argument for the combined method is its near-100% reproducibility. [German] Ziel dieser Arbeit ist es sehr duenne kristalline

  19. A deficiência mental na concepção da liga brasileira de higiene mental Mental disability in the conception of brazilian league of mental hygiene

    Directory of Open Access Journals (Sweden)

    Milena Luckesi de Souza


    Full Text Available O objetivo deste texto é investigar a concepção e as propostas de atendimento escolar destinado aos deficientes mentais segundo o ideário higienista e eugenista difundido pela Liga Brasileira de Higiene Mental (LBHM. Para tanto, utilizamos como fonte primária de estudo os Arquivos Brasileiros de Higiene Mental (ABHM, periódico publicado entre 1925 e 1947. Verificamos que a LBHM expressa diferentes opiniões quanto à concepção e às medidas de intervenção propostas para os deficientes mentais. De um lado, propõe a higienização da população, a ser alcançada com a formação de hábitos sadios através da educação escolar e especificamente da educação higiênica, com a possível adaptação do deficiente ao meio social. De outro, defende uma posição eugênica radical, que apregoa a purificação da raça, a esterilização e exclusão dos ditos degenerados (leprosos, loucos, idiotas, epilépticos, cancerosos, nefrolíticos, tuberculosos, prostitutas, vagabundos e deficientes mentais.The aim of this study is to investigate the conception and proposals of schooling for individuals with mental disability according to the hygienic and eugenic ideology divulged by the Brazilian League for Mental Hygiene (Liga Brasileira de Higiene Mental, LBHM. To this end, we used as a primary source the Brazilian Archives of Mental Hygiene (Arquivos Brasileiros de Higiene Mental, ABHM, a newspaper published from 1925 to 1947. We concluded that there were various opinions in the LBHM about the conception and proposed intervention methods for individuals with mental disability. On one side, there were proposals of population cleansing to be achieved through healthy habits taught in schools, mainly hygienic education, with possible adaptation of the disabled individual to society. On the other hand, there was an extreme eugenic proposal that emphasized race purification, sterilization and exclusion of so-called degenerate individuals (lepers

  20. Herança e ligação em locos de isoenzimas em Genipa americana L. Inheritance and linkage in isozymes loci of Genipa americana L.

    Directory of Open Access Journals (Sweden)

    Alexandre Magno SEBBENN


    Full Text Available A herança e a ligação foram estudadasem quatro locos polimórficos (6pghd-1, Pgi-2,Mdh-1 e Mdh-2 de três sistemas isoenzimáticos deGenipa americana, analisados por eletroforesehorizontal em gel de amido, usando tecidoscoletados de quinze progênies de polinização aberta,procedentes de Moji-Guaçu, Estado de São Paulo.Esses locos segregaram de dois a três alelos.A segregação nesses locos foi homogênea entreárvores. Contudo, existem desvios significativos dasegregação esperada 1:1 para algumas árvores emalguns locos. Desvios significativos da razão desegregação esperada 1:1 foram detectados noslocos Mdh-2 e 6pgdh-1. Não foram detectadasevidências de ligação entre nenhum dos pares delocos avaliados em G. americana e esses podemser utilizados sem restrição para estudos do sistemade reprodução, diversidade e estrutura genética depopulações da espécie.Inheritance and linkage for fourpolymorphic loci (6pghd-1, Pgi-2, Mdh-1 andMdh-2 from three enzyme systems in Genipaamericana were analyzed by horizontal starch gelelectrophoresis using tissues collected from fiftyopen-pollinated families in Moji-Guaçu, São PauloState. These allozyme loci have segregated fromtwo to four alleles per polymorphic locus. Genesegregation on those loci was homogeneous amongtrees. However, there were significant deviationsfrom the expected segregation ratios on some lociand some individual trees. In addition, Mdh-2 and6pgdh-1 loci have shown significant deviationsfrom the 1:1 expected segregation ratio. Linkagedisequilibrium evidences were not detected betweenany two pairs of loci from G. americana and thosecan be used with no restriction to study the matingsystem, genetic diversity, and genetic structure onthe species.

  1. Enhancement of flexural stress and reduction of surface roughness through changes in gas concentrations during high-speed chemical dry thinning of silicon wafers

    Energy Technology Data Exchange (ETDEWEB)

    Kim, I.J. [Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); Lee, N.-E., E-mail: [Department of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of); SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, Gyeonggi-do 440-746 (Korea, Republic of)


    Three-dimensional packaging using through silicon via of ultra-thin Si wafers requires very low residual stress. In this study, the effects of additive gases on root-mean-squared (RMS) surface roughness and flexural stress of Si wafers thinned by the high-speed chemical dry etching (CDE) process were investigated. Direct injection of Ar with NO gases into the reactor during the supply of F radicals from NF{sub 3} remote plasmas was effective in increasing the Si wafer thinning rate and in reducing significant surface roughness. Reduced RMS surface roughness of the thinned Si wafer resulted in high flexural stress. The additional injection of N{sub 2} gas further decreased the surface roughness of the thinned Si wafer and, in turn, increased the flexural stress of the thinned wafers. By adjusting the Ar flow and Q ratio, Q(N{sub 2}) = N{sub 2}/(N{sub 2} + NO), Si wafer thinning rates as high as 23 μm/min and RMS surface roughnesses as small as 10 nm were obtained. Furthermore, it was found that the surface roughness is a critical factor affecting the flexural stress of the thinned Si wafer. These results indicate that the high-speed CDE process using F radicals and directly injected NO/Ar/N{sub 2} gases can be applied to ultra-thin Si wafer thinning with controlled RMS surface roughness and low residual stress. - Highlights: • Chemical dry etching of Si wafers affected by N{sub 2}/(N{sub 2} + NO) flow ratio. • Increasing the flow ratio decreased the thinning rate and surface temperature. • Si wafer thinning rate as high as 23 mm/ min was obtained. • Root mean square surface roughness value drastically decreased from 91 to 1.21 nm. • The strength value of flexural stress increased from 162 to 756 MPa.

  2. Maskless wafer-level microfabrication of optical penetrating neural arrays out of soda-lime glass: Utah Optrode Array. (United States)

    Boutte, Ronald W; Blair, Steve


    Borrowing from the wafer-level fabrication techniques of the Utah Electrode Array, an optical array capable of delivering light for neural optogenetic studies is presented in this paper: the Utah Optrode Array. Utah Optrode Arrays are micromachined out of sheet soda-lime-silica glass using standard backend processes of the semiconductor and microelectronics packaging industries such as precision diamond grinding and wet etching. 9 × 9 arrays with 1100μ m × 100μ m optrodes and a 500μ m back-plane are repeatably reproduced on 2i n wafers 169 arrays at a time. This paper describes the steps and some of the common errors of optrode fabrication.

  3. A Wafer-Bonded, Floating Element Shear-Stress Sensor Using a Geometric Moire Optical Transduction Technique (United States)

    Horowitz, Stephen; Chen, Tai-An; Chandrasekaran, Venkataraman; Tedjojuwono, Ken; Cattafesta, Louis; Nishida, Toshikazu; Sheplak, Mark


    This paper presents a geometric Moir optical-based floating-element shear stress sensor for wind tunnel turbulence measurements. The sensor was fabricated using an aligned wafer-bond/thin-back process producing optical gratings on the backside of a floating element and on the top surface of the support wafer. Measured results indicate a static sensitivity of 0.26 microns/Pa, a resonant frequency of 1.7 kHz, and a noise floor of 6.2 mPa/(square root)Hz.

  4. The role of Gliadel wafers in the treatment of newly diagnosed GBM: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Xing WK


    Full Text Available Wei-kang Xing,1 Chuan Shao,2 Zhen-yu Qi,1 Chao Yang,1 Zhong Wang1 1Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 2Department of Neurosurgery, The Second Clinical Medical College of North Sichuan Medical College, Nanchong, Sichuan, People’s Republic of China Background: Standard treatment for high-grade glioma (HGG includes surgery followed by radiotherapy and/or chemotherapy. Insertion of carmustine wafers into the resection cavity as a treatment for malignant glioma is currently a controversial topic among neurosurgeons. Our meta-analysis focused on whether carmustine wafer treatment could significantly benefit the survival of patients with newly diagnosed glioblastoma multiforme (GBM.Method: We searched the PubMed and Web of Science databases without any restrictions on language using the keywords “Gliadel wafers”, “carmustine wafers”, “BCNU wafers”, or “interstitial chemotherapy” in newly diagnosed GBM for the period from January 1990 to March 2015. Randomized controlled trials (RCTs and cohort studies/clinical trials that compared treatments designed with and without carmustine wafers and which reported overall survival or hazard ratio (HR or survival curves were included in this study. Moreover, the statistical analysis was conducted by the STATA 12.0 software.Results: Six studies including two RCTs and four cohort studies, enrolling a total of 513 patients (223 with and 290 without carmustine wafers, matched the selection criteria. Carmustine wafers showed a strong advantage when pooling all the included studies (HR =0.63, 95% confidence interval (CI =0.49–0.81; P=0.019. However, the two RCTs did not show a statistical increase in survival in the group with carmustine wafer compared to the group without it (HR =0.51, 95% CI =0.18–1.41; P=0.426, while the cohort studies demonstrated a significant survival increase (HR =0.59, 95% CI =0.44–0.79; P<0.0001.Conclusion

  5. High-frequency differential piezoelectric photoacoustic investigation of ion-implanted (100) silicon wafers via laser beam position modulation. (United States)

    Zuccon, J F; Mandelis, A


    An exploratory application of position-modulation photoacoustic imaging of ion-implanted (100)-oriented Si wafers was undertaken to assess its potential as a diagnostic probe in semiconductor processing. Wafer scans were performed using acoustooptic modulation of a 1.06-mum Nd(3+):YAG laser beam up to 0.2 MHz with piezoelectric photoacoustic detection. Sensitivity ranges to ion-implanted parameters (ionic species and fluences) were studied and the capability of the technique to monitor processing-induced damage was established. Results indicate that position-modulated photoacoustic detection offers higher sensitivity than single-beam photothermal imaging and has distinct advantages over other analytical techniques.

  6. Avaliação do desempenho da soldagem em liga de aço 9Cr-5Mo Performance evaluation of welding in steel alloy 9Cr-5Mo

    Directory of Open Access Journals (Sweden)

    Nathália Cândido Figueiredo


    Full Text Available O desenvolvimento de novas ligas de aço requer uma avaliação criteriosa das suas propriedades bem como de seu desempenho frente às condições de operação de acordo com a aplicação a que se destina. Entre estas propriedades pode ser citada a soldabilidade, uma vez que na maioria das vezes estas ligas são empregadas na condição como soldada. O objetivo deste estudo foi analisar o efeito da soldagem MIG em ligas ferríticas contendo 5% de Mo. Corpos de prova da liga solubilizada foram submetidos à soldagem automática pelo processo MIG. Três níveis de energia com diferentes valores de corrente e velocidade de soldagem foram selecionados, resultando em cinco condições de soldagem. A amostra soldada foi submetida à caracterização das regiões termicamente afetadas e do metal de base através de exames metalográficos, por microscopia ótica, MEV e EDX, para verificar o efeito da energia de soldagem na microestrutura das mesmas. Foram realizados ensaios de dureza Vickers visando levantar um perfil de microdureza da liga. Os resultados indicaram a presença de precipitados identificados como sendo martensita. Com exceção aos precipitados observados, nenhum outro defeito, como a presença de trincas, foi observado nos corpos de prova soldado para os diferentes parâmetros empregados.The development of new steel alloys requires a careful evaluation of their properties as well as its performance against the conditions of operation according to the intended application. Among these properties can be cited the weldability, since in most cases, these alloys are used in the welded condition. The aim of this study was to analyze the effect of GMAW in ferritic alloy containing 5% Mo. Specimens annealed alloy were submitted to automatic GMAW. Three energy levels with different values of current and welding speed were selected, resulting in five welding conditions. The welded samples passed through the characterization of heat

  7. Ultrafast-laser dicing of thin silicon wafers: strategies to improve front- and backside breaking strength (United States)

    Domke, Matthias; Egle, Bernadette; Stroj, Sandra; Bodea, Marius; Schwarz, Elisabeth; Fasching, Gernot


    Thin 50-µm silicon wafers are used to improve heat dissipation of chips with high power densities. However, mechanical dicing methods cause chipping at the edges of the separated dies that reduce the mechanical stability. Thermal load changes may then lead to sudden chip failure. Recent investigations showed that the mechanical stability of the cut chips could be increased using ultrashort-pulsed lasers, but only at the laser entrance (front) side and not at the exit (back) side. The goal of this study was to find strategies to improve both front- and backside breaking strength of chips that were cut out of an 8″ wafer with power metallization using an ultrafast laser. In a first experiment, chips were cut by scanning the laser beam in single lines across the wafer using varying fluencies and scan speeds. Three-point bending tests of the cut chips were performed to measure front and backside breaking strengths. The results showed that the breaking strength of both sides increased with decreasing accumulated fluence per scan. Maximum breaking strengths of about 1100 MPa were achieved at the front side, but only below 600 MPa were measured for the backside. A second experiment was carried out to optimize the backside breaking strength. Here, parallel line scans to increase the distance between separated dies and step cuts to minimize the effect of decreasing fluence during scribing were performed. Bending tests revealed that breaking strengths of about 1100 MPa could be achieved also on the backside using the step cut. A reason for the superior performance could be found by calculating the fluence absorbed by the sidewalls. The calculations suggested that an optimal fluence level to minimize thermal side effects and periodic surface structures was achieved due to the step cut. Remarkably, the best breaking strengths values achieved in this study were even higher than the values obtained on state of the art ns-laser and mechanical dicing machines. This is the first

  8. Vico e a ordem de estudos de seu tempo: a ligação entre conhecimento e ética

    Directory of Open Access Journals (Sweden)

    Santos Vladimir Chaves dos


    Full Text Available Vico criticou a racionalidade que predominava em seu tempo e propôs outra como alternativa. No início dessa empreitada, sugeriu o engenho como perfil de inteligência que um programa pedagógico deveria fomentar. O engenho pensado por Vico deveria ser apto a restabelecer a ligação entre conhecimento e ética, algo que, segundo esse filósofo, teria sido abandonado pelas filosofias da moda na virada do século XVII para o XVIII. Além disso, o engenho poderia revigorar a inventio, uma das principais faculdades da retórica clássica, então menosprezada pela filosofia moderna. O ponto de partida do impulso inovador da filosofia de Vico foi a contestação de alguns princípios e conseqüências da filosofia de Descartes, urna grande moda filosófica à época do napolitano.

  9. Low educational level effects on the performance of healthy adults on a Neuropsychological Protocol suggested by the Commission on Neuropsychology of the Liga Brasileira de Epilepsia. (United States)

    dos Santos, Erich Belzunces; Tudesco, Ivanda de Souza Silva; Caboclo, Luis Otávio S F; Yacubian, Elza Márcia T


    To assess cognitive measures and impact of education on cognitive performance (CP) of low educational levels healthy adults (LELHA) on a Neuropsychological Protocol (NP) suggested by the Liga Brasileira de Epilepsia. 138 subjects from an Education Program for Adults divided into two, age and gender matched groups of 69 subjects, answered the NP: Group 1 (mean of 6.9 ± 2.95 months of formal education) and Group 2, 47.8 ± 10 months. Data were compared as z-scores. The mean IQ was 77.1 ± 5.50 and 79.4 ± 3.30 in Groups 1 and 2, respectively (p=0.001). Both performed below the normal curve and Group 1 worse than 2. CP correlated with schooling, especially executive functions (54.1% vs 36.2%) and language (52.9% vs 25.7%). LELHA showed significant cognitive impairment in verbal and visuospatial areas. If these results had been obtained in epilepsy patients they would be interpreted as global cognitive impairment.

  10. A Lateral Differential Resonant Pressure Microsensor Based on SOI-Glass Wafer-Level Vacuum Packaging. (United States)

    Xie, Bo; Xing, Yonghao; Wang, Yanshuang; Chen, Jian; Chen, Deyong; Wang, Junbo


    This paper presents the fabrication and characterization of a resonant pressure microsensor based on SOI-glass wafer-level vacuum packaging. The SOI-based pressure microsensor consists of a pressure-sensitive diaphragm at the handle layer and two lateral resonators (electrostatic excitation and capacitive detection) on the device layer as a differential setup. The resonators were vacuum packaged with a glass cap using anodic bonding and the wire interconnection was realized using a mask-free electrochemical etching approach by selectively patterning an Au film on highly topographic surfaces. The fabricated resonant pressure microsensor with dual resonators was characterized in a systematic manner, producing a quality factor higher than 10,000 (~6 months), a sensitivity of about 166 Hz/kPa and a reduced nonlinear error of 0.033% F.S. Based on the differential output, the sensitivity was increased to two times and the temperature-caused frequency drift was decreased to 25%.

  11. RF Magnetron Sputtering Aluminum Oxide Film for Surface Passivation on Crystalline Silicon Wafers

    Directory of Open Access Journals (Sweden)

    Siming Chen


    Full Text Available Aluminum oxide films were deposited on crystalline silicon substrates by reactive RF magnetron sputtering. The influences of the deposition parameters on the surface passivation, surface damage, optical properties, and composition of the films have been investigated. It is found that proper sputtering power and uniform magnetic field reduced the surface damage from the high-energy ion bombardment to the silicon wafers during the process and consequently decreased the interface trap density, resulting in the good surface passivation; relatively high refractive index of aluminum oxide film is benefic to improve the surface passivation. The negative-charged aluminum oxide film was then successfully prepared. The surface passivation performance was further improved after postannealing by formation of an SiOx interfacial layer. It is demonstrated that the reactive sputtering is an effective technique of fabricating aluminum oxide surface passivation film for low-cost high-efficiency crystalline silicon solar cells.

  12. In situ 2-D piezoelectric wafer active sensors arrays for guided wave damage detection. (United States)

    Yu, Lingyu; Giurgiutiu, Victor


    This paper presented development work of an in situ method for damage detection in thin-wall structures using embedded two-dimensional ultrasonic phased arrays. Piezoelectric wafer active sensors were used to generate and receive guided Lamb waves propagating in the plate-like structure. The development of a generic beamforming algorithm that does not require parallel ray assumption through using full wave propagation paths is described. A virtual beam steering method and device, the embedded ultrasonic structural radar, was implemented as a signal post-processing procedure. Several two-dimensional configurations were investigated and compared with beamforming simulation. Finally, rectangular shape arrays were developed for verifying the generic formulas and omnidirectionality. The rectangular arrays yield good directionality within the 360 degrees full range and are able to detect damage anywhere in the entire plate.

  13. E/M impedance modeling and experimentation for the piezoelectric wafer active sensor (United States)

    Kamas, Tuncay; Giurgiutiu, Victor; Lin, Bin


    This study aimed to develop theoretical models to accurately predict the in-plane (longitudinal) and out-of-plane (thickness-wise) modes of the electromechanical impedance spectroscopy (EMIS) of a piezoelectric wafer active sensor (PWAS). Two main electrical assumptions are applied for both in-plane and thickness mode PWAS-EMIS in one-dimensional simplified analytical models. These assumptions are 1) constant electrical field assumption and 2) constant electrical displacement assumption. The analytical models with two assumptions are compared with one another to understand the prediction accuracy of the models in different vibration modes. Coupled field finite element analysis (CF-FEA) is also conducted with 2D PWAS model under stress-free boundary conditions. The simulations of the simplified analytical models for free PWAS-EMIS under these two assumptions are carried out. The analytical models are validated by corresponding finite element simulations as well as experimental measurements.

  14. Reducing thermal mismatch stress in anodically bonded silicon-glass wafers: theoretical estimation (United States)

    Sinev, Leonid S.; Ryabov, Vladimir T.


    This paper reports the theoretical study and estimations of thermal mismatch stress reduction in anodically bonded silicon-glass stacks by justifiable selection of bonding temperature and glass thickness. This can be done only after prior thorough study of temperature dependence of the linear thermal expansion coefficient of the glass and silicon to be used. We show by analyzing such a dependence of several glass brands that the usual idea of decreasing the bonding process temperature as a solution to the thermal mismatch stress problem can be a failure. Interchanging glass brands during device design is shown to produce very contrasting changes in residual stresses. These results are in good agreement with finite-element modeling. This paper reports there is proportion between glass and silicon wafer thicknesses minimizing thermal mismatch stress at unbonded side of the silicon independently of the bonding or working temperatures chosen.

  15. Probing photo-carrier collection efficiencies of individual silicon nanowire diodes on a wafer substrate (United States)

    Schmitt, S. W.; Brönstrup, G.; Shalev, G.; Srivastava, S. K.; Bashouti, M. Y.; Döhler, G. H.; Christiansen, S. H.


    Vertically aligned silicon nanowire (SiNW) diodes are promising candidates for the integration into various opto-electronic device concepts for e.g. sensing or solar energy conversion. Individual SiNW p-n diodes have intensively been studied, but to date an assessment of their device performance once integrated on a silicon substrate has not been made. We show that using a scanning electron microscope (SEM) equipped with a nano-manipulator and an optical fiber feed-through for tunable (wavelength, power using a tunable laser source) sample illumination, the dark and illuminated current-voltage (I-V) curve of individual SiNW diodes on the substrate wafer can be measured. Surprisingly, the I-V-curve of the serially coupled system composed of SiNW/wafers is accurately described by an equivalent circuit model of a single diode and diode parameters like series and shunting resistivity, diode ideality factor and photocurrent can be retrieved from a fit. We show that the photo-carrier collection efficiency (PCE) of the integrated diode illuminated with variable wavelength and intensity light directly gives insight into the quality of the device design at the nanoscale. We find that the PCE decreases for high light intensities and photocurrent densities, due to the fact that considerable amounts of photo-excited carriers generated within the substrate lead to a decrease in shunting resistivity of the SiNW diode and deteriorate its rectification. The PCE decreases systematically for smaller wavelengths of visible light, showing the possibility of monitoring the effectiveness of the SiNW device surface passivation using the shown measurement technique. The integrated device was pre-characterized using secondary ion mass spectrometry (SIMS), TCAD simulations and electron beam induced current (EBIC) measurements to validate the properties of the characterized material at the single SiNW diode level.Vertically aligned silicon nanowire (SiNW) diodes are promising candidates for


    Directory of Open Access Journals (Sweden)

    S. A. Chizhik


    Full Text Available The advantages of using an atomic force microscopy in manufacturing of submicron integrated circuits are described. The possibilities of characterizing the surface morphology and the etching profile for silicon substrate and bus lines, estimation of the periodicity and size of bus lines, geometrical stability for elementary bus line are shown. Methods of optical and atomic force microcopies are combined in one diagnostic unit. Scanning  probe  microscope  (SPM  200  is  designed  and  produced.  Complex  SPM  200  realizes  nondestructive control of microelectronics elements made on silicon wafers up to 200 mm in diameter and it is introduced by JSC «Integral» for the purpose of operational control, metrology and acceptance of the final product.

  17. Effect of dose and size on defect engineering in carbon cluster implanted silicon wafers (United States)

    Okuyama, Ryosuke; Masada, Ayumi; Shigematsu, Satoshi; Kadono, Takeshi; Hirose, Ryo; Koga, Yoshihiro; Okuda, Hidehiko; Kurita, Kazunari


    Carbon-cluster-ion-implanted defects were investigated by high-resolution cross-sectional transmission electron microscopy toward achieving high-performance CMOS image sensors. We revealed that implantation damage formation in the silicon wafer bulk significantly differs between carbon-cluster and monomer ions after implantation. After epitaxial growth, small and large defects were observed in the implanted region of carbon clusters. The electron diffraction pattern of both small and large defects exhibits that from bulk crystalline silicon in the implanted region. On the one hand, we assumed that the silicon carbide structure was not formed in the implanted region, and small defects formed because of the complex of carbon and interstitial silicon. On the other hand, large defects were hypothesized to originate from the recrystallization of the amorphous layer formed by high-dose carbon-cluster implantation. These defects are considered to contribute to the powerful gettering capability required for high-performance CMOS image sensors.

  18. Radiation hard pixel sensors using high-resistive wafers in a 150 nm CMOS processing line (United States)

    Pohl, D.-L.; Hemperek, T.; Caicedo, I.; Gonella, L.; Hügging, F.; Janssen, J.; Krüger, H.; Macchiolo, A.; Owtscharenko, N.; Vigani, L.; Wermes, N.


    Pixel sensors using 8'' CMOS processing technology have been designed and characterized offering the benefits of industrial sensor fabrication, including large wafers, high throughput and yield, as well as low cost. The pixel sensors are produced using a 150 nm CMOS technology offered by LFoundry in Avezzano. The technology provides multiple metal and polysilicon layers, as well as metal-insulator-metal capacitors that can be employed for AC-coupling and redistribution layers. Several prototypes were fabricated and are characterized with minimum ionizing particles before and after irradiation to fluences up to 1.1 × 1015 neq cm-2. The CMOS-fabricated sensors perform equally well as standard pixel sensors in terms of noise and hit detection efficiency. AC-coupled sensors even reach 100% hit efficiency in a 3.2 GeV electron beam before irradiation.

  19. Anamorphic approach for developing hi-efficiency illumination system to inspect defects on semiconductor wafers (United States)

    Han, Woojun; Yang, Sunseok; Kwon, Ohhyung; Chu, Seungyong; Oh, Seungchul; Jung, Woosung; Kim, Jaisoon


    General approaches to realize higher sensitivity in optical inspection system are using shorter wavelength including UV and higher NA for objective lens. Extreme performances of imaging and illumination systems in a situation of wellmatched to each other are inevitable for the further effort on an effective optical detection of fine defects in patterned wafer. This study focused on the dark field illumination systems satisfying hi areal uniformity and concentration efficiency for the specific conditions of non-symmetric illumination area and critical slanted angle. Three different types of anamorphic dark field illumination systems namely, Far-field Areal Illumination (FAI), Near-field Areal Illumination (NAI) and Farfield Linear Illumination (FLI), are designed and evaluated by brightness, uniformity and concentration efficiency of beam intensity.

  20. High sensitivity detection and characterization of the chemical state of trace element contamination on silicon wafers

    CERN Document Server

    Pianetta, Piero A; Baur, K; Brennan, S; Homma, T; Kubo, N


    Increasing the speed and complexity of semiconductor integrated circuits requires advanced processes that put extreme constraints on the level of metal contamination allowed on the surfaces of silicon wafers. Such contamination degrades the performance of the ultrathin SiO sub 2 gate dielectrics that form the heart of the individual transistors. Ultimately, reliability and yield are reduced to levels that must be improved before new processes can be put into production. It should be noted that much of this metal contamination occurs during the wet chemical etching and rinsing steps required for the manufacture of integrated circuits and industry is actively developing new processes that have already brought the metal contamination to levels beyond the measurement capabilities of conventional analytical techniques. The measurement of these extremely low contamination levels has required the use of synchrotron radiation total reflection X-ray fluorescence (SR-TXRF) where sensitivities 100 times better than conv...

  1. A high aspect ratio silicon-fin FinFET fabricated upon SOI wafer (United States)

    Liaw, Yue-Gie; Liao, Wen-Shiang; Wang, Mu-Chun; Lin, Cheng-Li; Zhou, Bin; Gu, Haoshuang; Li, Deshi; Zou, Xuecheng


    Three dimensional (3-D) FinFET devices with an ultra-high Si-fin aspect ratio (Height/Width = 82.9 nm/8.6 nm) have been developed after integrating a 14 Å nitrided gate oxide upon the silicon on insulator (SOI) wafers through an advanced CMOS logic platform. The drive current (ION), off current (IOFF), subthreshold swing (SS), drain-induced barrier lowering (DIBL) and transistor gate delay of 30 nm gate length (Lg) of FinFETs illustrate the promising device performance. The TCAD simulations demonstrate that both threshold voltage (Vth) and off current can be adjusted appropriately through the full silicidation (FUSI) of CoSi2 gate engineering. Moreover, the drive currents of n- and p-channel FinFETs are able to be further enhanced once applying the raised Source/Drain (S/D) approach technology for reducing the S/D resistance drastically.

  2. Compact infrared cryogenic wafer-level camera: design and experimental validation. (United States)

    de la Barrière, Florence; Druart, Guillaume; Guérineau, Nicolas; Lasfargues, Gilles; Fendler, Manuel; Lhermet, Nicolas; Taboury, Jean


    We present a compact infrared cryogenic multichannel camera with a wide field of view equal to 120°. By merging the optics with the detector, the concept is compatible with both cryogenic constraints and wafer-level fabrication. The design strategy of such a camera is described, as well as its fabrication and integration process. Its characterization has been carried out in terms of the modulation transfer function and the noise equivalent temperature difference (NETD). The optical system is limited by the diffraction. By cooling the optics, we achieve a very low NETD equal to 15 mK compared with traditional infrared cameras. A postprocessing algorithm that aims at reconstructing a well-sampled image from the set of undersampled raw subimages produced by the camera is proposed and validated on experimental images.

  3. Mathematical Description of Wafer-1, a Three-Dimensional Code for LWR Fuel Performance Analysis

    DEFF Research Database (Denmark)

    Kjær-Pedersen, Niels


    This article describes in detail the mathematical formulation used in the WAFER-1 code, which is presently used for three-dimensional analysis of LWR fuel pin performance. The code aims at a prediction of the local stress-strain history in the cladding, especially with regard to the ridging...... phenomenon. To achieve this, a clad model based on shell theory has been developed. This model interacts with a detailed finite difference pellet model which treats radial and transversal cracking in the pellet in a deterministic way, based on certain assumptions with respect to the cracking pattern. Pellet...... and clad creep are taken into account. The inner core of the pellet, bounded by a specified isotherm, may be treated as a viscous material. Axial force exchange between pellet and clad is also included. The axial loading is distributed on the pellet end face with due regard to any pellet dishing...

  4. In-line monitoring of thin oxide on production wafers using large scribe line capacitors (United States)

    Perego, Luca; Duncan, Martin


    In order to guarantee oxide quality for non-volatile memory devices, it is important to be able to monitor defectivity at end-of-line parameter testing. This is the only place where we can screen out the intermediate defectivity which electrical testing cannot detect on all wafers processed. The traditional reliability monitors cannot address this application due to their small sample size, long test time and high cost. In this work, an end-of-line monitor using four scribe line capacitors is proposed. Two gate oxide and two interpoly dielectric structures can be easily measured at parameter testing. Both protected and unprotected capacitors are used to separate out charging effects. These structures can be measured in line after gate definition and can be used to supplement standard gate oxide monitors (GOMs). Using this approach we can quickly detect and correct any deviations in the process that determine oxide quality.

  5. Practical, nondestructive method to profile near-surface and subsurface defects in semiconductor wafers (United States)

    Nokes, Mark A.; Flesher, Pamela; Borden, Peter; DeBusk, Damon K.; Lowell, John K.; Hill, Dale E.; Allen, Gary


    P-type wafers with oxygen concentration in two ranges near 30 ppma and 33 ppma, respectively, were processed through key thermal cycles. These processes were designed to denude the surface of oxygen, begin nucleation, and precipitate a portion of the oxygen in the bulk for intrinsic gettering. The samples were evaluated using nondestructive optical production profiling (OPP), and the results compared with surface photovoltage (SPV) measurements and cleave-and-etch inspection. The denuded zone depth (DZ) and bulk microdefect density (BMD) measured by OPP gave reasonable correlation with the diffusion lengths determined by SPV. The OPP data also showed the same general trends as the cleave- and-etch data. The shallower DZ and higher BMD reported by OPP in contrast to cleave-and-etch, however, are presumably due to the greater sensitivity of OPP to small defects.

  6. Wafer-bonding AlGaInP light emitting diodes with pyramidally patterned metal reflector (United States)

    Zhiyuan, Zuo; Wei, Xia; Gang, Wang; Xiangang, Xu


    We demonstrate and introduce here a pyramidally patterned metal reflector into wafer-bonding AlGaInP light emitting diodes (LEDs) to improve the light extraction efficiency by using a photo-assisted chemical etched GaP:Mg layer. The pyramid patterns were fabricated employing a HF and H2O2 mixed solution in combination with a 532 nm laser on a GaP:Mg surface firstly, and then a gold reflector layer was evaporated onto the patterned GaP:Mg surface. After the whole chip process, the patterned gold reflector structure was confirmed to be efficient for light extraction and a 18.55% enhancement of the electroluminescent flux has been obtained by an integrating sphere, compared to the surface textured LEDs with flat reflectors.

  7. 75 FR 29722 - Foreign-Trade Zone 18-San Jose, CA; Application for Subzone; Lam Research Corporation (Wafer... (United States)


    ... Foreign-Trade Zones Board Foreign-Trade Zone 18--San Jose, CA; Application for Subzone; Lam Research..., requesting special-purpose subzone status for the wafer fabrication equipment manufacturing facilities of Lam Research Corporation (Lam), located in Fremont, California. The application was submitted pursuant to the...

  8. Investigation of Surface Pre-Treatment Methods for Wafer-Level Cu-Cu Thermo-Compression Bonding

    Directory of Open Access Journals (Sweden)

    Koki Tanaka


    Full Text Available To increase the yield of the wafer-level Cu-Cu thermo-compression bonding method, certain surface pre-treatment methods for Cu are studied which can be exposed to the atmosphere before bonding. To inhibit re-oxidation under atmospheric conditions, the reduced pure Cu surface is treated by H2/Ar plasma, NH3 plasma and thiol solution, respectively, and is covered by Cu hydride, Cu nitride and a self-assembled monolayer (SAM accordingly. A pair of the treated wafers is then bonded by the thermo-compression bonding method, and evaluated by the tensile test. Results show that the bond strengths of the wafers treated by NH3 plasma and SAM are not sufficient due to the remaining surface protection layers such as Cu nitride and SAMs resulting from the pre-treatment. In contrast, the H2/Ar plasma–treated wafer showed the same strength as the one with formic acid vapor treatment, even when exposed to the atmosphere for 30 min. In the thermal desorption spectroscopy (TDS measurement of the H2/Ar plasma–treated Cu sample, the total number of the detected H2 was 3.1 times more than the citric acid–treated one. Results of the TDS measurement indicate that the modified Cu surface is terminated by chemisorbed hydrogen atoms, which leads to high bonding strength.

  9. The influence of silicon wafer thickness on characteristics of multijunction solar cells with vertical p—n-junctions

    Directory of Open Access Journals (Sweden)

    Gnilenko A. B.


    Full Text Available A multijunction silicon solar cell with vertical p–n junctions consisted of four serial n+–p–p+-structures was simulated using Silvaco TCAD software package. The dependence of solar cell characteristics on the silicon wafer thickness is investigated for a wide range of values.

  10. Robust Wafer-Level Thin-Film Encapsulation (Packaging) of Microstructures (MEMS) using Low Stress PECVD Silicon Carbide

    NARCIS (Netherlands)

    Rajaraman, V.; Pakula, L.S.; Pham, H.T.M.; Sarro, P.M.; French, P.J.


    This paper presents a new low-cost, CMOS-compatible and robust wafer-level encapsulation technique developed using a stress-optimised PECVD SiC as the capping and sealing material, imparting harsh environment capability. This technique has been applied for the fabrication and encapsulation of a wide


    NARCIS (Netherlands)



    Poly(methyl methacrylate) was grafted onto glass beads, glass slides and silicon wafers using an immobilized radical initiator. The polymeric monolayers had thicknesses varying from a few hundred to 4000 angstrom, being up to 10 times larger than the radii of gyration of comparable free polymers.

  12. Investigation of Polishing Pads Impregnated with Fe and Al2O3 Particles for Single-Crystal Silicon Carbide Wafers

    Directory of Open Access Journals (Sweden)

    Jihng-Kuo Ho


    Full Text Available This study focuses on the development of a novel polishing pad for SiC wafers. Fe and Al2O3 particles were impregnated in a polyurethane matrix, thus forming a fixed abrasive polishing pad. Four types of pads with different compositions of Fe and Al2O3 were fabricated. A combination of loose and fixed polishing methods was used for polishing with the fabricated pads and was investigated to improve the polishing process. The surface characteristics of the polished SiC wafer and the SiC removal rate during polishing using the designed pads were examined and compared with those for SiC polished with a conventional polyurethane pad. Experimental results showed that the removal rate for SiC in the case of polishing with the pads consisting 1 wt % Fe and 3 wt % Al2O3 particles was approximately 73% higher than that observed when polishing using the conventional polyurethane polishing pad. Additionally, the surface roughness of the resulting SiC wafers after polishing with the Fe and Al2O3-impregnated pads was identical to that when using the conventional polyurethane pad, without any surface damage. The results indicated that the Fe and Al2O3-impregnated pads can be effectively used for SiC wafer polishing. When the proposed process was employed for polishing single-crystal SiC, both the polishing time and cost were reduced. This novel design can facilitate the extensive use of single-crystal SiC wafers in the future.

  13. Investigation of dielectric substrates on electrical and optical performance of wafer-scale graphene using non-contact methods (United States)

    Wang, Dong; Ning, Jing; Zhang, Jincheng; Guo, Lixin; Hao, Yue


    Here we systemically discussed the influence of dielectric substrates on the surface morphology, electrical and optical performance of transferred graphene. The electrical properties were investigated using a microwave-probing technique without metal-graphene contact. We found that a complex mechanism governed the influence of the surface properties of the dielectric substrates, such as morphology, hydrophilicity, crystallinity, and polarization, on the performance of the graphene. We also found that graphene on r-Al2O3 was more effective for graphene-based devices with a high carrier mobility of ˜5000 cm2 V-1 s-1. This provides a new method to choose the most suitable substrate for fabricating graphene-based devices.

  14. Heterogeneous integration of lithium niobate and silicon nitride waveguides for wafer-scale photonic integrated circuits on silicon. (United States)

    Chang, Lin; Pfeiffer, Martin H P; Volet, Nicolas; Zervas, Michael; Peters, Jon D; Manganelli, Costanza L; Stanton, Eric J; Li, Yifei; Kippenberg, Tobias J; Bowers, John E


    An ideal photonic integrated circuit for nonlinear photonic applications requires high optical nonlinearities and low loss. This work demonstrates a heterogeneous platform by bonding lithium niobate (LN) thin films onto a silicon nitride (Si3N4) waveguide layer on silicon. It not only provides large second- and third-order nonlinear coefficients, but also shows low propagation loss in both the Si3N4 and the LN-Si3N4 waveguides. The tapers enable low-loss-mode transitions between these two waveguides. This platform is essential for various on-chip applications, e.g., modulators, frequency conversions, and quantum communications.

  15. Graphene nanoribbon field-effect transistors on wafer-scale epitaxial graphene on SiC substrates

    Directory of Open Access Journals (Sweden)

    Wan Sik Hwang


    Full Text Available We report the realization of top-gated graphene nanoribbon field effect transistors (GNRFETs of ∼10 nm width on large-area epitaxial graphene exhibiting the opening of a band gap of ∼0.14 eV. Contrary to prior observations of disordered transport and severe edge-roughness effects of graphene nanoribbons (GNRs, the experimental results presented here clearly show that the transport mechanism in carefully fabricated GNRFETs is conventional band-transport at room temperature and inter-band tunneling at low temperature. The entire space of temperature, size, and geometry dependent transport properties and electrostatics of the GNRFETs are explained by a conventional thermionic emission and tunneling current model. Our combined experimental and modeling work proves that carefully fabricated narrow GNRs behave as conventional semiconductors and remain potential candidates for electronic switching devices.

  16. 11.72 sq cm SiC Wafer-scale Interconnected 64 kA PiN Diode (United States)


    breakdown voltage yield of 83% was achieved. The diodes selected demonstrate sharp onsets of breakdown voltage as illustrated in Fig. 3. Diodes...645-648, pp. 1017-1020, 2010. [2] D. Peters, W. Bartsch , B. Thomas, and R. Sommer, ―6.5 kV SiC PiN Diodes with Improved Forward Characteristics

  17. Semiconductor nanowires directly grown on graphene--towards wafer scale transferable nanowire arrays with improved electrical contact. (United States)

    Alper, John P; Gutes, Albert; Carraro, Carlo; Maboudian, Roya


    We present for the first time the growth of dense arrays of silicon and silicon carbide nanowires directly on graphene as well as methods of transferring these novel hybrids to arbitrary substrates. Improved electrical contact for SiC nanowire/graphene hybrid is demonstrated in the application of a robust supercapacitor electrode.

  18. Avaliação da fundibilidade de uma liga de cobalto-cromo Castability evaluation of a cobalt-chromium alloy

    Directory of Open Access Journals (Sweden)

    Adriana da Fonte Porto CARREIRO


    Full Text Available Neste trabalho propusemo-nos a avaliar a fundibilidade de uma liga de cobalto-cromo (VERA-PDI em função da utilização de três revestimentos: Knebel (aglutinado por sílica, Termocast e Wirovest (aglutinados por fosfato e duas temperaturas de aquecimento para o molde (900°C e 950°C. Para a execução do teste foi utilizado o método descrito por HINMAN et al.9 (1985. O método de fundição foi o de cera perdida sob chama de gás-oxigênio. Os dados obtidos foram submetidos a análise estatística e demonstraram não haver diferença estatisticamente significante para os revestimentos Knebel e Wirovest, e diferença estatisticamente significante ao nível de 0,1% para o revestimento Termocast quando da variação da temperatura de aquecimento do molde. Quando analisamos os revestimentos sob temperatura do molde de 900°C verificamos diferença estatisticamente significante entre Knebel e Termocast e Knebel e Wirovest ao nível de 0,1%, e diferença entre Termocast e Wirovest ao nível de 5%. Para a temperatura de 950°C houve diferença estatisticamente significante ao nível de 0,1% entre todos os revestimentos. Dentro dos parâmetros utilizados neste estudo pudemos concluir que, para a liga VERA-PDI, a utilização do revestimento Knebel e temperatura de aquecimento do molde de 950°C proporcionaram melhores resultados quanto à fundibilidade.The purpose of this study was to evaluate the castability of a cobalt-chromium alloy (Vera-PDI using three investments: Knebel (agglutinated by silica, Termocast and Wirovest (both agglutinated by phosphate at two molding temperatures (900°C and 950°C; using HINMAN et al.9 (1985; methodology. The casting method of using a wax and gas-oxygen flame was used. There was no significant statistical difference between the Knebel and Wirovest investments; however, there was a statistically significant difference for Termocast investment (P < 0.1 at the different temperatures. When analyzing the

  19. The terminal immunoglobulin-like repeats of LigA and LigB of Leptospira enhance their binding to gelatin binding domain of fibronectin and host cells.

    Directory of Open Access Journals (Sweden)

    Yi-Pin Lin

    Full Text Available Leptospira spp. are pathogenic spirochetes that cause the zoonotic disease leptospirosis. Leptospiral immunoglobulin (Ig-like protein B (LigB contributes to the binding of Leptospira to extracellular matrix proteins such as fibronectin, fibrinogen, laminin, elastin, tropoelastin and collagen. A high-affinity Fn-binding region of LigB has been localized to LigBCen2, which contains the partial 11th and full 12th Ig-like repeats (LigBCen2R and 47 amino acids of the non-repeat region (LigBCen2NR of LigB. In this study, the gelatin binding domain of fibronectin was shown to interact with LigBCen2R (K(D = 1.91+/-0.40 microM. Not only LigBCen2R but also other Ig-like domains of Lig proteins including LigAVar7'-8, LigAVar10, LigAVar11, LigAVar12, LigAVar13, LigBCen7'-8, and LigBCen9 bind to GBD. Interestingly, a large gain in affinity was achieved through an avidity effect, with the terminal domains, 13th (LigA or 12th (LigB Ig-like repeat of Lig protein (LigAVar7'-13 and LigBCen7'-12 enhancing binding affinity approximately 51 and 28 fold, respectively, compared to recombinant proteins without this terminal repeat. In addition, the inhibited effect on MDCKs cells can also be promoted by Lig proteins with terminal domains, but these two domains are not required for gelatin binding domain binding and cell adhesion. Interestingly, Lig proteins with the terminal domains could form compact structures with a round shape mediated by multidomain interaction. This is the first report about the interaction of gelatin binding domain of Fn and Lig proteins and provides an example of Lig-gelatin binding domain binding mediating bacterial-host interaction.

  20. ¿Tienen los árbitros de fútbol influencia en los resultados de la liga española?

    Directory of Open Access Journals (Sweden)

    Sala Garrido, Ramon


    Full Text Available RESUMEN El trabajo analiza los resultados de las temporadas 2002-03 a 2007-08 de la Liga Española de Primera División con el fin de determinar la influencia de los árbitros en los mismos, tanto desde el punto de vista del tiempo extra que añaden, como de las sanciones disciplinarias (faltas y tarjetas a los equipos. Se estudia también la influencia que sobre las decisiones del árbitro puede tener la afición del equipo local. Se concluye que no puede afirmarse que la exista influencia arbitral de forma generalizada, aunque algunos árbitros en concreto sí parecen influir en los resultados. El análisis permite también confirmar algo ya sabido, el escaso valor del tiempo extra para cambiar el resultado de un partido.ABSTRACT This paper analyses the results of the 2002-03 to 2007-08 seasons of the First Division Spanish Football League with the aim of determining the influence of referees in them, both from the point of view of the extra time they allow, as well as the disciplinary sanctions (fouls and cards given to the teams. The influence that the supporters of the local team may have over the referee’s decisions is also studied. The conclusion is that it is not possible to confirm the existence of referee influence in a general sense, although some specific referees do seem to have an influence on the results. This analysis also confirms something already known, which is the minimal value of extra time in changing the results of a match.