Tin (Sn) for enhancing performance in silicon CMOS

KAUST Repository

Hussain, Aftab M.; Fahad, Hossain M.; Singh, Nirpendra; Sevilla, Galo T.; Schwingenschlö gl, Udo; Hussain, Muhammad Mustafa

2013-01-01

We study a group IV element: tin (Sn) by integrating it into silicon lattice, to enhance the performance of silicon CMOS. We have evaluated the electrical properties of the SiSn lattice by performing simulations using First-principle studies, followed by experimental device fabrication and characterization. We fabricated high-κ/metal gate based Metal-Oxide-Semiconductor capacitors (MOSCAPs) using SiSn as channel material to study the impact of Sn integration into silicon. © 2013 IEEE.

Tin (Sn) for enhancing performance in silicon CMOS

KAUST Repository

Hussain, Aftab M.

2013-10-01

We study a group IV element: tin (Sn) by integrating it into silicon lattice, to enhance the performance of silicon CMOS. We have evaluated the electrical properties of the SiSn lattice by performing simulations using First-principle studies, followed by experimental device fabrication and characterization. We fabricated high-κ/metal gate based Metal-Oxide-Semiconductor capacitors (MOSCAPs) using SiSn as channel material to study the impact of Sn integration into silicon. © 2013 IEEE.

Threshold voltage control in TmSiO/HfO2 high-k/metal gate MOSFETs

Science.gov (United States)

Dentoni Litta, E.; Hellström, P.-E.; Östling, M.

2015-06-01

High-k interfacial layers have been proposed as a way to extend the scalability of Hf-based high-k/metal gate CMOS technology, which is currently limited by strong degradations in threshold voltage control, channel mobility and device reliability when the chemical oxide (SiOx) interfacial layer is scaled below 0.4 nm. We have previously demonstrated that thulium silicate (TmSiO) is a promising candidate as a high-k interfacial layer, providing competitive advantages in terms of EOT scalability and channel mobility. In this work, the effect of the TmSiO interfacial layer on threshold voltage control is evaluated, showing that the TmSiO/HfO2 dielectric stack is compatible with threshold voltage control techniques commonly used with SiOx/HfO2 stacks. Specifically, we show that the flatband voltage can be set in the range -1 V to +0.5 V by the choice of gate metal and that the effective workfunction of the stack is properly controlled by the metal workfunction in a gate-last process flow. Compatibility with a gate-first approach is also demonstrated, showing that integration of La2O3 and Al2O3 capping layers can induce a flatband voltage shift of at least 150 mV. Finally, the effect of the annealing conditions on flatband voltage is investigated, finding that the duration of the final forming gas anneal can be used as a further process knob to tune the threshold voltage. The evaluation performed on MOS capacitors is confirmed by the fabrication of TmSiO/HfO2/TiN MOSFETs achieving near-symmetric threshold voltages at sub-nm EOT.

Gate-first integration of tunable work function metal gates of different thicknesses into high-k metal gates CMOS FinFETs for multi- VTh engineering

KAUST Repository

Hussain, Muhammad Mustafa; Smith, Casey Eben; Harris, Harlan Rusty; Young, Chadwin; Tseng, Hsinghuang; Jammy, Rajarao

2010-01-01

Gate-first integration of tunable work function metal gates of different thicknesses (320 nm) into high-k/metal gates CMOS FinFETs was demonstrated to achieve multiple threshold voltages (VTh) for 32-nm technology and beyond logic, memory, input/output, and system-on-a-chip applications. The fabricated devices showed excellent short-channel effect immunity (drain-induced barrier lowering ∼ 40 mV/V), nearly symmetric VTh, low T inv(∼ 1.4 nm), and high Ion(∼780μAμm) for N/PMOS without any intentional strain enhancement. © 2006 IEEE.

Gate-first integration of tunable work function metal gates of different thicknesses into high-k metal gates CMOS FinFETs for multi- VTh engineering

KAUST Repository

Hussain, Muhammad Mustafa

2010-03-01

Gate-first integration of tunable work function metal gates of different thicknesses (320 nm) into high-k/metal gates CMOS FinFETs was demonstrated to achieve multiple threshold voltages (VTh) for 32-nm technology and beyond logic, memory, input/output, and system-on-a-chip applications. The fabricated devices showed excellent short-channel effect immunity (drain-induced barrier lowering ∼ 40 mV/V), nearly symmetric VTh, low T inv(∼ 1.4 nm), and high Ion(∼780μAμm) for N/PMOS without any intentional strain enhancement. © 2006 IEEE.

Gate tunneling current and quantum capacitance in metal-oxide-semiconductor devices with graphene gate electrodes

Science.gov (United States)

An, Yanbin; Shekhawat, Aniruddh; Behnam, Ashkan; Pop, Eric; Ural, Ant

2016-11-01

Metal-oxide-semiconductor (MOS) devices with graphene as the metal gate electrode, silicon dioxide with thicknesses ranging from 5 to 20 nm as the dielectric, and p-type silicon as the semiconductor are fabricated and characterized. It is found that Fowler-Nordheim (F-N) tunneling dominates the gate tunneling current in these devices for oxide thicknesses of 10 nm and larger, whereas for devices with 5 nm oxide, direct tunneling starts to play a role in determining the total gate current. Furthermore, the temperature dependences of the F-N tunneling current for the 10 nm devices are characterized in the temperature range 77-300 K. The F-N coefficients and the effective tunneling barrier height are extracted as a function of temperature. It is found that the effective barrier height decreases with increasing temperature, which is in agreement with the results previously reported for conventional MOS devices with polysilicon or metal gate electrodes. In addition, high frequency capacitance-voltage measurements of these MOS devices are performed, which depict a local capacitance minimum under accumulation for thin oxides. By analyzing the data using numerical calculations based on the modified density of states of graphene in the presence of charged impurities, it is shown that this local minimum is due to the contribution of the quantum capacitance of graphene. Finally, the workfunction of the graphene gate electrode is extracted by determining the flat-band voltage as a function of oxide thickness. These results show that graphene is a promising candidate as the gate electrode in metal-oxide-semiconductor devices.

Alkaline earth metal doped tin oxide as a novel oxygen storage material

Energy Technology Data Exchange (ETDEWEB)

Dong, Qiang, E-mail: dong@tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku Sendai 980-8577 (Japan); Yin, Shu; Yoshida, Mizuki; Wu, Xiaoyong; Liu, Bin [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku Sendai 980-8577 (Japan); Miura, Akira; Takei, Takahiro; Kumada, Nobuhiro [Department of Research Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Miyamae cho-7, Kofu 400-8511 (Japan); Sato, Tsugio [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku Sendai 980-8577 (Japan)

2015-09-15

Alkaline earth metal doped tin oxide (SnO{sub 2}) hollow nanospheres with a diameter of 50 nm have been synthesized successfully via a facial solvothermal route in a very simple system composed of only ethanol, acetic acid, SnCl{sub 4}·5H{sub 2}O and A(NO{sub 3}){sub 2}·xH{sub 2}O (A = Mg, Ca, Sr, Ba). The synthesized undoped SnO{sub 2} and A-doped SnO{sub 2} hollow nanospheres were characterized by the oxygen storage capacity (OSC), X-ray diffraction, transmission electron microscopy and the Brunauer–Emmet–Teller (BET) technique. The OSC values of all samples were measured using thermogravimetric-differential thermal analysis. The incorporation of alkaline earth metal ion into tin oxide greatly enhanced the thermal stability and OSC. Especially, Ba-doped SnO{sub 2} hollow nanospheres calcined at 1000 °C for 20 h with a BET surface area of 61 m{sup 2} g{sup −1} exhibited the considerably high OSC of 457 μmol-O g{sup −1} and good thermal stability. Alkaline earth metal doped tin oxide has the potential to be a novel oxygen storage material.

Plasma-Induced Damage on the Reliability of Hf-Based High-k/Dual Metal-Gates Complementary Metal Oxide Semiconductor Technology

International Nuclear Information System (INIS)

Weng, W.T.; Lin, H.C.; Huang, T.Y.; Lee, Y.J.; Lin, H.C.

2009-01-01

This study examines the effects of plasma-induced damage (PID) on Hf-based high-k/dual metal-gates transistors processed with advanced complementary metal-oxide-semiconductor (CMOS) technology. In addition to the gate dielectric degradations, this study demonstrates that thinning the gate dielectric reduces the impact of damage on transistor reliability including the positive bias temperature instability (PBTI) of n-channel metal-oxide-semiconductor field-effect transistors (NMOSFETs) and the negative bias temperature instability (NBTI) of p-channel MOSFETs. This study shows that high-k/metal-gate transistors are more robust against PID than conventional SiO 2 /poly-gate transistors with similar physical thickness. Finally this study proposes a model that successfully explains the observed experimental trends in the presence of PID for high-k/metal-gate CMOS technology.

Molybdenum-tin as a solar cell metallization system

Science.gov (United States)

Boyd, D. W.; Radics, C.

1981-01-01

The operations of solar cell manufacture are briefly examined. The formation of reliable, ohmic, low-loss, and low-cost metal contacts on solar cells is a critical process step in cell manufacturing. In a commonly used process, low-cost metallization is achieved by screen printing a metal powder-glass frit ink on the surface of the Si surface and the conductive metal powder. A technique utilizing a molybdenum-tin alloy for the metal contacts appears to lower the cost of materials and to reduce process complexity. The ink used in this system is formulated from MoO3 with Sn powder and a trace amount of titanium resonate. Resistive losses of the resulting contacts are low because the ink contains no frit. The MoO3 is finally melted and reduced in forming gas (N2+H2) to Mo metal. The resulting Mo is highly reactive which facilitates the Mo-Si bonding.

Cleaning Challenges of High-κ/Metal Gate Structures

KAUST Repository

Hussain, Muhammad Mustafa; Shamiryan, Denis G.; Paraschiv, Vasile; Sano, Kenichi; Reinhardt, Karen A.

2010-01-01

High-κ/metal gates are used as transistors for advanced logic applications to improve speed and eliminate electrical issues associated with polySi and SiO2 gates. Various integration schemes are possible and will be discussed, such as dual gate, gate-first, and gate-last, both of which require specialized cleaning and etching steps. Specific areas of discussion will include cleaning and conditioning of the silicon surface, forming a high-quality chemical oxide, removal of the high-κ dielectric with selectivity to the SiO2 layer, cleaning and residue removal after etching, and prevention of galvanic corrosion during cleaning. © 2011 Scrivener Publishing LLC. All rights reserved.

Cleaning Challenges of High-κ/Metal Gate Structures

KAUST Repository

Hussain, Muhammad Mustafa

2010-12-20

High-κ/metal gates are used as transistors for advanced logic applications to improve speed and eliminate electrical issues associated with polySi and SiO2 gates. Various integration schemes are possible and will be discussed, such as dual gate, gate-first, and gate-last, both of which require specialized cleaning and etching steps. Specific areas of discussion will include cleaning and conditioning of the silicon surface, forming a high-quality chemical oxide, removal of the high-κ dielectric with selectivity to the SiO2 layer, cleaning and residue removal after etching, and prevention of galvanic corrosion during cleaning. © 2011 Scrivener Publishing LLC. All rights reserved.

Dipole controlled metal gate with hybrid low resistivity cladding for gate-last CMOS with low Vt

KAUST Repository

Hinkle, Christopher L.; Galatage, Rohit V.; Chapman, Richard A.; Vogel, Eric M.; Alshareef, Husam N.; Freeman, Clive M.; Wimmer, Erich; Niimi, Hiroaki; Li-Fatou, Andrei V.; Shaw, Judy B.; Chambers, James J.

2010-01-01

In this contribution, NMOS and PMOS band edge effective work function (EWF) and correspondingly low Vt are demonstrated using standard fab materials and processes in a gate-last scheme. For NMOS, the use of an Al cladding layer results in Vt = 0.08 V consistent with NMOS EWF = 4.15 eV. Migration of the Al cladding into the TiN and a relatively low oxygen concentration near the TiN/HfO2 interface are responsible for the low EWF. For PMOS, employing a W cladding layer along with a post-TiN anneal in an oxidizing ambient results in elevated oxygen concentration near the TiN/HfO2 interface and Vt = -0.20 V consistent with a PMOS EWF = 5.05 eV. First-principles calculations indicate N atoms displaced from the TiN during the oxidizing anneal form dipoles at the TiN/HfO2 interface that play a critical role in determining the PMOS EWF. © 2010 IEEE.

Dipole controlled metal gate with hybrid low resistivity cladding for gate-last CMOS with low Vt

KAUST Repository

Hinkle, Christopher L.

2010-06-01

In this contribution, NMOS and PMOS band edge effective work function (EWF) and correspondingly low Vt are demonstrated using standard fab materials and processes in a gate-last scheme. For NMOS, the use of an Al cladding layer results in Vt = 0.08 V consistent with NMOS EWF = 4.15 eV. Migration of the Al cladding into the TiN and a relatively low oxygen concentration near the TiN/HfO2 interface are responsible for the low EWF. For PMOS, employing a W cladding layer along with a post-TiN anneal in an oxidizing ambient results in elevated oxygen concentration near the TiN/HfO2 interface and Vt = -0.20 V consistent with a PMOS EWF = 5.05 eV. First-principles calculations indicate N atoms displaced from the TiN during the oxidizing anneal form dipoles at the TiN/HfO2 interface that play a critical role in determining the PMOS EWF. © 2010 IEEE.

A Difference in Using Atomic Layer Deposition or Physical Vapour Deposition TiN as Electrode Material in Metal-Insulator-Metal and Metal-Insulator-Silicon Capacitors

NARCIS (Netherlands)

Groenland, A.W.; Wolters, Robertus A.M.; Kovalgin, Alexeij Y.; Schmitz, Jurriaan

2011-01-01

In this work, metal-insulator-metal (MIM) and metal-insulator-silicon (MIS) capacitors are studied using titanium nitride (TiN) as the electrode material. The effect of structural defects on the electrical properties on MIS and MIM capacitors is studied for various electrode configurations. In the

Tin

Science.gov (United States)

Kamilli, Robert J.; Kimball, Bryn E.; Carlin, James F.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Tin (Sn) is one of the first metals to be used by humans. Almost without exception, tin is used as an alloy. Because of its hardening effect on copper, tin was used in bronze implements as early as 3500 B.C. The major uses of tin today are for cans and containers, construction materials, transportation materials, and solder. The predominant ore mineral of tin, by far, is cassiterite (SnO2).In 2015, the world’s total estimated mine production of tin was 289,000 metric tons of contained tin. Total world reserves at the end of 2016 were estimated to be 4,700,000 metric tons. China held about 24 percent of the world’s tin reserves and accounted for 38 percent of the world’s 2015 production of tin.The proportion of scrap used in tin production is between 10 and 25 percent. Unlike many metals, tin recycling is relatively efficient, and the fraction of tin in discarded products that get recycled is greater than 50 percent.Only about 20 percent of the world’s identified tin resources occur as primary hydrothermal hard-rock veins, or lodes. These lodes contain predominantly high-temperature minerals and almost invariably occur in close association with silicic, peraluminous granites. About 80 percent of the world’s identified tin resources occur as unconsolidated secondary or placer deposits in riverbeds and valleys or on the sea floor. The largest concentration of both onshore and offshore placers is in the extensive tin belt of Southeast Asia, which stretches from China in the north, through Thailand, Burma (also referred to as Myanmar), and Malaysia, to the islands of Indonesia in the south. Furthermore, tin placers are almost always found closely allied to the granites from which they originate. Other countries with significant tin resources are Australia, Bolivia, and Brazil.Most hydrothermal tin deposits belong to what can be thought of as a superclass of porphyry-greisen deposits. The hydrothermal tin deposits are all characterized by a close spatial

Copper-silver-titanium-tin filler metal for direct brazing of structural ceramics

Science.gov (United States)

Moorhead, Arthur J.

1988-04-05

A method of joining ceramics and metals to themselves and to one another at about 800.degree. C. is described using a brazing filler metal consisting essentially of 35 to 50 at. % copper, 40 to 50 at. % silver, 1 to 15 at. % titanium, and 2 to 8 at. % tin. This method produces strong joints that can withstand high service temperatures and oxidizing environments.

Heavy metal and radioactivity measurements in fish, water, plants and soils in tin-mining pool

International Nuclear Information System (INIS)

Muhammad Samudi Yasir; Norlaili Ahmad Kabir; Redzuwan Yahaya; Amran Abdul Majid

2008-01-01

Malaysia aggressively reclaimed most of their disused tin-mining pool especially for agricultural activities, freshwater fish farming area, recreational area, houses area and even as an industrial area. Past mining activities might induced the concentration of naturally occurring radionuclide (NORM) and heavy metal at the disused tin-mining pool ecosystem. A study has been conducted on the status of heavy metal (Hf, Zr, Mn, Cu, Zn, As, Cd, Sn, Sb, Ba, Hg and Pb) concentration and naturally occurring radionuclide activity in fish, water, plants and sediments at three different disused tin-mining pool near by Sepang and Puchong, Selangor Darul Ehsan. Sample of fish, water, plant and sediment being analyze using ICP-MS. The concentrations of heavy metal in sediment and plant are higher than its concentrations in fish and followed by water. The highest concentration of heavy metal in sediment and water is barium, whereas the highest concentration of heavy metal in fish and plant is zinc and manganese. The result also showed that only mercury level in fish collected in second disused tin-mining pool (0.53 ± 0.20 mg/ kg) is exceed the maximum limit (0.5 mg/ kg) prescribe by the Malaysian Food Act (Act 281). The activity of U-238 and Th-232 in sediment was found to be relatively higher than its activity in fish, plant or water (30.76 ± 2.71 to 35.34 ± 0.27 Bq/ kg) and (9.37 ± 2.30 - 18.86 ± 2.60 Bq/ kg). The determination of K-40 activity showed that it is highly contained in plant and fish than in sediment or water. (author)

TiN nanoparticles on CNT-graphene hybrid support as noble-metal-free counter electrode for quantum-dot-sensitized solar cells.

Science.gov (United States)

Youn, Duck Hyun; Seol, Minsu; Kim, Jae Young; Jang, Ji-Wook; Choi, Youngwoo; Yong, Kijung; Lee, Jae Sung

2013-02-01

The development of an efficient noble-metal-free counter electrode is crucial for possible applications of quantum-dot-sensitized solar cells (QDSSCs). Herein, we present TiN nanoparticles on a carbon nanotube (CNT)-graphene hybrid support as a noble-metal-free counter electrode for QDSSCs employing a polysulfide electrolyte. The resulting TiN/CNT-graphene possesses an extremely high surface roughness, a good metal-support interaction, and less aggregation relative to unsupported TiN; it also has superior solar power conversion efficiency (4.13 %) when applying a metal mask, which is much higher than that of the state-of-the-art Au electrode (3.35 %). Based on electrochemical impedance spectroscopy measurements, the enhancement is ascribed to a synergistic effect between TiN nanoparticles and the CNT-graphene hybrid, the roles of which are to provide active sites for the reduction of polysulfide ions and electron pathways to TiN nanoparticles, respectively. The combination of graphene and CNTs leads to a favorable morphology that prevents stacking of graphene or bundling of CNTs, which maximizes the contact of the support with TiN nanoparticles and improves electron-transfer capability relative to either carbon material alone. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gate-last TiN/HfO2 band edge effective work functions using low-temperature anneals and selective cladding to control interface composition

KAUST Repository

Hinkle, C. L.; Galatage, R. V.; Chapman, R. A.; Vogel, E. M.; Alshareef, Husam N.; Freeman, C.; Christensen, M.; Wimmer, E.; Niimi, H.; Li-Fatou, A.; Shaw, J. B.; Chambers, J. J.

2012-01-01

Silicon N-metal-oxide-semiconductor (NMOS) and P-metal-oxide-semiconductor (PMOS) band edge effective work functions and the correspondingly low threshold voltages (Vt) are demonstrated using standard fab materials and processes in a gate-last scheme employing low-temperature anneals and selective cladding layers. Al diffusion from the cladding to the TiN/HfO2interface during forming gas anneal together with low O concentration in the TiN enables low NMOS Vt. The use of non-migrating W cladding along with experimentally detected N-induced dipoles, produced by increased oxygen in the TiN, facilitates low PMOS Vt.

Gate-last TiN/HfO2 band edge effective work functions using low-temperature anneals and selective cladding to control interface composition

KAUST Repository

Hinkle, C. L.

2012-04-09

Silicon N-metal-oxide-semiconductor (NMOS) and P-metal-oxide-semiconductor (PMOS) band edge effective work functions and the correspondingly low threshold voltages (Vt) are demonstrated using standard fab materials and processes in a gate-last scheme employing low-temperature anneals and selective cladding layers. Al diffusion from the cladding to the TiN/HfO2interface during forming gas anneal together with low O concentration in the TiN enables low NMOS Vt. The use of non-migrating W cladding along with experimentally detected N-induced dipoles, produced by increased oxygen in the TiN, facilitates low PMOS Vt.

Transparently wrap-gated semiconductor nanowire arrays for studies of gate-controlled photoluminescence

Energy Technology Data Exchange (ETDEWEB)

Nylund, Gustav; Storm, Kristian; Torstensson, Henrik; Wallentin, Jesper; Borgström, Magnus T.; Hessman, Dan; Samuelson, Lars [Solid State Physics, Nanometer Structure Consortium, Lund University, Box 118, S-221 00 Lund (Sweden)

2013-12-04

We present a technique to measure gate-controlled photoluminescence (PL) on arrays of semiconductor nanowire (NW) capacitors using a transparent film of Indium-Tin-Oxide (ITO) wrapping around the nanowires as the gate electrode. By tuning the wrap-gate voltage, it is possible to increase the PL peak intensity of an array of undoped InP NWs by more than an order of magnitude. The fine structure of the PL spectrum reveals three subpeaks whose relative peak intensities change with gate voltage. We interpret this as gate-controlled state-filling of luminescing quantum dot segments formed by zincblende stacking faults in the mainly wurtzite NW crystal structure.

Studies on Cementation of Tin on Copper and Tin Stripping from Copper Substrate

Directory of Open Access Journals (Sweden)

Rudnik E.

2016-06-01

Full Text Available Cementation of tin on copper in acid chloride-thiourea solutions leads to the formation of porous layers with a thickness dependent on the immersion time. The process occurs via Sn(II-Cu(I mechanism. Chemical stripping of tin was carried out in alkaline and acid solutions in the presence of oxidizing agents. It resulted in the dissolution of metallic tin, but refractory Cu3Sn phase remained on the copper surface. Electrochemical tin stripping allows complete tin removal from the copper substrate, but porosity and complex phase composition of the tin coating do not allow monitoring the process in unambiguous way.

Design and Optimization of 22 nm Gate Length High-k/Metal gate NMOS Transistor

International Nuclear Information System (INIS)

Afifah Maheran A H; Menon P S; Shaari, S; Elgomati, H A; Salehuddin, F; Ahmad, I

2013-01-01

In this paper, we invented the optimization experiment design of a 22 nm gate length NMOS device which uses a combination of high-k material and metal as the gate which was numerically developed using an industrial-based simulator. The high-k material is Titanium dioxide (TiO 2 ), while the metal gate is Tungsten Silicide (WSi x ). The design is optimized using the L9 Taguchi method to get the optimum parameter design. There are four process parameters and two noise parameters which were varied for analyzing the effect on the threshold voltage (V th ). The objective of this experiment is to minimize the variance of V th where Taguchi's nominal-the-best signal-to-noise ratio (S/N Ratio) was used. The best settings of the process parameters were determined using Analysis of Mean (ANOM) and analysis of variance (ANOVA) to reduce the variability of V th . The results show that the V th values have least variance and the mean value can be adjusted to 0.306V ±0.027 for the NMOS device which is in line with projections by the ITRS specifications.

Elaboration and test of the method of separation of alkaline metals ions with tin phosphate

International Nuclear Information System (INIS)

Smirnov, G.I.; Chernyak, A.S.; Kostromina, O.N.; Kachur, N.Ya.; Shpeyzer, B.G.

1986-01-01

Present work is devoted to elaboration and test of the method of separation of alkaline metals ions with tin phosphate. Thus, the isotherms of sorption of lithium, sodium, potassium, rubidium and cesium ions with amorphous tin phosphate depending on their concentration, ph of solution, sorbent quantity are obtained. The parameters of extraction of potassium microquantities from sodium salts are defined. Ultra pure sodium chloride, sodium iodide, sodium sulphate, sodium nitrate, sodium nitrite, sodium phosphate are synthesized.

Shanghai Futures Exchange Incorporates Nickel & Tin to Finish Adjustment of Nonferrous Metal Index

Institute of Scientific and Technical Information of China (English)

2015-01-01

After close of trading on August 12,the nonferrous metal futures price index adjustment&optimization; work of Shanghai Futures Exchange was completed and formally took effect.The new compilation plan incorporated two newly marketed varieties of nickel and tin,and made adjustment and optimization in

SEMICONDUCTOR TECHNOLOGY: TaN wet etch for application in dual-metal-gate integration technology

Science.gov (United States)

Yongliang, Li; Qiuxia, Xu

2009-12-01

Wet-etch etchants and the TaN film method for dual-metal-gate integration are investigated. Both HF/HN O3/H2O and NH4OH/H2O2 solutions can etch TaN effectively, but poor selectivity to the gate dielectric for the HF/HNO3/H2O solution due to HF being included in HF/HNO3/H2O, and the fact that TaN is difficult to etch in the NH4OH/H2O2 solution at the first stage due to the thin TaOxNy layer on the TaN surface, mean that they are difficult to individually apply to dual-metal-gate integration. A two-step wet etching strategy using the HF/HNO3/H2O solution first and the NH4OH/H2O2 solution later can fully remove thin TaN film with a photo-resist mask and has high selectivity to the HfSiON dielectric film underneath. High-k dielectric film surfaces are smooth after wet etching of the TaN metal gate and MOSCAPs show well-behaved C-V and Jg-Vg characteristics, which all prove that the wet etching of TaN has little impact on electrical performance and can be applied to dual-metal-gate integration technology for removing the first TaN metal gate in the PMOS region.

Trace metal levels in soils and vegetation from some tin mining ...

African Journals Online (AJOL)

Samples of soil and vegetation from some tin mining areas of Nigeria were analysed for lead, zinc, copper and cadmium content. The levels of Pb and Zn were found to be high in some samples. The mean levels of metal in the vegetation were: 86.6+ 36.0, 49.6+ 28.3, 12.6+4.8 and 1.4+0.8 µgg-1 dry weight for Pb, Zn, Cu ...

Optimum source/drain overlap design for 16 nm high-k/metal gate MOSFETs

International Nuclear Information System (INIS)

Jang, Junyong; Lim, Towoo; Kim, Youngmin

2009-01-01

We explore a source/drain (S/D) design for a 16 nm MOSFET utilizing a replacement process for a high-k gate dielectric and metal gate electrode integration. Using TCAD simulation, a trade-off study between series resistance and overlap capacitance is carried out for a high-k dielectric surrounding gate structure, which results from the replacement process. An optimum S/D overlap to gate for the high-k surrounding gate structure is found to be different from the conventional gate structure, i.e. 0∼1 nm underlap is preferred for the surround high-k gate structure while 1∼2 nm overlap for the conventional gate one

Fermi level pinning in metal/Al{sub 2}O{sub 3}/InGaAs gate stack after post metallization annealing

Energy Technology Data Exchange (ETDEWEB)

Winter, R.; Krylov, I.; Cytermann, C.; Eizenberg, M. [Department of Materials Science and Engineering, Technion—Israel Institute of Technology, Haifa 32000 (Israel); Tang, K.; Ahn, J.; McIntyre, P. C. [Department of Materials Science and Engineering, Stanford University, Stanford, California 94305 (United States)

2015-08-07

The effect of post metal deposition annealing on the effective work function in metal/Al{sub 2}O{sub 3}/InGaAs gate stacks was investigated. The effective work functions of different metal gates (Al, Au, and Pt) were measured. Flat band voltage shifts for these and other metals studied suggest that their Fermi levels become pinned after the post-metallization vacuum annealing. Moreover, there is a difference between the measured effective work functions of Al and Pt, and the reported vacuum work function of these metals after annealing. We propose that this phenomenon is caused by charging of indium and gallium induced traps at the annealed metal/Al{sub 2}O{sub 3} interface.

Ultra-fine metal gate operated graphene optical intensity modulator

Science.gov (United States)

Kou, Rai; Hori, Yosuke; Tsuchizawa, Tai; Warabi, Kaori; Kobayashi, Yuzuki; Harada, Yuichi; Hibino, Hiroki; Yamamoto, Tsuyoshi; Nakajima, Hirochika; Yamada, Koji

2016-12-01

A graphene based top-gate optical modulator on a standard silicon photonic platform is proposed for the future optical telecommunication networks. On the basis of the device simulation, we proposed that an electro-absorption light modulation can be realized by an ultra-narrow metal top-gate electrode (width less than 400 nm) directly located on the top of a silicon wire waveguide. The designed structure also provides excellent features such as carrier doping and waveguide-planarization free fabrication processes. In terms of the fabrication, we established transferring of a CVD-grown mono-layer graphene sheet onto a CMOS compatible silicon photonic sample followed by a 25-nm thick ALD-grown Al2O3 deposition and Source-Gate-Drain electrodes formation. In addition, a pair of low-loss spot-size converter for the input and output area is integrated for the efficient light source coupling. The maximum modulation depth of over 30% (1.2 dB) is observed at a device length of 50 μm, and a metal width of 300 nm. The influence of the initial Fermi energy obtained by experiment on the modulation performance is discussed with simulation results.

A refractory metal gate approach for micronic CMOS technology

International Nuclear Information System (INIS)

Lubowiecki, V.; Ledys, J.L.; Plossu, C.; Balland, B.

1987-01-01

In the future, devices scaling down, integration density and performance improvements are going to bring a number of conventional circuit design and process techniques to their fundamental limits. To avoid any severe limitations in MOS ULSI (Ultra Large Scale Integration) technologies, interconnection materials and schemes are required to emerge, in order to face the Megabits memory field. Among those, the gate approach will obviously take a keyrole, when the operating speed of ULSI chips will reach the practical upper limits imposed by parasitic resistances and capacitances which stem from the circuit interconnect wiring. Even if fairly suitable for MOS process, doped polycrystalline silicon is being gradually replaced by refractory metal silicide or polycide structures, which match better with low resistivity requirements. However, as we approach the submicronic IC's, higher conductivity materials will be paid more and more attention. Recently, works have been devoted and published on refractory metal gate technologies. Molybdenum or tungsten, deposited either by CVD or PVD methods, are currently reported even if some drawbacks in their process integration still remain. This paper is willing to present such an approach based on tungsten (more reliable than Molybdenum deposited by LPCVD (giving more conductive and more stable films than PVD). Deposition process will be first described. Then CMOS process flow will allow us to focus on specific refractory metal gate issues. Finally, electrical and physical properties will be assessed, which will demonstrate the feasibility of such a technology as well as the compatibility of the tungsten with most of the usual techniques

CMOS integration of high-k/metal gate transistors in diffusion and gate replacement (D&GR) scheme for dynamic random access memory peripheral circuits

Science.gov (United States)

Dentoni Litta, Eugenio; Ritzenthaler, Romain; Schram, Tom; Spessot, Alessio; O’Sullivan, Barry; Machkaoutsan, Vladimir; Fazan, Pierre; Ji, Yunhyuck; Mannaert, Geert; Lorant, Christophe; Sebaai, Farid; Thiam, Arame; Ercken, Monique; Demuynck, Steven; Horiguchi, Naoto

2018-04-01

Integration of high-k/metal gate stacks in peripheral transistors is a major candidate to ensure continued scaling of dynamic random access memory (DRAM) technology. In this paper, the CMOS integration of diffusion and gate replacement (D&GR) high-k/metal gate stacks is investigated, evaluating four different approaches for the critical patterning step of removing the N-type field effect transistor (NFET) effective work function (eWF) shifter stack from the P-type field effect transistor (PFET) area. The effect of plasma exposure during the patterning step is investigated in detail and found to have a strong impact on threshold voltage tunability. A CMOS integration scheme based on an experimental wet-compatible photoresist is developed and the fulfillment of the main device metrics [equivalent oxide thickness (EOT), eWF, gate leakage current density, on/off currents, short channel control] is demonstrated.

Effect of Thermal Budget on the Electrical Characterization of Atomic Layer Deposited HfSiO/TiN Gate Stack MOSCAP Structure.

Directory of Open Access Journals (Sweden)

Z N Khan

Full Text Available Metal Oxide Semiconductor (MOS capacitors (MOSCAP have been instrumental in making CMOS nano-electronics realized for back-to-back technology nodes. High-k gate stacks including the desirable metal gate processing and its integration into CMOS technology remain an active research area projecting the solution to address the requirements of technology roadmaps. Screening, selection and deposition of high-k gate dielectrics, post-deposition thermal processing, choice of metal gate structure and its post-metal deposition annealing are important parameters to optimize the process and possibly address the energy efficiency of CMOS electronics at nano scales. Atomic layer deposition technique is used throughout this work because of its known deposition kinetics resulting in excellent electrical properties and conformal structure of the device. The dynamics of annealing greatly influence the electrical properties of the gate stack and consequently the reliability of the process as well as manufacturable device. Again, the choice of the annealing technique (migration of thermal flux into the layer, time-temperature cycle and sequence are key parameters influencing the device's output characteristics. This work presents a careful selection of annealing process parameters to provide sufficient thermal budget to Si MOSCAP with atomic layer deposited HfSiO high-k gate dielectric and TiN gate metal. The post-process annealing temperatures in the range of 600°C -1000°C with rapid dwell time provide a better trade-off between the desirable performance of Capacitance-Voltage hysteresis and the leakage current. The defect dynamics is thought to be responsible for the evolution of electrical characteristics in this Si MOSCAP structure specifically designed to tune the trade-off at low frequency for device application.

Rigid muffin-tin approximation for the electron-phonon interaction in transition metals

International Nuclear Information System (INIS)

Butler, W.H.

1980-01-01

Progress in calculating the electron-phonon parameters of transition metals has been based on either the rigid muffin-tin approximation (RMTA) or the fitted modified tight-binding approximation (FMTBA). The RMTA has been shown to be remarkably accurate for average electron-phonon properties, but there are indications that RMTA matrix elements may be too small at low momentum transfer. An attempt is made to demonstrate these assertions concerning the accuracy of RMTA and the numerous electron-phonon calculations are placed in a broader perspective by a demonstration of how they can be used to explain the trends in the strength of the electron-phonon coupling among the transition metals and the A-15 compounds

Rigid muffin-tin approximation for the electron-phonon interaction in transition metals

Energy Technology Data Exchange (ETDEWEB)

Butler, W.H.

1980-01-01

Progress in calculating the electron-phonon parameters of transition metals has been based on either the rigid muffin-tin approximation (RMTA) or the fitted modified tight-binding approximation (FMTBA). The RMTA has been shown to be remarkably accurate for average electron-phonon properties, but there are indications that RMTA matrix elements may be too small at low momentum transfer. An attempt is made to demonstrate these assertions concerning the accuracy of RMTA and the numerous electron-phonon calculations are placed in a broader perspective by a demonstration of how they can be used to explain the trends in the strength of the electron-phonon coupling among the transition metals and the A-15 compounds. (GHT)

Gate metal dependent electrical characteristics of AlGaN/GaN HEMTs

International Nuclear Information System (INIS)

Koo, Sang-Mo; Kang, Min-Seok

2014-01-01

Highlights: • We investigated transfer characteristics of AlGaN/GaN high electron mobility transistors. • We demonstrate the effect of the barrier height of Schottky gate metals. • The conduction mechanisms examine by comparing the experimental results with numerical simulations. • 2-DEG concentration depends on the barrier height of Schottky gate metals. - Abstract: We investigated transfer characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) and the effect of the barrier height of Schottky gate metals. It is found that the threshold voltage of the HEMT structures with the Ni Schottky contact shows a positive shift compared to that of the Ti Schottky contacts (ΔV th = 2.9 V). The maximum saturation current of the HEMT structures with the Ti Schottky contact (∼1.4 × 10 7 A/cm 2 ) is found to be ∼2.5 times higher than that of the Ni Schottky contact (2.9 × 10 7 A/cm 2 ). The conduction mechanisms have been examined by comparing the experimental results with numerical simulations, which confirm that the increased barrier height is mainly attributed to the reduction of 2-DEG concentration

Gate metal dependent electrical characteristics of AlGaN/GaN HEMTs

Energy Technology Data Exchange (ETDEWEB)

Koo, Sang-Mo, E-mail: smkoo@kw.ac.kr; Kang, Min-Seok, E-mail: hyde0220@gmail.com

2014-10-15

Highlights: • We investigated transfer characteristics of AlGaN/GaN high electron mobility transistors. • We demonstrate the effect of the barrier height of Schottky gate metals. • The conduction mechanisms examine by comparing the experimental results with numerical simulations. • 2-DEG concentration depends on the barrier height of Schottky gate metals. - Abstract: We investigated transfer characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) and the effect of the barrier height of Schottky gate metals. It is found that the threshold voltage of the HEMT structures with the Ni Schottky contact shows a positive shift compared to that of the Ti Schottky contacts (ΔV{sub th} = 2.9 V). The maximum saturation current of the HEMT structures with the Ti Schottky contact (∼1.4 × 10{sup 7} A/cm{sup 2}) is found to be ∼2.5 times higher than that of the Ni Schottky contact (2.9 × 10{sup 7} A/cm{sup 2}). The conduction mechanisms have been examined by comparing the experimental results with numerical simulations, which confirm that the increased barrier height is mainly attributed to the reduction of 2-DEG concentration.

Chemistry of tin compounds and environment

International Nuclear Information System (INIS)

Ali, S.; Mazhar, M.; Mahmood, S.; Bhatti, M.H.; Chaudhary, M.A.

1997-01-01

Of the large volume of tin compounds reported in the literature, possible only 100 are commercially important. Tin compounds are a wide variety of purposes such as catalysts, stabilizers for many materials including polymer, biocidal agents, bactericides, insecticides, fungicides, wood preservatives, acaricides and anti fouling agents in paints, anticancer and antitumour agents, ceramic opacifiers, as textile additives, in metal finishing operations, as food additives and in electro conductive coating. All these applications make the environment much exposed to tin contamination. The application of organotin compounds as biocides account for about 30% of total tin consumption suggesting that the main environmental effects are likely to originate from this sector. Diorgano tins and mono-organo tins are used mainly in plastic industry which is the next big source for environmental pollution. In this presentation all environmental aspects of the use of tin compounds and the recommended preventive measures are discussed. (author)

Integration issues of high-k and metal gate into conventional CMOS technology

International Nuclear Information System (INIS)

Song, S.C.; Zhang, Z.; Huffman, C.; Bae, S.H.; Sim, J.H.; Kirsch, P.; Majhi, P.; Moumen, N.; Lee, B.H.

2006-01-01

Issues surrounding the integration of Hf-based high-k dielectrics with metal gates in a conventional CMOS flow are discussed. The careful choice of a gate stack process as well as optimization of other CMOS process steps enables robust CMOSFETs with a wide process latitude. HfO 2 of a 2 nm physical thickness shows complete suppression of transient charge trapping resulting from a significant reduction in film volume as well as kinetically suppressed crystallization. Metal thickness is also critical when optimizing physical stress effects and minimizing dopant diffusion. A high temperature anneal after source and drain implantation in a conventional CMOSFET process reduces the interface state density and improves electron mobility

X-ray radiometric separation of low-grade tin ores

Energy Technology Data Exchange (ETDEWEB)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-10-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. /sup 241/Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained.

X-ray radiometric separation of low-grade tin ores

International Nuclear Information System (INIS)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-01-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. 241 Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained

Feasibility study of using thin aluminum nitride film as a buffer layer for dual metal gate process

International Nuclear Information System (INIS)

Park, Chang Seo; Cho, Byung Jin; Balasubramanian, N.; Kwong, Dim-Lee

2004-01-01

We evaluated the feasibility of using an ultra thin aluminum nitride (AlN) buffer layer for dual metal gates CMOS process. Since the buffer layer should not affect the thickness of gate dielectric, it should be removed or consumed during subsequent process. In this work, it was shown that a thin AlN dielectric layer would be reacted with initial gate metals and would be consumed during subsequent annealing, resulting in no increase of equivalent oxide thickness (EOT). The reaction of AlN layer with tantalum (Ta) and hafnium (Hf) during subsequent annealing, which was confirmed with X-ray photoelectron spectroscopy (XPS) analysis, shifted the flat-band voltage of AlN buffered MOS capacitors. No contribution to equivalent oxide thickness (EOT) was also an indication showing the full consumption of AIN, which was confirmed with TEM analysis. The work functions of gate metals were modulated through the reaction, suggesting that the consumption of AlN resulted in new thin metal alloys. Finally, it was found that the barrier heights of the new alloys were consistent with their work functions

Electrical analysis of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors on flexible bulk mono-crystalline silicon

KAUST Repository

Ghoneim, Mohamed T.; Rojas, Jhonathan Prieto; Young, Chadwin D.; Bersuker, Gennadi; Hussain, Muhammad Mustafa

2015-01-01

We report on the electrical study of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors (MOSCAPs) on a flexible ultra-thin (25 μm) silicon fabric which is peeled off using a CMOS compatible process from a standard

Characterization of tin oxide nanoparticles synthesized via oxidation from metal

International Nuclear Information System (INIS)

Abruzzi, R.C.; Dedavid, B.A.; Pires, M.J.R.; Streicher, M.

2014-01-01

The tin oxide (SnO_2) is a promising material with great potential for applications such as gas sensors and catalysts. This oxide nanostructures show higher activation efficiency due to its larger effective surface. This paper presents the synthesis and characterization of the tin oxide in different conditions, via oxidation of pure tin with nitric acid. Results obtained from the characterization of SnO_2 powder by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX), Particle size by Dynamic Light Scattering (DLS) and Infrared Spectroscopy (FTIR) indicated that the conditions were suitable for the synthesis to obtain manometric tin oxide granules with crystalline structure of rutile. (author)

International strategic minerals inventory summary report; tin

Science.gov (United States)

Sutphin, D.M.; Sabin, A.E.; Reed, B.L.

1990-01-01

The International Strategic Minerals Inventory tin inventory contains records for 56 major tin deposits and districts in 21 countries. These countries accounted for 98 percent of the 10 million metric tons of tin produced in the period 1934-87. Tin is a good alloying metal and is generally nontoxic, and its chief uses are as tinplate for tin cans and as solder in electronics. The 56 locations consist of 39 lode deposits and 17 placers and contain almost 7.5 million metric tons of tin in identified economic resources (R1E) and another 1.5 million metric tons of tin in other resource categories. Most of these resources are in major deposits that have been known for over a hundred years. Lode deposits account for 44 percent of the R1E and 87 percent of the resources in other categories. Placer deposits make up the remainder. Low-income and middle-income countries, including Bolivia and Brazil and countries along the Southeast Asian Tin Belt such as Malaysia, Thailand, and Indonesia account for 91 percent of the R1E resources of tin and for 61 percent of resources in other categories. The United States has less than 0.05 percent of the world's tin R1E in major deposits. Available data suggest that the Soviet Union may have about 4 percent of resources in this category. The industrial market economy countries of the United States, Japan, Federal Republic of Germany, and the United Kingdom are major consumers of tin, whereas the major tin-producing countries generally consume little tin. The Soviet Union and China are both major producers and consumers of tin. At the end of World War II, the four largest tin-producing countries (Bolivia, the Belgian Congo (Zaire), Nigeria, and Malaysia) produced over 80 percent of the world's tin. In 1986, the portion of production from the four largest producers (Malaysia, Brazil, Soviet Union, Indonesia) declined to about 55 percent, while the price of tin rose from about $1,500 to $18,000 per metric ton. In response to tin shortages

Channel length scaling and the impact of metal gate work function ...

Indian Academy of Sciences (India)

As the channel length is reduced from one transistor generation to the next, ... As CMOS technology continues to scale, metal gate electrodes need to be intro .... in the z-direction, q is the electron charge, h is the Planck's constant, Ψ(x, z) is the.

Backside versus frontside advanced chemical analysis of high-k/metal gate stacks

Energy Technology Data Exchange (ETDEWEB)

Martinez, E., E-mail: eugenie.martinez@cea.fr [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Saidi, B. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Veillerot, M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Caubet, P. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Fabbri, J-M. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Piallat, F. [STMicroelectronics, 850 rue Jean Monnet, 38926 Rousset Cedex, Crolles (France); Gassilloud, R. [Univ Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Schamm-Chardon, S. [CEMES-CNRS et Université de Toulouse, 29 rue Jeanne Marvig, 31055 Toulouse (France)

2015-08-15

Highlights: • The backside approach is a promising solution for advanced chemical characterization of future MOSFETs. • Frontside ToF-SIMS and Auger depth profiles are affected by cumulative mixing effects and thus not relevant for analyzing ultra-thin layers. • Higher in-depth resolution is possible in the backside approach for Auger and ToF-SIMS depth profiling. • Backside depth profiling allows revealing ultra-thin layers and elemental in-depth redistribution inside high-k/metal gate stacks. • Backside XPS allows preserving the full metal gate, thus enabling the analysis of real technological samples. - Abstract: Downscaling of transistors beyond the 14 nm technological node requires the implementation of new architectures and materials. Advanced characterization methods are needed to gain information about the chemical composition of buried layers and interfaces. An effective approach based on backside analysis is presented here. X-ray photoelectron spectroscopy, Auger depth profiling and time-of-flight secondary ions mass spectrometry are combined to investigate inter-diffusion phenomena. To highlight improvements related to the backside method, backside and frontside analyses are compared. Critical information regarding nitrogen, oxygen and aluminium redistribution inside the gate stacks is obtained only in the backside configuration.

Nickel-Tin Electrode Materials for Nonaqueous Li-Ion Cells

Science.gov (United States)

Ehrlich, Grant M.; Durand, Christopher

2005-01-01

Experimental materials made from mixtures of nickel and tin powders have shown promise for use as the negative electrodes of rechargeable lithium-ion electrochemical power cells. During charging (or discharging) of a lithium-ion cell, lithium ions are absorbed into (or desorbed from, respectively) the negative electrode, typically through an intercalation or alloying process. The negative electrodes (for this purpose, designated as anodes) in state-of-the-art Li-ion cells are made of graphite, in which intercalation occurs. Alternatively, the anodes can be made from metals, in which alloying can occur. For reasons having to do with the electrochemical potential of intercalated lithium, metallic anode materials (especially materials containing tin) are regarded as safer than graphite ones; in addition, such metallic anode materials have been investigated in the hope of obtaining reversible charge/discharge capacities greater than those of graphite anodes. However, until now, each of the tin-containing metallic anode formulations tested has been found to be inadequate in some respect.

Proton microprobe study of tin-polymetallic deposits

Energy Technology Data Exchange (ETDEWEB)

Murao, S [Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S H; Suter, G F [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1997-12-31

Tin-polymetallic vein type deposits are a complex mixture of cassiterite and sulfides and they are the main source of technologically important rare metals such as indium and bismuth. Constituent minerals are usually fine grained having wide range of chemical composition and often the elements of interest occur as trace elements not amenable to electron microprobe analysis. PIXE with a proton microprobe can be an effective tool to study such deposits by delineating the distribution of trace elements among carrier minerals. Two representative indium-bearing deposits of tin- polymetallic type, Tosham of India (Cu-ln-Bi-Sn-W-Ag), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), were studied to delineate the distribution of medical/high-tech rare metals and to examine the effectiveness of the proton probe analysis of such ore. One of the results of the study indicated that indium and bismuth are present in chalcopyrite in the deposits. In addition to these important rare metals, zinc, copper, arsenic, antimony, selenium, and tin are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are richer in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is related to S-type granite, while Mount Pleasant to A-type. It appears that petrographic character of the source magma is one of the factors to determine the trace element distribution in tin-polymetallic deposit. 6 refs., 2 figs.

Proton microprobe study of tin-polymetallic deposits

Energy Technology Data Exchange (ETDEWEB)

Murao, S. [Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1996-12-31

Tin-polymetallic vein type deposits are a complex mixture of cassiterite and sulfides and they are the main source of technologically important rare metals such as indium and bismuth. Constituent minerals are usually fine grained having wide range of chemical composition and often the elements of interest occur as trace elements not amenable to electron microprobe analysis. PIXE with a proton microprobe can be an effective tool to study such deposits by delineating the distribution of trace elements among carrier minerals. Two representative indium-bearing deposits of tin- polymetallic type, Tosham of India (Cu-ln-Bi-Sn-W-Ag), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), were studied to delineate the distribution of medical/high-tech rare metals and to examine the effectiveness of the proton probe analysis of such ore. One of the results of the study indicated that indium and bismuth are present in chalcopyrite in the deposits. In addition to these important rare metals, zinc, copper, arsenic, antimony, selenium, and tin are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are richer in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is related to S-type granite, while Mount Pleasant to A-type. It appears that petrographic character of the source magma is one of the factors to determine the trace element distribution in tin-polymetallic deposit. 6 refs., 2 figs.

Proton microprobe study of tin-polymetallic deposits

International Nuclear Information System (INIS)

Murao, S.; Sie, S.H.; Suter, G.F.

1996-01-01

Tin-polymetallic vein type deposits are a complex mixture of cassiterite and sulfides and they are the main source of technologically important rare metals such as indium and bismuth. Constituent minerals are usually fine grained having wide range of chemical composition and often the elements of interest occur as trace elements not amenable to electron microprobe analysis. PIXE with a proton microprobe can be an effective tool to study such deposits by delineating the distribution of trace elements among carrier minerals. Two representative indium-bearing deposits of tin- polymetallic type, Tosham of India (Cu-ln-Bi-Sn-W-Ag), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), were studied to delineate the distribution of medical/high-tech rare metals and to examine the effectiveness of the proton probe analysis of such ore. One of the results of the study indicated that indium and bismuth are present in chalcopyrite in the deposits. In addition to these important rare metals, zinc, copper, arsenic, antimony, selenium, and tin are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are richer in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is related to S-type granite, while Mount Pleasant to A-type. It appears that petrographic character of the source magma is one of the factors to determine the trace element distribution in tin-polymetallic deposit. 6 refs., 2 figs

Single-electron-occupation metal-oxide-semiconductor quantum dots formed from efficient poly-silicon gate layout

Energy Technology Data Exchange (ETDEWEB)

Carroll, Malcolm S.; rochette, sophie; Rudolph, Martin; Roy, A. -M.; Curry, Matthew Jon; Ten Eyck, Gregory A.; Manginell, Ronald P.; Wendt, Joel R.; Pluym, Tammy; Carr, Stephen M; Ward, Daniel Robert; Lilly, Michael; pioro-ladriere, michel

2017-07-01

We introduce a silicon metal-oxide-semiconductor quantum dot structure that achieves dot-reservoir tunnel coupling control without a dedicated barrier gate. The elementary structure consists of two accumulation gates separated spatially by a gap, one gate accumulating a reservoir and the other a quantum dot. Control of the tunnel rate between the dot and the reservoir across the gap is demonstrated in the single electron regime by varying the reservoir accumulation gate voltage while compensating with the dot accumulation gate voltage. The method is then applied to a quantum dot connected in series to source and drain reservoirs, enabling transport down to the single electron regime. Finally, tuning of the valley splitting with the dot accumulation gate voltage is observed. This split accumulation gate structure creates silicon quantum dots of similar characteristics to other realizations but with less electrodes, in a single gate stack subtractive fabrication process that is fully compatible with silicon foundry manufacturing.

Flexible semi-transparent silicon (100) fabric with high-k/metal gate devices

KAUST Repository

Rojas, Jhonathan Prieto

2013-01-07

Can we build a flexible and transparent truly high performance computer? High-k/metal gate stack based metal-oxide-semiconductor capacitor devices are monolithically fabricated on industry\\'s most widely used low-cost bulk single-crystalline silicon (100) wafers and then released as continuous, mechanically flexible, optically semi-transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree of freedom to fabricate nanoelectronics devices using state-of-the-art CMOS compatible processes and then to utilize them in an unprecedented way for wide deployment over nearly any kind of shape and architecture surfaces. Electrical characterization shows uncompromising performance of post release devices. Mechanical characterization shows extra-ordinary flexibility (minimum bending radius of 1 cm) making this generic process attractive to extend the horizon of flexible electronics for truly high performance computers. Schematic and photograph of flexible high-k/metal gate MOSCAPs showing high flexibility and C-V plot showing uncompromised performance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of tin, chromium, cadmium and lead in canned fruits from the Czech market

Directory of Open Access Journals (Sweden)

Pavel Diviš

2017-01-01

Full Text Available The global production of metal cans is more than 300 billion cans. Benefits of metal packaging consist mainly from the great strenght, excellent barrier properties and good thermal conductivity. The main problem of used metal packaging are the corrosion processes. The corrosion of metal container causes dissolution of tin which is used as a protective layer of the steel shell of the can and other metallic elements used in the manufacture of cans. In this work 31 samples of canned fruit was analysed and the concentration of tin, chromium, cadmium and lead was determined in fruit and in syrup using ICP-OES and ICP-MS techniques. The results showed no difference between the concentration of analysed elements in fruit and in syrup. In none of the analyzed samples the permitted maximum concentration of tin 200 mg.kg-1 was exceeded. Maximum concentration of tin was measured in canned grepfruit (59.8 ±1.9 mg.kg-1. The age of cans had no significant effect on the concentration of tin in canned fruit. The concentration of tin in fruit packaged in cans with protective layer of lacquer was significantly lower than the concentration of tin in fruit packaged in cans without protective layer of lacquer. Concentration of chromium, cadmium and lead in the analysed samples was very low at the natural levels of occurrence of these metals in fruit and it was impossible to determine unequivocally that the measured concentrations of these metals in canned fruit originate from the corrosion of can. The corrosion of the tinplate was studied using scanning electron microscopy with an energy dispersive spectrometer. By analyzing the SEM pictures and EDS spectra, critical areas of tin plate corrosion were observed. Based on the measured results it can be concluded that the consumption of fresh canned fruit is not a major problem for the inhabitants of the Czech Republic in terms of intake of potentially hazardous metals.

Impact of metal-ion contaminated silica particles on gate oxide integrity

NARCIS (Netherlands)

Rink, Ingrid; Wali, F.; Knotter, D.M.

2009-01-01

The impact of metal-ion contamination (present on wafer surface before oxidation) on gate oxide integrity (GOI) is well known in literature, which is not the case for clean silica particles [1, 2]. However, it is known that particles present in ultra-pure water (UPW) decrease the random yield in

Bismuth-, Tin-, and Lead-Containing Metal-Organic Materials: Synthesis, Structure, Photoluminescence, Second Harmonic Generation, and Ferroelectric Properties

Science.gov (United States)

Wibowo, Arief Cahyo

Metal-Organic Materials (MOMs) contain metal moieties and organic ligands that combine to form discrete (e.g. metal-organic polyhedra, spheres or nanoballs, metal-organic polygons) or polymeric structures with one-, two-, or three-dimensional periodicities that can exhibit a variety of properties resulting from the presence of the metal moieties and/or ligand connectors in the structure. To date, MOMs with a range of functional attributes have been prepared, including record-breaking porosity, catalytic properties, molecular magnetism, chemical separations and sensing ability, luminescence and NLO properties, multiferroic, ferroelectric, and switchable molecular dielectric properties. We are interested in synthesizing non-centrosymmetric MOM single crystals possessing one of the ten polar space groups required for non-linear optical properties (such as second harmonic generation) and ferroelectric applications. This thesis is divided into two main parts: materials with optical properties, such as photoluminescence and materials for targeted applications such as second harmonic generation and ferroelectric properties. This thesis starts with an introduction describing material having centrosymmetric, non-polar space groups, single crystals structures and their photoluminescence properties. These crystals exhibit very interesting and rare structures as well as interesting photoluminescence properties. Chapters 2-5 of this thesis focus on photoluminescent properties of new MOMs, and detail the exploratory research involving the comparatively rare bismuth, lead, and tin coordination polymers. Specifically, the formation of single white-light emitting phosphors based on the combination of bismuth or lead with pyridine-2,5-dicarboxylate is discussed (Chapter 2). The observation of a new Bi2O2 layer and a new Bi4O 3 chain in bismuth terephthalate-based coordination polymers is presented in Chapter 3, while the formation of diverse structures of tin-based coordination

Channel length scaling and the impact of metal gate work function ...

Indian Academy of Sciences (India)

Further- more, quantum effects on the performance of DG-MOSFETs are addressed and discussed. We also study the influence of metal gate work function on the performance of nanoscale MOSFETs. We use a self-consistent Poisson–Schrödinger solver in two dimensions over the entire device. A good agreement with ...

The mechanism of diffusion and ionic transport of alkali metal ions in the particles of tin(IV) antimonate

International Nuclear Information System (INIS)

El-Naggar, I.M.; El-Absy, M.A.; Aly, S.I.; Atomic Energy Establishment, Cairo

1992-01-01

The kinetics of exchange Li + , Na + , K + and Cs + ions of tin(IV) antimonate with H + form was studied under particle-diffusion-control conditions at different temperatures. The value of activation energy, diffusion coefficient and entropy of activation increase with the ionic mobilities and radii, and decrease with the hydration energy of the alkali metal ions. On the basis of the kinetic parameters, the exchange of alkali metal ions occurs in the unhydrated form. (author). 29 refs.; 4 figs.; 2 tabs

Electrochemical migration of tin in electronics and microstructure of the dendrites

Energy Technology Data Exchange (ETDEWEB)

Minzari, Daniel, E-mail: dmin@mek.dtu.d [Section for Materials and Surface Technology, Department for Mechanical Engineering, Technical University of Denmark (Denmark); Grumsen, Flemming Bjerg; Jellesen, Morten S.; Moller, Per; Ambat, Rajan [Section for Materials and Surface Technology, Department for Mechanical Engineering, Technical University of Denmark (Denmark)

2011-05-15

Graphical abstract: The electrochemical migration of tin in electronics forms dendritic structures, consisting of a metallic tin core, which is surrounded by oxide layers having various thickness. Display Omitted Research highlights: Electrochemical migration occurs if two conductors are connected by condensed moisture. Metallic ions are dissolved and grow in a dendritic structure that short circuit the electrodes. The dendrite consists of a metallic tin core with oxide layers of various thickness surrounding. Detailed microstructure of dendrites is investigated using electron microscopy. The dendrite microstructure is heterogeneous along the growth direction. - Abstract: The macro-, micro-, and nano-scale morphology and structure of tin dendrites, formed by electrochemical migration on a surface mount ceramic chip resistor having electrodes consisting of tin with small amounts of Pb ({approx}2 wt.%) was investigated by scanning electron microscopy and transmission electron microscopy including Energy dispersive X-ray spectroscopy and electron diffraction. The tin dendrites were formed under 5 or 12 V potential bias in 10 ppm by weight NaCl electrolyte as a micro-droplet on the resistor during electrochemical migration experiments. The dendrites formed were found to have heterogeneous microstructure along the growth direction, which is attributed to unstable growth conditions inside the micro-volume of electrolyte. Selected area electron diffraction showed that the dendrites are metallic tin having sections of single crystal orientation and lead containing intermetallic particles embedded in the structure. At certain areas, the dendrite structure was found to be surrounded by an oxide crust, which is believed to be due to unstable growth conditions during the dendrite formation. The oxide layer was found to be of nanocrystalline structure, which is expected to be formed by the dehydration of the hydrated oxide originally formed in solution ex-situ in ambient air.

Hydrogen ion sensors based on indium tin oxide thin film using radio frequency sputtering system

International Nuclear Information System (INIS)

Chiang, Jung-Lung; Jhan, Syun-Sheng; Hsieh, Shu-Chen; Huang, An-Li

2009-01-01

Indium tin oxide (ITO) thin films were deposited onto Si and SiO 2 /Si substrates using a radio frequency sputtering system with a grain size of 30-50 nm and thickness of 270-280 nm. ITO/Si and ITO/SiO 2 /Si sensing structures were achieved and connected to a standard metal-oxide-semiconductor field-effect transistor (MOSFET) as an ITO pH extended-gate field-effect transistor (ITO pH-EGFET). The semiconductor parameter analysis measurement (Keithley 4200) was utilized to measure the current-voltage (I-V) characteristics curves and study the sensing properties of the ITO pH-EGFET. The linear pH voltage sensitivities were about 41.43 and 43.04 mV/pH for the ITO/Si and ITO/SiO 2 /Si sensing structures, respectively. At the same time, both pH current sensitivities were about 49.86 and 51.73 μA/pH, respectively. Consequently, both sensing structures can be applied as extended-gate sensing heads. The separative structure is suitable for application as a disposable pH sensor.

Magnetic phase transition induced by electrostatic gating in two-dimensional square metal-organic frameworks

Science.gov (United States)

Wang, Yun-Peng; Li, Xiang-Guo; Liu, Shuang-Long; Fry, James N.; Cheng, Hai-Ping

2018-03-01

We investigate theoretically magnetism and magnetic phase transitions induced by electrostatic gating of two-dimensional square metal-organic framework compounds. We find that electrostatic gating can induce phase transitions between homogeneous ferromagnetic and various spin-textured antiferromagnetic states. Electronic structure and Wannier function analysis can reveal hybridizations between transition-metal d orbitals and conjugated π orbitals in the organic framework. Mn-containing compounds exhibit a strong d -π hybridization that leads to partially occupied spin-minority bands, in contrast to compounds containing transition-metal ions other than Mn, for which electronic structure around the Fermi energy is only slightly spin split due to weak d -π hybridization and the magnetic interaction is of the Ruderman-Kittel-Kasuya-Yosida type. We use a ferromagnetic Kondo lattice model to understand the phase transition in Mn-containing compounds in terms of carrier density and illuminate the complexity and the potential to control two-dimensional magnetization.

Studies on the surface modification of TiN coatings using MEVVA ion implantation with selected metallic species

International Nuclear Information System (INIS)

Ward, L.P.; Purushotham, K.P.; Manory, R.R.

2016-01-01

Highlights: • Reduced surface roughness was observed after ion implantation. • W implantation increased residual stress. • Reduced friction and wear accompanied Mo implantation. • Mo implanted layer was more resistant to breakdown during wear testing. • Ion implantation effects can be complex on various implanting species properties. - Abstract: Improvement in the performance of TiN coatings can be achieved using surface modification techniques such as ion implantation. In the present study, physical vapor deposited (PVD) TiN coatings were implanted with Cr, Zr, Nb, Mo and W using the metal evaporation vacuum arc (MEVVA) technique at a constant nominal dose of 4 × 10 16 ions cm −2 for all species. The samples were characterized before and after implantation, using Rutherford backscattering (RBS), glancing incident angle X-ray diffraction (GIXRD), atomic force microscopy (AFM) and optical microscopy. Friction and wear studies were performed under dry sliding conditions using a pin-on-disc CSEM Tribometer at 1 N load and 450 m sliding distance. A reduction in the grain size and surface roughness was observed after implantation with all five species. Little variation was observed in the residual stress values for all implanted TiN coatings, except for W implanted TiN which showed a pronounced increase in compressive residual stress. Mo-implanted samples showed a lower coefficient of friction and higher resistance to breakdown during the initial stages of testing than as-received samples. Significant reduction in wear rate was observed after implanting with Zr and Mo ions compared with unimplanted TiN. The presence of the Ti 2 N phase was observed with Cr implantation.

Effect of oxygen on tuning the TiNx metal gate work function on LaLuO3

International Nuclear Information System (INIS)

Mitrovic, I.Z.; Przewlocki, H.M.; Piskorski, K.; Simutis, G.; Dhanak, V.R.; Sedghi, N.; Hall, S.

2012-01-01

This paper presents experimental evidence on effective work function tuning due to the presence of oxygen at the TiNx/LaLuO 3 interface. Two complementary techniques, internal photoemission and X-ray photoelectron spectroscopy, show good agreement on the position of the metal gate Fermi level to conduction (2.79 ± 0.25 eV) and valence (2.65 ± 0.08 eV) band edge for TiNx/bulk LaLuO 3 gate stacks. The chemical shifts of Ti2p and N1s core levels and different degree in ionicity of TiNx metal gates correlate with the observed valence band offset shifts. The results have significance for setting the band edge work function and resulting low threshold voltage for ultimately scaled LaLuO 3 -based p-metal oxide semiconductor field effect transistor devices. - Highlights: ► The conduction band offset measured by internal photoemission. ► The valence band offset (VBO) measured by X-ray photoelectron spectroscopy. ► Different degree in ionicity of TiNx correlates with the VBO shifts. ► The effective work function of the gate stacks varies from 4.6 to 5.2 eV. ► Oxygen at the TiNx/LaLuO 3 interface increases effective work function.

Semiconductor to metallic transition in bulk accumulated amorphous indium-gallium-zinc-oxide dual gate thin-film transistor

Directory of Open Access Journals (Sweden)

Minkyu Chun

2015-05-01

Full Text Available We investigated the effects of top gate voltage (VTG and temperature (in the range of 25 to 70 oC on dual-gate (DG back-channel-etched (BCE amorphous-indium-gallium-zinc-oxide (a-IGZO thin film transistors (TFTs characteristics. The increment of VTG from -20V to +20V, decreases the threshold voltage (VTH from 19.6V to 3.8V and increases the electron density to 8.8 x 1018cm−3. Temperature dependent field-effect mobility in saturation regime, extracted from bottom gate sweep, show a critical dependency on VTG. At VTG of 20V, the mobility decreases from 19.1 to 15.4 cm2/V ⋅ s with increasing temperature, showing a metallic conduction. On the other hand, at VTG of - 20V, the mobility increases from 6.4 to 7.5cm2/V ⋅ s with increasing temperature. Since the top gate bias controls the position of Fermi level, the temperature dependent mobility shows metallic conduction when the Fermi level is above the conduction band edge, by applying high positive bias to the top gate.

NASA Goddard Space Flight Center Tin Whisker (and Other Metal Whisker) Homepage

Science.gov (United States)

Brusse, Jay; Sampson, Mike; Leidecker, Henning; Kadesch, Jong

2004-01-01

This website provides information about tin whiskers and related research. The independent research performed during the past 50+ years is so vast that it is impractical to cover all aspects of tin whiskers in this one resource. Therefore, the absence of information in this website about a particular aspect of tin whiskers should NOT be construed as evidence of absence.

Electron-electron scattering-induced channel hot electron injection in nanoscale n-channel metal-oxide-semiconductor field-effect-transistors with high-k/metal gate stacks

International Nuclear Information System (INIS)

Tsai, Jyun-Yu; Liu, Kuan-Ju; Lu, Ying-Hsin; Liu, Xi-Wen; Chang, Ting-Chang; Chen, Ching-En; Ho, Szu-Han; Tseng, Tseung-Yuen; Cheng, Osbert; Huang, Cheng-Tung; Lu, Ching-Sen

2014-01-01

This work investigates electron-electron scattering (EES)-induced channel hot electron (CHE) injection in nanoscale n-channel metal-oxide-semiconductor field-effect-transistors (n-MOSFETs) with high-k/metal gate stacks. Many groups have proposed new models (i.e., single-particle and multiple-particle process) to well explain the hot carrier degradation in nanoscale devices and all mechanisms focused on Si-H bond dissociation at the Si/SiO 2 interface. However, for high-k dielectric devices, experiment results show that the channel hot carrier trapping in the pre-existing high-k bulk defects is the main degradation mechanism. Therefore, we propose a model of EES-induced CHE injection to illustrate the trapping-dominant mechanism in nanoscale n-MOSFETs with high-k/metal gate stacks.

Coating of metals

International Nuclear Information System (INIS)

Smith, F.

1978-01-01

A method is described for coating the surface of an article of Ti, Zr or Ta, or an alloy thereof, with a tinning metal or alloy, the article having a shape other than that of a sheet. The method comprises contacting the surface of the article at an elevated temperature with the molten tinning metal and moving an ultrasonically excited probe over the surface to be coated, the probe being in contact with the surface of the article and with the tinning metal. The tinning metal may be Sn or Zn or a binary alloy of Sn with Zn, Cd or Bi at a temperature of 300 0 to 450 0 C. The head of the probe may be shaped to conform with the surface of the article. The method may be used to form composite articles, and may be applied to a pre-tinned steel article. (U.K.)

Surface Preparation and Deposited Gate Oxides for Gallium Nitride Based Metal Oxide Semiconductor Devices

Directory of Open Access Journals (Sweden)

Paul C. McIntyre

2012-07-01

Full Text Available The literature on polar Gallium Nitride (GaN surfaces, surface treatments and gate dielectrics relevant to metal oxide semiconductor devices is reviewed. The significance of the GaN growth technique and growth parameters on the properties of GaN epilayers, the ability to modify GaN surface properties using in situ and ex situ processes and progress on the understanding and performance of GaN metal oxide semiconductor (MOS devices are presented and discussed. Although a reasonably consistent picture is emerging from focused studies on issues covered in each of these topics, future research can achieve a better understanding of the critical oxide-semiconductor interface by probing the connections between these topics. The challenges in analyzing defect concentrations and energies in GaN MOS gate stacks are discussed. Promising gate dielectric deposition techniques such as atomic layer deposition, which is already accepted by the semiconductor industry for silicon CMOS device fabrication, coupled with more advanced physical and electrical characterization methods will likely accelerate the pace of learning required to develop future GaN-based MOS technology.

Anomalous positive flatband voltage shifts in metal gate stacks containing rare-earth oxide capping layers

KAUST Repository

Caraveo-Frescas, J. A.

2012-03-09

It is shown that the well-known negative flatband voltage (VFB) shift, induced by rare-earth oxide capping in metal gate stacks, can be completely reversed in the absence of the silicon overlayer. Using TaN metal gates and Gd2O3-doped dielectric, we measure a ∼350 mV negative shift with the Si overlayer present and a ∼110 mV positive shift with the Si overlayer removed. This effect is correlated to a positive change in the average electrostatic potential at the TaN/dielectric interface which originates from an interfacial dipole. The dipole is created by the replacement of interfacial oxygen atoms in the HfO2 lattice with nitrogen atoms from TaN.

Semiconductor to metallic transition in bulk accumulated amorphous indium-gallium-zinc-oxide dual gate thin-film transistor

Energy Technology Data Exchange (ETDEWEB)

Chun, Minkyu; Chowdhury, Md Delwar Hossain; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center and Department of Information Display, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

2015-05-15

We investigated the effects of top gate voltage (V{sub TG}) and temperature (in the range of 25 to 70 {sup o}C) on dual-gate (DG) back-channel-etched (BCE) amorphous-indium-gallium-zinc-oxide (a-IGZO) thin film transistors (TFTs) characteristics. The increment of V{sub TG} from -20V to +20V, decreases the threshold voltage (V{sub TH}) from 19.6V to 3.8V and increases the electron density to 8.8 x 10{sup 18}cm{sup −3}. Temperature dependent field-effect mobility in saturation regime, extracted from bottom gate sweep, show a critical dependency on V{sub TG}. At V{sub TG} of 20V, the mobility decreases from 19.1 to 15.4 cm{sup 2}/V ⋅ s with increasing temperature, showing a metallic conduction. On the other hand, at V{sub TG} of - 20V, the mobility increases from 6.4 to 7.5cm{sup 2}/V ⋅ s with increasing temperature. Since the top gate bias controls the position of Fermi level, the temperature dependent mobility shows metallic conduction when the Fermi level is above the conduction band edge, by applying high positive bias to the top gate.

IMPROVEMENT OF FATIGUE STRENGTH OF TIN BABBITT BY REINFORCING WITH NANO ILMENITE

Directory of Open Access Journals (Sweden)

M. V. S. BABU

2017-08-01

Full Text Available Tin Babbitt is an idle journal bearing material, its fatigue strength limits and its usage. To enhance its fatigue strength, in this paper a Tin Babbitt metal matrix is reinforced with nano Ilmenite. The metal matrix nanocomposite was fabricated by using ultrasonic assisted stir casting technique. ASTM standards in statistical planning for fatigue testing were employed in planning the fatigue tests. Fatigue tests were conducted at three stress levels, i.e., 0.9 UTS, 0.7 UTS and 0.5 UTS. Tests were conducted on a rotating-beam type fatigue testing machine. It was observed that the nano Ilmenite reinforcement enhanced the fatigue strength of Tin Babbitt.

Pseudo 2-transistor active pixel sensor using an n-well/gate-tied p-channel metal oxide semiconductor field eeffect transistor-type photodetector with built-in transfer gate

Science.gov (United States)

Seo, Sang-Ho; Seo, Min-Woong; Kong, Jae-Sung; Shin, Jang-Kyoo; Choi, Pyung

2008-11-01

In this paper, a pseudo 2-transistor active pixel sensor (APS) has been designed and fabricated by using an n-well/gate-tied p-channel metal oxide semiconductor field effect transistor (PMOSFET)-type photodetector with built-in transfer gate. The proposed sensor has been fabricated using a 0.35 μm 2-poly 4-metal standard complementary metal oxide semiconductor (CMOS) logic process. The pseudo 2-transistor APS consists of two NMOSFETs and one photodetector which can amplify the generated photocurrent. The area of the pseudo 2-transistor APS is 7.1 × 6.2 μm2. The sensitivity of the proposed pixel is 49 lux/(V·s). By using this pixel, a smaller pixel area and a higher level of sensitivity can be realized when compared with a conventional 3-transistor APS which uses a pn junction photodiode.

Electronic Properties of Tin and Bismuth from Angular Correlation of Annihilation Photons

DEFF Research Database (Denmark)

Mogensen, O.E.; Trumpy, Georg

1969-01-01

) deformed bismuth. For both metals, the single-crystal angular-correlation curves lie near to the free-electron parabola. The tin curves show more anisotropy than the bismuth curves. An important result is the clear anisotropy found in the high-momentum part of the curves—the tails—for both metals. Little......A linear slit setup has been used to obtain results of angular-correlation measurements in (a) tin single crystals in three orientations: [001], [100], and [110], (b) bismuth single crystals in four orientations: [111], [100], [1¯10], and [2¯1¯1], (c) solid and liquid tin and bismuth, and (d...... of the liquid-metal curves are smaller and of another form than the tails of polycrystalline curves; no Gaussian with only one adjustable constant factor can give a fit to both tails. No useful method for interpreting liquid-metal angular-correlation curves seems to exist. Two deformed bismuth samples gave...

Investigation of High-k Dielectrics and Metal Gate Electrodes for Non-volatile Memory Applications

Science.gov (United States)

Jayanti, Srikant

Due to the increasing demand of non-volatile flash memories in the portable electronics, the device structures need to be scaled down drastically. However, the scalability of traditional floating gate structures beyond 20 nm NAND flash technology node is uncertain. In this regard, the use of metal gates and high-k dielectrics as the gate and interpoly dielectrics respectively, seem to be promising substitutes in order to continue the flash scaling beyond 20nm. Furthermore, research of novel memory structures to overcome the scaling challenges need to be explored. Through this work, the use of high-k dielectrics as IPDs in a memory structure has been studied. For this purpose, IPD process optimization and barrier engineering were explored to determine and improve the memory performance. Specifically, the concept of high-k / low-k barrier engineering was studied in corroboration with simulations. In addition, a novel memory structure comprising a continuous metal floating gate was investigated in combination with high-k blocking oxides. Integration of thin metal FGs and high-k dielectrics into a dual floating gate memory structure to result in both volatile and non-volatile modes of operation has been demonstrated, for plausible application in future unified memory architectures. The electrical characterization was performed on simple MIS/MIM and memory capacitors, fabricated through CMOS compatible processes. Various analytical characterization techniques were done to gain more insight into the material behavior of the layers in the device structure. In the first part of this study, interfacial engineering was investigated by exploring La2O3 as SiO2 scavenging layer. Through the silicate formation, the consumption of low-k SiO2 was controlled and resulted in a significant improvement in dielectric leakage. The performance improvement was also gauged through memory capacitors. In the second part of the study, a novel memory structure consisting of continuous metal FG

Removal of heavy metals from metal-containing effluent by yeast ...

African Journals Online (AJOL)

Removal of heavy metals from metal-containing effluent by yeast biomass. ... Research studies have described this phenomenon of fast initial sorption with a ... chrome and tin from the chrome and tin effluents of a local iron and steel industry.

Recovery Of Valuable Metals In Tin-Based Anodic Slimes By Carbothermic Reaction

OpenAIRE

Han Chulwoong; Kim Young-Min; Son Seong Ho; Choi Hanshin; Kim Tae Bum; Kim Yong Hwan

2015-01-01

This study investigated the recovery of anodic slimes by carbothermic reaction in the temperature range of 973~1,273K and amount of carbon as a function of time. Tin anodic slime samples were collected from the bottom of the electrolytic cells during the electro-refining of tin. The anodic slimes are consisted of high concentrated tin, silver, copper and lead oxides. The kinetics of reduction were determined by means of the weight-loss measurement technique. In order to understand in detail o...

Gate Engineering in SOI LDMOS for Device Reliability

Directory of Open Access Journals (Sweden)

Aanand

2016-01-01

Full Text Available A linearly graded doping drift region with step gate structure, used for improvement of reduced surface field (RESURF SOI LDMOS transistor performance has been simulated with 0.35µm technology in this paper. The proposed device has one poly gate and double metal gate arranged in a stepped manner, from channel to drift region. The first gate uses n+ poly (near source where as other two gates of aluminium. The first gate with thin gate oxide has good control over the channel charge. The third gate with thick gate oxide at drift region reduce gate to drain capacitance. The arrangement of second and third gates in a stepped manner in drift region spreads the electric field uniformly. Using two dimensional device simulations, the proposed SOI LDMOS is compared with conventional structure and the extended metal structure. We demonstrate that the proposed device exhibits significant enhancement in linearity, breakdown voltage, on-resistance and HCI. Double metal gate reduces the impact ionization area which helps to improve the Hot Carrier Injection effect..

Synthesis of antimony-doped tin oxide (ATO) nanoparticles by the nitrate-citrate combustion method

International Nuclear Information System (INIS)

Zhang Jianrong; Gao Lian

2004-01-01

Antimony-doped tin oxide (ATO) nanoparticles having rutile structure have been synthesized by the combustion method using citric acid (CA) as fuel and nitrate as an oxidant, the metal sources were granulated tin and Sb 2 O 3 . The influence of citric acid (fuel) to metal ratio on the average crystallite size, specific surface area and morphology of the nanoparticles has been investigated. X-ray diffraction showed the tin ions were reduced to elemental tin during combustion reaction. The average ATO crystallite size increased with the increase of citric acid (fuel). Powder morphology and the comparison of crystallite size and grain size shows that the degree of agglomeration of the powder decreased with an increase of the ratio. The highest specific surface area was 37.5 m 2 /g when the citric acid to tin ratio was about 6

Atomic-Layer-Deposited SnO2 as Gate Electrode for Indium-Free Transparent Electronics

KAUST Repository

Alshammari, Fwzah Hamud

2017-08-04

Atomic-layer-deposited SnO2 is used as a gate electrode to replace indium tin oxide (ITO) in thin-film transistors and circuits for the first time. The SnO2 films deposited at 200 °C show low electrical resistivity of ≈3.1 × 10−3 Ω cm with ≈93% transparency in most of the visible range of the electromagnetic spectrum. Thin-film transistors fabricated with SnO2 gates show excellent transistor properties including saturation mobility of 15.3 cm2 V−1 s−1, a low subthreshold swing of ≈130 mV dec−1, a high on/off ratio of ≈109, and an excellent electrical stability under constant-voltage stressing conditions to the gate terminal. Moreover, the SnO2-gated thin-film transistors show excellent electrical characteristics when used in electronic circuits such as negative channel metal oxide semiconductor (NMOS) inverters and ring oscillators. The NMOS inverters exhibit a low propagation stage delay of ≈150 ns with high DC voltage gain of ≈382. A high oscillation frequency of ≈303 kHz is obtained from the output sinusoidal signal of the 11-stage NMOS inverter-based ring oscillators. These results show that SnO2 can effectively replace ITO in transparent electronics and sensor applications.

Anomalous growth of whisker-like bismuth-tin extrusions from tin-enriched tin-Bi deposits

International Nuclear Information System (INIS)

Hu, C.-C.; Tsai, Y.-D.; Lin, C.-C.; Lee, G.-L.; Chen, S.-W.; Lee, T.-C.; Wen, T.-C.

2009-01-01

This article shows the first finding that the anomalous growth of Bi-Sn extrusions from tin-enriched alloys (Sn-xBi with x between 20 and 10 wt.%) can be induced by post-plating annealing in N 2 between 145 and 260 deg. C for 10 min although metal whiskers were commonly formed on the surface of pure metals or alloys of the enriched component. From SEM observations, very similar to Sn whiskers, Bi-Sn extrusions vary in size, shape, length, and diameter with changing the annealing temperature, which are highly important in regarding the potential for failure of electronic products. Annealing resulting in thermal expansion of Sn grains is believed to squeeze the Bi-Sn alloys with relatively low melting points to form whisker-like extrusions although the exact mechanism is unclear

Intermodulation Linearity in High-k/Metal Gate 28 nm RF CMOS Transistors

Directory of Open Access Journals (Sweden)

Zhen Li

2015-09-01

Full Text Available This paper presents experimental characterization, simulation, and Volterra series based analysis of intermodulation linearity on a high-k/metal gate 28 nm RF CMOS technology. A figure-of-merit is proposed to account for both VGS and VDS nonlinearity, and extracted from frequency dependence of measured IIP3. Implications to biasing current and voltage optimization for linearity are discussed.

Cyclic voltammetric study of tin hexacyanoferrate for aqueous battery applications

Directory of Open Access Journals (Sweden)

Denys Gromadskyi

2016-09-01

Full Text Available A hybrid composite containing 65 mass % of tin hexacyanoferrate mixed with 35 mass % of carbon nanotubes has been synthesized and its electrochemical behavior as a negative electrode in alkali metal-ion batteries has been studied in 1 mol L-1 aqueous solution of sodium sulfate. The specific capacity of pure tin hexacyanoferrate is 58 mAh g-1, whereas the specific capacity normalized per total electrode mass of the composite studied reaches 34 mAh g-1. The estimated maximal specific power of an aqueous alkali-metal ion battery with a tin hexacyanoferrate electrode is ca. 3.6 kW kg-1 being comparable to characteristics of industrial electric double-layer capacitors. The maximal specific energy accumulated by this battery may reach 25.6 Wh kg-1 at least three times exceeding the specific energy for supercapacitors.

Low band-to-band tunnelling and gate tunnelling current in novel nanoscale double-gate architecture: simulations and investigation

International Nuclear Information System (INIS)

Datta, Deepanjan; Ganguly, Samiran; Dasgupta, S

2007-01-01

Large band-to-band tunnelling (BTBT) and gate leakage current can limit scalability of nanoscale devices. In this paper, we have proposed a novel nanoscale parallel connected heteromaterial double gate (PCHEM-DG) architecture with triple metal gate which significantly suppress BTBT leakage, making it efficient for low power design in the sub-10 nm regime. We have also proposed a triple gate device with p + poly-n + poly-p + poly gate which has substantially low gate leakage over symmetric DG MOSFET. Simulations are performed using a 2D Poisson-Schroedinger simulator and verified with a 2D device simulator ATLAS. We conclude that, due to intrinsic body doping, negligible gate leakage, suppressed BTBT over symmetric DG devices, metal gate (MG) PCHEM-DG MOSFET is efficient for low power circuit design in the nanometre regime

All-metallic electrically gated 2H-TaSe2 thin-film switches and logic circuits

International Nuclear Information System (INIS)

Renteria, J.; Jiang, C.; Yan, Z.; Samnakay, R.; Goli, P.; Pope, T. R.; Salguero, T. T.; Wickramaratne, D.; Lake, R. K.; Khitun, A. G.; Balandin, A. A.

2014-01-01

We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe 2 were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe 2 –Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials

All-metallic electrically gated 2H-TaSe2 thin-film switches and logic circuits

Science.gov (United States)

Renteria, J.; Samnakay, R.; Jiang, C.; Pope, T. R.; Goli, P.; Yan, Z.; Wickramaratne, D.; Salguero, T. T.; Khitun, A. G.; Lake, R. K.; Balandin, A. A.

2014-01-01

We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe2 were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe2-Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials.

Low band-to-band tunnelling and gate tunnelling current in novel nanoscale double-gate architecture: simulations and investigation

Energy Technology Data Exchange (ETDEWEB)

Datta, Deepanjan [Department of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47906 (United States); Ganguly, Samiran [Department of Electronics Engineering, Indian School of Mines, Dhanbad-826004 (India); Dasgupta, S [Department of Electronics and Computer Engineering, Indian Institute of Technology, Roorkee-247667 (India)

2007-05-30

Large band-to-band tunnelling (BTBT) and gate leakage current can limit scalability of nanoscale devices. In this paper, we have proposed a novel nanoscale parallel connected heteromaterial double gate (PCHEM-DG) architecture with triple metal gate which significantly suppress BTBT leakage, making it efficient for low power design in the sub-10 nm regime. We have also proposed a triple gate device with p{sup +} poly-n{sup +} poly-p{sup +} poly gate which has substantially low gate leakage over symmetric DG MOSFET. Simulations are performed using a 2D Poisson-Schroedinger simulator and verified with a 2D device simulator ATLAS. We conclude that, due to intrinsic body doping, negligible gate leakage, suppressed BTBT over symmetric DG devices, metal gate (MG) PCHEM-DG MOSFET is efficient for low power circuit design in the nanometre regime.

Investigation of Rapid Low-Power Microwave-Induction Heating Scheme on the Cross-Linking Process of the Poly(4-vinylphenol) for the Gate Insulator of Pentacene-Based Thin-Film Transistors

Science.gov (United States)

Fan, Ching-Lin; Shang, Ming-Chi; Wang, Shea-Jue; Hsia, Mao-Yuan; Lee, Win-Der; Huang, Bohr-Ran

2017-01-01

In this study, a proposed Microwave-Induction Heating (MIH) scheme has been systematically studied to acquire suitable MIH parameters including chamber pressure, microwave power and heating time. The proposed MIH means that the thin indium tin oxide (ITO) metal below the Poly(4-vinylphenol) (PVP) film is heated rapidly by microwave irradiation and the heated ITO metal gate can heat the PVP gate insulator, resulting in PVP cross-linking. It is found that the attenuation of the microwave energy decreases with the decreasing chamber pressure. The optimal conditions are a power of 50 W, a heating time of 5 min, and a chamber pressure of 20 mTorr. When suitable MIH parameters were used, the effect of PVP cross-linking and the device performance were similar to those obtained using traditional oven heating, even though the cross-linking time was significantly decreased from 1 h to 5 min. Besides the gate leakage current, the interface trap state density (Nit) was also calculated to describe the interface status between the gate insulator and the active layer. The lowest interface trap state density can be found in the device with the PVP gate insulator cross-linked by using the optimal MIH condition. Therefore, it is believed that the MIH scheme is a good candidate to cross-link the PVP gate insulator for organic thin-film transistor applications as a result of its features of rapid heating (5 min) and low-power microwave-irradiation (50 W). PMID:28773101

Investigation of Rapid Low-Power Microwave-Induction Heating Scheme on the Cross-Linking Process of the Poly(4-vinylphenol for the Gate Insulator of Pentacene-Based Thin-Film Transistors

Directory of Open Access Journals (Sweden)

Ching-Lin Fan

2017-07-01

Full Text Available In this study, a proposed Microwave-Induction Heating (MIH scheme has been systematically studied to acquire suitable MIH parameters including chamber pressure, microwave power and heating time. The proposed MIH means that the thin indium tin oxide (ITO metal below the Poly(4-vinylphenol (PVP film is heated rapidly by microwave irradiation and the heated ITO metal gate can heat the PVP gate insulator, resulting in PVP cross-linking. It is found that the attenuation of the microwave energy decreases with the decreasing chamber pressure. The optimal conditions are a power of 50 W, a heating time of 5 min, and a chamber pressure of 20 mTorr. When suitable MIH parameters were used, the effect of PVP cross-linking and the device performance were similar to those obtained using traditional oven heating, even though the cross-linking time was significantly decreased from 1 h to 5 min. Besides the gate leakage current, the interface trap state density (Nit was also calculated to describe the interface status between the gate insulator and the active layer. The lowest interface trap state density can be found in the device with the PVP gate insulator cross-linked by using the optimal MIH condition. Therefore, it is believed that the MIH scheme is a good candidate to cross-link the PVP gate insulator for organic thin-film transistor applications as a result of its features of rapid heating (5 min and low-power microwave-irradiation (50 W.

Hydrolysis of bis(dimethylamido)tin to tin (II) oxyhydroxide and its selective transformation into tin (II) or tin (IV) oxide

KAUST Repository

Khanderi, Jayaprakash; Shi, Lei; Rothenberger, Alexander

2015-01-01

Sn6O4(OH)4, a hydrolysis product of Sn(NMe2)2, is transformed to tin (II) or tin (IV) oxide by solid and solution phase processing. Tin (II) oxide is formed by heating Sn6O4(OH)4 at ≤200 °C in air or under inert atmosphere. Tin (IV) oxide

Hydrogen-terminated diamond vertical-type metal oxide semiconductor field-effect transistors with a trench gate

Energy Technology Data Exchange (ETDEWEB)

Inaba, Masafumi, E-mail: inaba-ma@ruri.waseda.jp; Muta, Tsubasa; Kobayashi, Mikinori; Saito, Toshiki; Shibata, Masanobu; Matsumura, Daisuke; Kudo, Takuya; Hiraiwa, Atsushi [Graduate School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kawarada, Hiroshi [Graduate School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan); Kagami Memorial Laboratory for Materials Science and Technology, Waseda University, 2-8-26 Nishiwaseda, Shinjuku, Tokyo 169-0051 (Japan)

2016-07-18

The hydrogen-terminated diamond surface (C-H diamond) has a two-dimensional hole gas (2DHG) layer independent of the crystal orientation. A 2DHG layer is ubiquitously formed on the C-H diamond surface covered by atomic-layer-deposited-Al{sub 2}O{sub 3}. Using Al{sub 2}O{sub 3} as a gate oxide, C-H diamond metal oxide semiconductor field-effect transistors (MOSFETs) operate in a trench gate structure where the diamond side-wall acts as a channel. MOSFETs with a side-wall channel exhibit equivalent performance to the lateral C-H diamond MOSFET without a side-wall channel. Here, a vertical-type MOSFET with a drain on the bottom is demonstrated in diamond with channel current modulation by the gate and pinch off.

Injection of holes at indium tin oxide/dendrimer interface: An explanation with new theory of thermionic emission at metal/organic interfaces

International Nuclear Information System (INIS)

Peng Yingquan; Lu Feiping

2006-01-01

The traditional theory of thermionic emission at metal/inorganic crystalline semiconductor interfaces is no longer applicable for the interface between a metal and an organic semiconductor. Under the assumption of thermalization of hot carriers in the organic semiconductor near the interface, a theory for thermionic emission of charge carriers at metal/organic semiconductor interfaces is developed. This theory is used to explain the experimental result from Samuel group [J.P.J. Markham, D.W. Samuel, S.-C. Lo, P.L. Burn, M. Weiter, H. Baessler, J. Appl. Phys. 95 (2004) 438] for the injection of holes from indium tin oxide into the dendrimer based on fac-tris(2-phenylpyridyl) iridium(III)

IMPEDANCE SPECTROSCOPY OF POLYCRYSTALLINE TIN DIOXIDE FILMS

Directory of Open Access Journals (Sweden)

D. V. Adamchuck

2016-01-01

Full Text Available The aim of this work is the analysis of the influence of annealing in an inert atmosphere on the electrical properties and structure of non-stoichiometric tin dioxide films by means of impedance spectroscopy method. Non-stoichiometric tin dioxide films were fabricated by two-step oxidation of metallic tin deposited on the polycrystalline Al2O3 substrates by DC magnetron sputtering. In order to modify the structure and stoichiometric composition, the films were subjected to the high temperature annealing in argon atmosphere in temperature range 300–800 °С. AC-conductivity measurements of the films in the frequency range 20 Hz – 2 MHz were carried out. Variation in the frequency dependencies of the real and imaginary parts of the impedance of tin dioxide films was found to occur as a result of high-temperature annealing. Equivalent circuits for describing the properties of films with various structure and stoichiometric composition were proposed. Possibility of conductivity variation of the polycrystalline tin dioxide films as a result of аnnealing in an inert atmosphere was demonstrated by utilizing impedance spectroscopy. Annealing induces the recrystallization of the films, changing in their stoichiometry as well as increase of the sizes of SnO2 crystallites. Variation of electrical conductivity and structure of tin dioxide films as a result of annealing in inert atmosphere was confirmed by X-ray diffraction analysis. Analysis of the impedance diagrams of tin dioxide films was found to be a powerful tool to study their electrical properties. 

Single attosecond pulse generation by using plasmon-driven double optical gating technology in crossed metal nanostructures

Science.gov (United States)

Feng, Liqiang; Liu, Katheryn

2018-05-01

An effective method to obtain the single attosecond pulses (SAPs) by using the multi-cycle plasmon-driven double optical gating (DOG) technology in the specifically designed metal nanostructures has been proposed and investigated. It is found that with the introduction of the crossed metal nanostructures along the driven and the gating polarization directions, not only the harmonic cutoff can be extended, but also the efficient high-order harmonic generation (HHG) at the very highest orders occurs only at one side of the region inside the nanostructure. As a result, a 93 eV supercontinuum with the near stable phase can be found. Further, by properly introducing an ultraviolet (UV) pulse into the driven laser polarization direction (which is defined as the DOG), the harmonic yield can be enhanced by two orders of magnitude in comparison with the singe polarization gating (PG) technology. However, as the polarized angle or the ellipticity of the UV pulse increase, the enhancement of the harmonic yield is slightly reduced. Finally, by superposing the selected harmonics from the DOG scheme, a 30 as SAP with intensity enhancement of two orders of magnitude can be obtained.

Interface engineering and reliability characteristics of hafnium dioxide with poly silicon gate and dual metal (ruthenium-tantalum alloy, ruthenium) gate electrode for beyond 65 nm technology

Science.gov (United States)

Kim, Young-Hee

Chip density and performance improvements have been driven by aggressive scaling of semiconductor devices. In both logic and memory applications, SiO 2 gate dielectrics has reached its physical limit, direct tunneling resulting from scaling down of dielectrics thickness. Therefore high-k dielectrics have attracted a great deal of attention from industries as the replacement of conventional SiO2 gate dielectrics. So far, lots of candidate materials have been evaluated and Hf-based high-k dielectrics were chosen to the promising materials for gate dielectrics. However, lots of issues were identified and more thorough researches were carried out on Hf-based high-k dielectrics. For instances, mobility degradation, charge trapping, crystallization, Fermi level pinning, interface engineering, and reliability studies. In this research, reliability study of HfO2 were explored with poly gate and dual metal (Ru-Ta alloy, Ru) gate electrode as well as interface engineering. Hard breakdown and soft breakdown were compared and Weibull slope of soft breakdown was smaller than that of hard breakdown, which led to a potential high-k scaling issue. Dynamic reliability has been studied and the combination of trapping and detrapping contributed the enhancement of lifetime projection. Polarity dependence was shown that substrate injection might reduce lifetime projection as well as it increased soft breakdown behavior. Interface tunneling mechanism was suggested with dual metal gate technology. Soft breakdown (l st breakdown) was mainly due to one layer breakdown of bi-layer structure. Low weibull slope was in part attributed to low barrier height of HfO 2 compared to interface layer. Interface layer engineering was thoroughly studied in terms of mobility, swing, and short channel effect using deep sub-micron MOSFET devices. In fact, Hf-based high-k dielectrics could be scaled down to below EOT of ˜10A and it successfully achieved the competitive performance goals. However, it is

All-metallic electrically gated 2H-TaSe{sub 2} thin-film switches and logic circuits

Energy Technology Data Exchange (ETDEWEB)

Renteria, J.; Jiang, C.; Yan, Z. [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Samnakay, R.; Goli, P. [Materials Science and Engineering Program, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Pope, T. R.; Salguero, T. T. [Department of Chemistry, University of Georgia, Athens, Georgia 30602 (United States); Wickramaratne, D.; Lake, R. K. [Laboratory for Terascale and Terahertz Electronics, Department of Electrical Engineering, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Khitun, A. G. [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Materials Science and Engineering Program, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Balandin, A. A., E-mail: balandin@ee.ucr.edu [Nano-Device Laboratory, Department of Electrical Engineering, Bourns College of Engineering, University of California–Riverside, Riverside, California 92521 (United States); Department of Chemistry, University of Georgia, Athens, Georgia 30602 (United States)

2014-01-21

We report the fabrication and performance of all-metallic three-terminal devices with tantalum diselenide thin-film conducting channels. For this proof-of-concept demonstration, the layers of 2H-TaSe{sub 2} were exfoliated mechanically from single crystals grown by the chemical vapor transport method. Devices with nanometer-scale thicknesses exhibit strongly non-linear current-voltage characteristics, unusual optical response, and electrical gating at room temperature. We have found that the drain-source current in thin-film 2H-TaSe{sub 2}–Ti/Au devices reproducibly shows an abrupt transition from a highly resistive to a conductive state, with the threshold tunable via the gate voltage. Such current-voltage characteristics can be used, in principle, for implementing radiation-hard all-metallic logic circuits. These results may open new application space for thin films of van der Waals materials.

Evaluation of potential dietary toxicity of heavy metals in some common Nigerian beverages: A look at antimony, tin and mercury

Directory of Open Access Journals (Sweden)

I.I. Roberts

2011-11-01

Full Text Available There is currently little information on the composition of heavy metals in beverages imported and locally produced in Nigeria. The study quantitatively determined the composition of antimony (Sb, tin (Sn and mercury (Hg in 50 different beverage samples and evaluated the extent of violation of guideline values. Analysis of the beverage samples for the presence of Sb, Sn, and Hg was carried out using an atomic absorption spectrophotometer (AAS 929. The mean values detected for mercury, tin and antimony (±SE in fruit juices and soft drinks were 2.39±0.25, 3.66±0.22 and 0.49±0.048 μg/l; 2.93±0.34, 3.60±0.46 and 0.49±0.10 μg/l in dairy drinks and 0.94±0.02, 4.34±0.48 and 0.48±0.05 μg/l in bottled water samples respectively. While antimony detected in all products was below guideline values, mercury and tin were above the acceptable levels established by the World Health Organization, United States Environmental Protection Agency and European Union in most samples tested.

Research into tin and arsenical copper artefacts using nuclear analytical techniques

International Nuclear Information System (INIS)

Grant, M.R.

1995-01-01

This study includes the chemical analysis, sourcing and historical metallurgy of tin and arsenical copper artefacts discovered at Rooiberg and elsewhere in the Northern Transvaal and at Great Zimbabwe. A complete chemical analysis method for tin and cassiterite is presented, based on INAA (instrumental neutron activation analysis) and supplemented by PIXE or AAS for elements such as lead, bismuth and niobium. This is apparently the first study in which tin artefacts were analysed by INAA without chemical processing of the samples. INAA and PIXE returned the same results when a homogenized tin alloy block was analysed, but the structure and distribution of hardhead phases appear to produce an iron quantification problem in ancient tin. Ores and slags were analysed for light matrix elements by XRF or PIXE and INAA for the heavy trace metals. 108 refs., 24 figs., 130 tabs

Recovery of Tin and Nitric Acid from Spent Solder Stripping Solutions

International Nuclear Information System (INIS)

Ahn, Jae-Woo; Ryu, Seong-Hyung; Kim, Tae-young

2015-01-01

Spent solder-stripping solutions containing tin, copper, iron, and lead in nitric acid solution, are by-products of the manufacture of printed-circuit boards. The recovery of these metals and the nitric acid, for re-use has economic and environmental benefits. In the spent solder-stripping solution, a systematic method to determine a suitable process for recovery of valuable metals and nitric acid was developed. Initially, more than 90% of the tin was successfully recovered as high-purity SnO 2 by thermal precipitation at 80 ℃ for 3 hours. About 94% of the nitric acid was regenerated effectively from the spent solutions by diffusion dialysis, after which there remained copper, iron, and lead in solution. Leakage of tin through the anion-exchange membrane was the lowest (0.026%), whereas Pb-leakage was highest (4.26%). The concentration of the regenerated nitric acid was about 5.1 N.

Trace hydrogen extraction from liquid lithium tin alloy

International Nuclear Information System (INIS)

Xie Bo; Hu Rui; Xie Shuxian; Weng Kuiping

2010-01-01

In order to finish the design of tritium extraction system (TES) of fusion fission hybrid reactor (FFHR) tritium blanket, involving the dynamic mathematical model of liquid metal in contact with a gaseous atmosphere, approximate mathematical equation of tritium in lithium tin alloy was deduced. Moreover, carrying process used for trace hydrogen extraction from liquid lithium tin alloy was investigated with hydrogen being used to simulate tritium in the study. The study results indicate that carrying process is effective way for hydrogen extraction from liquid lithium tin alloy, and the best flow velocity of carrier gas is about 4 L/min under 1 kg alloy temperatures and carrying numbers are the main influencing factors of hydrogen number. Hydrogen extraction efficiency can reach 85% while the alloy sample is treated 6 times at 823 K. (authors)

Junctionless Thin-Film Transistors Gated by an H₃PO₄-Incorporated Chitosan Proton Conductor.

Science.gov (United States)

Liu, Huixuan; Xun, Damao

2018-04-01

We fabricated an H3PO4-incorporated chitosan proton conductor film that exhibited the electric double layer effect and showed a high specific capacitance of 4.42 μF/cm2. Transparent indium tin oxide thin-film transistors gated by H3PO4-incorporated chitosan films were fabricated by sputtering through a shadow mask. The operating voltage was as low as 1.2 V because of the high specific capacitance of the H3PO4-incorporated chitosan dielectrics. The junctionless transparent indium tin oxide thin film transistors exhibited good performance, including an estimated current on/off ratio and field-effect mobility of 1.2 × 106 and 6.63 cm2V-1s-1, respectively. These low-voltage thin-film electric-double-layer transistors gated by H3PO4-incorporated chitosan are promising for next generation battery-powered "see-through" portable sensors.

Structure, electronic properties, and oxygen incorporation/diffusion characteristics of the Σ 5 TiN(310)[001] tilt grain boundary

Science.gov (United States)

McKenna, Keith P.

2018-02-01

First principles calculations are employed to investigate the structure, electronic properties, and oxygen incorporation/diffusion characteristics of the Σ 5 TiN(310) tilt grain boundary with relevance to applications of polycrystalline TiN in microelectronics and protective coatings. We show that the grain boundary does not significantly modify electronic states near the Fermi energy but does induce an upward shift of up to 0.6 eV in a number of deeper occupied bands. We also show that oxygen is preferentially incorporated into the TiN grain boundary (GB) but must overcome relatively high activation energies for further diffusion. These predictions are consistent with the "stuffed barrier model" proposed to explain the good barrier characteristics of TiN. We also show that while the oxidizing power of TiN GBs is not sufficient to reduce HfO2 (a prototypical gate dielectric material), they can act as a scavenger for interstitial oxygen. Altogether, these results provide the much needed atomistic insights into the properties of a model GB in TiN and suggest a number of directions for future investigation.

Pourbaix Diagrams at Elevated Temperatures A Study of Zinc and Tin

Science.gov (United States)

Palazhchenko, Olga

Metals in industrial settings such as power plants are often subjected to high temperature and pressure aqueous environments, where failure to control corrosion compromises worker and environment safety. For instance, zircaloy (1.2-1.7 wt.% Sn) fuel rods are exposed to aqueous 250-310 °C coolant in CANDU reactors. The Pourbaix (EH-pH) diagram is a plot of electrochemical potential versus pH, which shows the domains of various metal species and by inference, corrosion susceptibility. Elevated temperature data for tin +II and tin +IV species were obtained using solid-aqueous phase equilibria with the respective oxides, in a batch vessel with in-situ pH measurement. Solubilities, determined via spectroscopic techniques, were used to calculate equilibrium constants and the Gibbs energies of Sn complexes for E-pH diagram construction. The SnOH3+ and Sn(OH )-5 species were incorporated, for the first time, into the 298.15 K and 358.15 K diagrams, with novel Go values determined at 358.15 K. Key words: Pourbaix diagrams, EH-pH, elevated temperatures, solubility, equilibrium, metal oxides, hydrolysis, redox potential, pH, thermochemical data, tin, zinc, zircaloy, corrosion, passivity.

Electrical analysis of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors on flexible bulk mono-crystalline silicon

KAUST Repository

Ghoneim, Mohamed T.

2015-06-01

We report on the electrical study of high dielectric constant insulator and metal gate metal oxide semiconductor capacitors (MOSCAPs) on a flexible ultra-thin (25 μm) silicon fabric which is peeled off using a CMOS compatible process from a standard bulk mono-crystalline silicon substrate. A lifetime projection is extracted using statistical analysis of the ramping voltage (Vramp) breakdown and time dependent dielectric breakdown data. The obtained flexible MOSCAPs operational voltages satisfying the 10 years lifetime benchmark are compared to those of the control MOSCAPs, which are not peeled off from the silicon wafer. © 2014 IEEE.

Peculiarities of the interaction of indium-tin and indium-bismuth alloys with ammonium halides

International Nuclear Information System (INIS)

Red'kin, A.N.; Smirnov, V.A.; Sokolova, E.A.; Makovej, Z.I.; Telegin, G.F.

1990-01-01

Peculiarities of fusible metal alloys interaction with ammonium halogenides in vertical reactor are considered using indium-tin and indium-bismuth binary alloys. It is shown that at the end of the process the composition of metal and salt phases is determined by the equilibrium type and constant characteristic of the given salt-metal system. As a result the interaction of indium-tin and indium-bismuth alloys with ammonium halogenides leads to preferential halogenation of indium-bismuth alloys with ammonium halogenides leads to preferential halogenation of indium which may be used in the processes of separation or purification. A model is suggested to calculate the final concentration of salt and metal phase components

High performance high-κ/metal gate complementary metal oxide semiconductor circuit element on flexible silicon

KAUST Repository

Sevilla, Galo T.

2016-02-29

Thinned silicon based complementary metal oxide semiconductor(CMOS)electronics can be physically flexible. To overcome challenges of limited thinning and damaging of devices originated from back grinding process, we show sequential reactive ion etching of silicon with the assistance from soft polymeric materials to efficiently achieve thinned (40 μm) and flexible (1.5 cm bending radius) silicon based functional CMOSinverters with high-κ/metal gate transistors. Notable advances through this study shows large area of silicon thinning with pre-fabricated high performance elements with ultra-large-scale-integration density (using 90 nm node technology) and then dicing of such large and thinned (seemingly fragile) pieces into smaller pieces using excimer laser. The impact of various mechanical bending and bending cycles show undeterred high performance of flexible siliconCMOSinverters. Future work will include transfer of diced silicon chips to destination site, interconnects, and packaging to obtain fully flexible electronic systems in CMOS compatible way.

Recovery Of Valuable Metals In Tin-Based Anodic Slimes By Carbothermic Reaction

Directory of Open Access Journals (Sweden)

Han Chulwoong

2015-06-01

Full Text Available This study investigated the recovery of anodic slimes by carbothermic reaction in the temperature range of 973~1,273K and amount of carbon as a function of time. Tin anodic slime samples were collected from the bottom of the electrolytic cells during the electro-refining of tin. The anodic slimes are consisted of high concentrated tin, silver, copper and lead oxides. The kinetics of reduction were determined by means of the weight-loss measurement technique. In order to understand in detail of carbothermic reaction, thermodynamic calculation was carried out and compared with experiments. From thermodynamic calculation and experiment, it was confirmed that Sn-based anodic slime could be reduced by controlling temperature and amount of carbon. However, any tendency between the reduction temperature and carbon content for the reduction reaction was not observed.

Study of the tunnelling initiated leakage current through the carbon nanotube embedded gate oxide in metal oxide semiconductor structures

International Nuclear Information System (INIS)

Chakraborty, Gargi; Sarkar, C K; Lu, X B; Dai, J Y

2008-01-01

The tunnelling currents through the gate dielectric partly embedded with semiconducting single-wall carbon nanotubes in a silicon metal-oxide-semiconductor (MOS) structure have been investigated. The application of the gate voltage to such an MOS device results in the band bending at the interface of the partly embedded oxide dielectric and the surface of the silicon, initiating tunnelling through the gate oxide responsible for the gate leakage current whenever the thickness of the oxide is scaled. A model for silicon MOS structures, where carbon nanotubes are confined in a narrow layer embedded in the gate dielectric, is proposed to investigate the direct and the Fowler-Nordheim (FN) tunnelling currents of such systems. The idea of embedding such elements in the gate oxide is to assess the possibility for charge storage for memory device applications. Comparing the FN tunnelling onset voltage between the pure gate oxide and the gate oxide embedded with carbon nanotubes, it is found that the onset voltage decreases with the introduction of the nanotubes. The direct tunnelling current has also been studied at very low gate bias, for the thin oxide MOS structure which plays an important role in scaling down the MOS transistors. The FN tunnelling current has also been studied with varying nanotube diameter

A high performance gate drive for large gate turn off thyristors

Energy Technology Data Exchange (ETDEWEB)

Szilagyi, C.P.

1993-01-01

Past approaches to gate turn-off (GTO) gating are application oriented, inefficient and dissipate power even when inactive. They allow the gate to avalanch, and do not reduce GTO turn-on and turn-off losses. A new approach is proposed which will allow modular construction and adaptability to large GTOs in the 50 amp to 2000 amp range. The proposed gate driver can be used in large voltage source and current source inverters and other power converters. The approach consists of a power metal-oxide-silicon field effect transistor (MOSFET) technology gating unit, with associated logic and supervisory circuits and an isolated flyback converter as the dc power source for the gating unit. The gate driver formed by the gating unit and the flyback converter is designed for 4000 V isolation. Control and supervisory signals are exchanged between the gate driver and the remote control system via fiber optics. The gating unit has programmable front-porch current amplitude and pulse-width, programmable closed-loop controlled back-porch current, and a turn-off switch capable of supplying negative gate current at demand as a function of peak controllable forward anode current. The GTO turn-on, turn-off and gate avalanch losses are reduced to a minimum. The gate driver itself has minimum operating losses. Analysis, design and practical realization are reported. 19 refs., 54 figs., 1 tab.

Metal-oxide assisted surface treatment of polyimide gate insulators for high-performance organic thin-film transistors.

Science.gov (United States)

Kim, Sohee; Ha, Taewook; Yoo, Sungmi; Ka, Jae-Won; Kim, Jinsoo; Won, Jong Chan; Choi, Dong Hoon; Jang, Kwang-Suk; Kim, Yun Ho

2017-06-14

We developed a facile method for treating polyimide-based organic gate insulator (OGI) surfaces with self-assembled monolayers (SAMs) by introducing metal-oxide interlayers, called the metal-oxide assisted SAM treatment (MAST). To create sites for surface modification with SAM materials on polyimide-based OGI (KPI) surfaces, the metal-oxide interlayer, here amorphous alumina (α-Al 2 O 3 ), was deposited on the KPI gate insulator using spin-coating via a rapid sol-gel reaction, providing an excellent template for the formation of a high-quality SAM with phosphonic acid anchor groups. The SAM of octadecylphosphonic acid (ODPA) was successfully treated by spin-coating onto the α-Al 2 O 3 -deposited KPI film. After the surface treatment by ODPA/α-Al 2 O 3 , the surface energy of the KPI thin film was remarkably decreased and the molecular compatibility of the film with an organic semiconductor (OSC), 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-C 10 ), was increased. Ph-BTBT-C 10 molecules were uniformly deposited on the treated gate insulator surface and grown with high crystallinity, as confirmed by atomic force microscopy (AFM) and X-ray diffraction (XRD) analysis. The mobility of Ph-BTBT-C 10 thin-film transistors (TFTs) was approximately doubled, from 0.56 ± 0.05 cm 2 V -1 s -1 to 1.26 ± 0.06 cm 2 V -1 s -1 , after the surface treatment. The surface treatment of α-Al 2 O 3 and ODPA significantly decreased the threshold voltage from -21.2 V to -8.3 V by reducing the trap sites in the OGI and improving the interfacial properties with the OSC. We suggest that the MAST method for OGIs can be applied to various OGI materials lacking reactive sites using SAMs. It may provide a new platform for the surface treatment of OGIs, similar to that of conventional SiO 2 gate insulators.

A Low Temperature Synthetic Route to Nanocrystalline TiN

African Journals Online (AJOL)

NICO

This method may be extended to the synthesis of other metal nitrides. ... direct current magnetron sputtering17, and mechanical mill- ... recent years, autoclaved synthesis of TiN nanomaterials from ... 3.2 XPS Characterization of the Samples.

A two dimensional analytical modeling of surface potential in triple metal gate (TMG) fully-depleted Recessed-Source/Drain (Re-S/D) SOI MOSFET

Science.gov (United States)

Priya, Anjali; Mishra, Ram Awadh

2016-04-01

In this paper, analytical modeling of surface potential is proposed for new Triple Metal Gate (TMG) fully depleted Recessed-Source/Dain Silicon On Insulator (SOI) Metal Oxide Semiconductor Field Effect Transistor (MOSFET). The metal with the highest work function is arranged near the source region and the lowest one near the drain. Since Recessed-Source/Drain SOI MOSFET has higher drain current as compared to conventional SOI MOSFET due to large source and drain region. The surface potential model developed by 2D Poisson's equation is verified by comparison to the simulation result of 2-dimensional ATLAS simulator. The model is compared with DMG and SMG devices and analysed for different device parameters. The ratio of metal gate length is varied to optimize the result.

Tailoring the structural and optical properties of TiN thin films by Ag ion implantation

Energy Technology Data Exchange (ETDEWEB)

Popović, M., E-mail: majap@vinca.rs; Novaković, M.; Rakočević, Z.; Bibić, N.

2016-12-15

Highlights: • Changes in structural and optical properties of TiN films induced by Ag ions. • The formation of Ag metallic clusters inside of TiN layers was observed. • The SPR of Ag particles was confirmed by a broad band in the spectra. • As the Ag ions fluence increases the n also increase and k values decrease. • With increasing ion fluence the TiN film becomes more metallic. - Abstract: Titanium nitride (TiN) thin films thickness of ∼260 nm prepared by dc reactive sputtering were irradiated with 200 keV silver (Ag) ions to the fluences ranging from 5 × 10{sup 15} ions/cm{sup 2} to 20 × 10{sup 15} ions/cm{sup 2}. After implantation TiN layers were annealed 2 h at 700 °C in a vacuum. Ion irradiation-induced microstructural changes were examined by using Rutherford backscattering spectrometry, X-ray diffraction and transmission electron microscopy, while the surface topography was observed using atomic force microscopy. Spectroscopic ellipsometry was employed to get insights on the optical and electronic properties of TiN films with respect to their microstructure. The results showed that the irradiations lead to deformation of the lattice, increasing disorder and formation of new Ag phase. The optical results demonstrate the contribution of surface plasmon resonace (SPR) of Ag particles. SPR position shifted in the range of 354.3–476.9 nm when Ag ion fluence varied from 5 × 10{sup 15} ions/cm{sup 2} to 20 × 10{sup 15} ions/cm{sup 2}. Shift in peak wavelength shows dependence on Ag particles concentration, suggesting that interaction between Ag particles dominate the surface plasmon resonance effect. Presence of Ag as second metal in the layer leads to overall decrease of optical resistivity of TiN.

Planar Indium Tin Oxide Heater for Improved Thermal Distribution for Metal Oxide Micromachined Gas Sensors

Directory of Open Access Journals (Sweden)

M. Cihan Çakır

2016-09-01

Full Text Available Metal oxide gas sensors with integrated micro-hotplate structures are widely used in the industry and they are still being investigated and developed. Metal oxide gas sensors have the advantage of being sensitive to a wide range of organic and inorganic volatile compounds, although they lack selectivity. To introduce selectivity, the operating temperature of a single sensor is swept, and the measurements are fed to a discriminating algorithm. The efficiency of those data processing methods strongly depends on temperature uniformity across the active area of the sensor. To achieve this, hot plate structures with complex resistor geometries have been designed and additional heat-spreading structures have been introduced. In this work we designed and fabricated a metal oxide gas sensor integrated with a simple square planar indium tin oxide (ITO heating element, by using conventional micromachining and thin-film deposition techniques. Power consumption–dependent surface temperature measurements were performed. A 420 °C working temperature was achieved at 120 mW power consumption. Temperature distribution uniformity was measured and a 17 °C difference between the hottest and the coldest points of the sensor at an operating temperature of 290 °C was achieved. Transient heat-up and cool-down cycle durations are measured as 40 ms and 20 ms, respectively.

Planar Indium Tin Oxide Heater for Improved Thermal Distribution for Metal Oxide Micromachined Gas Sensors.

Science.gov (United States)

Çakır, M Cihan; Çalışkan, Deniz; Bütün, Bayram; Özbay, Ekmel

2016-09-29

Metal oxide gas sensors with integrated micro-hotplate structures are widely used in the industry and they are still being investigated and developed. Metal oxide gas sensors have the advantage of being sensitive to a wide range of organic and inorganic volatile compounds, although they lack selectivity. To introduce selectivity, the operating temperature of a single sensor is swept, and the measurements are fed to a discriminating algorithm. The efficiency of those data processing methods strongly depends on temperature uniformity across the active area of the sensor. To achieve this, hot plate structures with complex resistor geometries have been designed and additional heat-spreading structures have been introduced. In this work we designed and fabricated a metal oxide gas sensor integrated with a simple square planar indium tin oxide (ITO) heating element, by using conventional micromachining and thin-film deposition techniques. Power consumption-dependent surface temperature measurements were performed. A 420 °C working temperature was achieved at 120 mW power consumption. Temperature distribution uniformity was measured and a 17 °C difference between the hottest and the coldest points of the sensor at an operating temperature of 290 °C was achieved. Transient heat-up and cool-down cycle durations are measured as 40 ms and 20 ms, respectively.

Chemical Speciation and Potential Mobility of Heavy Metals in the Soil of Former Tin Mining Catchment

Directory of Open Access Journals (Sweden)

M. A. Ashraf

2012-01-01

Full Text Available This study describes the chemical speciation of Pb, Zn, Cu, Cr, As, and Sn in soil of former tin mining catchment. Total five sites were selected for sampling and subsequent subsamples were collected from each site in order to create a composite sample for analysis. Samples were analysed by the sequential extraction procedure using optical emission spectrometry (ICP OES. Small amounts of Cu, Cr, and As retrieved from the exchangeable phase, the ready available for biogeochemical cycles in the ecosystem. Low quantities of Cu and As could be taken up by plants in these kind of acidic soils. Zn not detected in the bioavailable forms while Pb is only present in negligible amounts in very few samples. The absence of mobile forms of Pb eliminates the toxic risk both in the trophic chain and its migration downwards the soil profile. The results also indicate that most of the metals have high abundance in residual fraction indicating lithogenic origin and low bioavailability of the metals in the studied soil. The average potential mobility for the metals giving the following order: Sn > Cu > Zn > Pb > Cr > As.

Tin - an unlikely ally for silicon field effect transistors?

KAUST Repository

Hussain, Aftab M.; Fahad, Hossain M.; Singh, Nirpendra; Sevilla, Galo T.; Schwingenschlö gl, Udo; Hussain, Muhammad Mustafa

2014-01-01

We explore the effectiveness of tin (Sn), by alloying it with silicon, to use SiSn as a channel material to extend the performance of silicon based complementary metal oxide semiconductors. Our density functional theory based simulation shows

Gate-voltage control of equal-spin Andreev reflection in half-metal/semiconductor/superconductor junctions

Energy Technology Data Exchange (ETDEWEB)

Wu, Xiuqiang, E-mail: xianqiangzhe@126.com [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China); Meng, Hao, E-mail: menghao1982@shu.edu.cn [School of Physics and Telecommunication Engineering, Shanxi University of Technology, Hanzhong 723001 (China)

2016-04-22

With the Blonder–Tinkham–Klapwijk (BTK) approach, we investigate conductance spectrum in Ferromagnet/Semiconductor/Superconductor (FM/Sm/SC) double tunnel junctions where strong Rashba spin–orbit interaction (RSOI) is taken into account in semiconductors. For the half-metal limit, we find that the in-gap conductance becomes finite except at zero voltage when inserting a ferromagnetic insulator (FI) at the Sm/SC interface, which means that the appearance of a long-range triplet states in the half-metal. This is because of the emergence of the unconventional equal-spin Andreev reflection (ESAR). When the FI locates at the FM/Sm interface, however, we find the vanishing in-gap conductance due to the absence of the ESAR. Moreover, the non-zero in-gap conductance shows a nonmonotonic dependence on RSOI which can be controlled by applying an external gate voltage. Our results can be used to generate and manipulate the long-range spin triplet correlation in the nascent field of superconducting spintronics. - Highlights: • We study the equal-spin Andreev reflection in half-metal/semiconductor/superconductor (HM/Sm/SC) junctions. • The equal-spin Andreev reflection appearance when inserting a ferromagnetic insulator at the Sm/SC interface. • The finite in-gap conductance is attributed to the emergence of the equal-spin Andreev reflection. • The finite in-gap conductance shows a nonmonotonic dependence on Rashba spin–orbit interaction. • The finite in-gap conductance can be controlled by applying an external gate voltage.

Photolithographically Patterned TiO2 Films for Electrolyte-Gated Transistors.

Science.gov (United States)

Valitova, Irina; Kumar, Prajwal; Meng, Xiang; Soavi, Francesca; Santato, Clara; Cicoira, Fabio

2016-06-15

Metal oxides constitute a class of materials whose properties cover the entire range from insulators to semiconductors to metals. Most metal oxides are abundant and accessible at moderate cost. Metal oxides are widely investigated as channel materials in transistors, including electrolyte-gated transistors, where the charge carrier density can be modulated by orders of magnitude upon application of relatively low electrical bias (2 V). Electrolyte gating offers the opportunity to envisage new applications in flexible and printed electronics as well as to improve our current understanding of fundamental processes in electronic materials, e.g. insulator/metal transitions. In this work, we employ photolithographically patterned TiO2 films as channels for electrolyte-gated transistors. TiO2 stands out for its biocompatibility and wide use in sensing, electrochromics, photovoltaics and photocatalysis. We fabricated TiO2 electrolyte-gated transistors using an original unconventional parylene-based patterning technique. By using a combination of electrochemical and charge carrier transport measurements we demonstrated that patterning improves the performance of electrolyte-gated TiO2 transistors with respect to their unpatterned counterparts. Patterned electrolyte-gated (EG) TiO2 transistors show threshold voltages of about 0.9 V, ON/OFF ratios as high as 1 × 10(5), and electron mobility above 1 cm(2)/(V s).

Influence of multi-deposition multi-annealing on time-dependent dielectric breakdown characteristics of PMOS with high-k/metal gate last process

International Nuclear Information System (INIS)

Wang Yan-Rong; Yang Hong; Xu Hao; Wang Xiao-Lei; Luo Wei-Chun; Qi Lu-Wei; Zhang Shu-Xiang; Wang Wen-Wu; Yan Jiang; Zhu Hui-Long; Zhao Chao; Chen Da-Peng; Ye Tian-Chun

2015-01-01

A multi-deposition multi-annealing technique (MDMA) is introduced into the process of high-k/metal gate MOSFET for the gate last process to effectively reduce the gate leakage and improve the device’s performance. In this paper, we systematically investigate the electrical parameters and the time-dependent dielectric breakdown (TDDB) characteristics of positive channel metal oxide semiconductor (PMOS) under different MDMA process conditions, including the deposition/annealing (D and A) cycles, the D and A time, and the total annealing time. The results show that the increases of the number of D and A cycles (from 1 to 2) and D and A time (from 15 s to 30 s) can contribute to the results that the gate leakage current decreases by about one order of magnitude and that the time to fail (TTF) at 63.2% increases by about several times. However, too many D and A cycles (such as 4 cycles) make the equivalent oxide thickness (EOT) increase by about 1 Å and the TTF of PMOS worsen. Moreover, different D and A times and numbers of D and A cycles induce different breakdown mechanisms. (paper)

Characterization of tin oxide nanoparticles synthesized via oxidation from metal; Caracterizacao de nanoparticulas de oxido de estanho sintetizado via oxidacao do metal

Energy Technology Data Exchange (ETDEWEB)

Abruzzi, R.C.; Dedavid, B.A.; Pires, M.J.R.; Streicher, M., E-mail: afael.abruzzi@acad.pucrs.br [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Pos-Graduacao em Engenharia e Tecnologia de Materiais

2014-07-01

The tin oxide (SnO{sub 2}) is a promising material with great potential for applications such as gas sensors and catalysts. This oxide nanostructures show higher activation efficiency due to its larger effective surface. This paper presents the synthesis and characterization of the tin oxide in different conditions, via oxidation of pure tin with nitric acid. Results obtained from the characterization of SnO{sub 2} powder by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX), Particle size by Dynamic Light Scattering (DLS) and Infrared Spectroscopy (FTIR) indicated that the conditions were suitable for the synthesis to obtain manometric tin oxide granules with crystalline structure of rutile. (author)

The recovery of tin, and the production of niobium pentoxide and potassium tantalum fluoride, from a tin slag

International Nuclear Information System (INIS)

Iorio, G.; Tyler, M.S.

1987-01-01

This report describes the results of testwork on the recovery of tin, niobium, and tantalum from a tin slag. The slag, which consisted mainly of amorphous silica, with varying amounts of calcuim, magnesium, manganese, iron, and aluminium, contained an average of 8,8 per cent niobium pentoxide and 6,2 per cent tantalum pentoxide. The metallic tin-ion phase was removed from the crushed slag by magnetic separation. The slag was then leached with hydrochloric acid to remove magnesium, calcium, aluminium, iron, manganese, and the remainder of the tin. Leaching with sodium hydroxide for the removal of silica and phosphorous was followed by a final leach with hydrochloric acid for the removal of sodium. The upgraded concentrate thus obtained was purified by leaching with hydrofluoric acid, solvent extraction of niobium and tantalum into tri-n-butyl phosphate and methyl isobutyl ketone, and selective stripping of niobium with sulphuric acid and tantalum with ammonium floride. Niobium pentoxide and potassium tantalum fluoride were then precipitated by the addition of ammonium hydroxide and potassium fluoride to the respective strip liquors. The overall recoveries in the upgraded concentrate were 98 per cent for tantalum and 92 per cent for niobium. Dissolutions and recoveries of over 99 per cent were obtained for both tantalum and niobium in the purification steps. The niobium pentoxide and potassium tantalum fluoride precipitates obtained were of high purity

Large-Grain Tin-Rich Perovskite Films for Efficient Solar Cells via Metal Alloying Technique.

Science.gov (United States)

Tavakoli, Mohammad Mahdi; Zakeeruddin, Shaik Mohammed; Grätzel, Michael; Fan, Zhiyong

2018-03-01

Fast research progress on lead halide perovskite solar cells has been achieved in the past a few years. However, the presence of lead (Pb) in perovskite composition as a toxic element still remains a major issue for large-scale deployment. In this work, a novel and facile technique is presented to fabricate tin (Sn)-rich perovskite film using metal precursors and an alloying technique. Herein, the perovskite films are formed as a result of the reaction between Sn/Pb binary alloy metal precursors and methylammonium iodide (MAI) vapor in a chemical vapor deposition process carried out at 185 °C. It is found that in this approach the Pb/Sn precursors are first converted to (Pb/Sn)I 2 and further reaction with MAI vapor leads to the formation of perovskite films. By using Pb-Sn eutectic alloy, perovskite films with large grain sizes up to 5 µm can be grown directly from liquid phase metal. Consequently, using an alloying technique and this unique growth mechanism, a less-toxic and efficient perovskite solar cell with a power conversion efficiency (PCE) of 14.04% is demonstrated, while pure Sn and Pb perovskite solar cells prepared in this manner yield PCEs of 4.62% and 14.21%, respectively. It is found that this alloying technique can open up a new direction to further explore different alloy systems (binary or ternary alloys) with even lower melting point. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Heavy Metal Uptake by Nepenthes sp. in Ex-Iron and Tin Mine Soil, Pelepah Kanan, Kota Tinggi, Johor

International Nuclear Information System (INIS)

Sahibin Abd. Rahim; Tukimat Lihan; Zulfahmi Ali Rahman; Wan Mohd Razi Idris; Muhd Barzani Gasim; Azman Hashim; Sharilnizam Mohd. Yusof; Liow Hai Yin; Baba Musta; Adon Laming

2008-01-01

Heavy metals which are Pb, Co, Ni, Zn and Cd content in four Nephentes sp. plant component (roots, stem, leaf and pots) and in soil substrates from former iron and tin mining land at Pelepah Kanan, Kota Tinggi, Johor were determined. The composition of heavy metals in soil were extracted using a mixture of concentrated nitric acid and perchloric acid. Meanwhile, heavy metals in plants samples were extracted using wet digestion method. Heavy metals content in solution extract of soil and plant were determined by Flame Atomic Absorption Spectrophotometer (FAAS - model Perkin Elmer 3300). BAC (Biological Absorption Coefficient) which is a ratio of heavy metal content in plant to that of heavy metal in soil was obtained by calculation. The result of analyses showed that the former mining area has low organic matter contents and low values of soil electrical conductivity, whereas the soil pH showed an acidic value. Concentration of heavy metal in soil substrates in decreasing sequence start with Zn at 698.5 mg/ kg followed by Co (182.9 mg/ kg), Pb (58.2 mg/ kg), Ni (12.2 mg/ kg) and Cd (2.09 mg/ kg). Heavy metal concentration in plant in decreasing sequence was Ni>Co>Cd>Pb>Zn. Concentration in different part of the plant did not show any significant difference for all of the metals. Nepenthes sp. was found to accumulate high concentration of Ni as indicated by its high BAC value. This plant may be useful as bio-indicator for high concentration of Ni in soil. (author)

Health assessment for Tex Tin Corporation, National Priorities List Site, Texas City, Texas, Region 6. CERCLIS No. TXD062113329. Preliminary report

International Nuclear Information System (INIS)

1990-01-01

The Tex Tin Corporation facility, formerly Gulf Chemical and Metallurgical Corporation, is a proposed National Priorities List site located in Texas City, Galveston County, Texas. Tex Tin previously operated as a primary tin smelter, but currently operates as a copper smelter. Significant concentrations of metals (antimony, arsenic, barium, cadmium, chromium, copper, lead, manganese, mercury, nickel, silver, tin, and zinc) have been detected on-site in surface water, groundwater, and soil. Significant concentrations of metals (arsenic, cadmium, chromium, lead, nickel, and tin) have also been detected in ambient air samples collected off-site. Some remediation activities have occurred on-site including the closure of a 19-million-gallon ferric chloride pond and the removal of approximately 4,000 drums containing radioactive material. The Tex Tin site poses a potential public health concern for on-site workers, residents living in nearby neighborhoods, and possibly for a limited number of residents on private wells located within approximately one mile of the site

ABOUT THE WAYS OF THE SYSTEM ANALYSIS OF METAL MOVEMENT IN GATING SYSTEMS BASED ON THE NUMERICAL SOLUTIONS OF NAVIER-STOKES EQUATIONS

Directory of Open Access Journals (Sweden)

S. G. Lizouzov

2014-01-01

Full Text Available Numerical modeling of distribution of the fields of speeds projections on axes X, Y, Z in gating system with the casting “Case of conical pair” for various temporal values is carried out. Numerical criteria for assessment of metal movement through the feeders having various spatial location relative to the gating system are offered. Dynamics of change of the offered criteria on the basis of integral average value of the speed component on axes X, Y, Z in the gating systems at the outlet from feeder is calculated.

On the electrochemical migration mechanism of tin in electronics

DEFF Research Database (Denmark)

Minzari, Daniel; Jellesen, Morten Stendahl; Møller, Per

2011-01-01

Electrochemical migration (ECM) of tin can result in the growth of a metal deposit with a dendritic structure from cathode to anode. In electronics, such growth can lead to short circuit of biased electrodes, potentially leading to intermittent or complete failure of an electronic device...

Indoor guided evacuation: TIN for graph generation and crowd evacuation

Directory of Open Access Journals (Sweden)

Mengchao Xu

2016-05-01

Full Text Available This paper presents two complementary methods: an approach to compute a network data-set for indoor space of a building by using its two-dimensional (2D floor plans and limited semantic information, combined with an optimal crowd evacuation method. The approach includes three steps: (1 generate critical points in the space, (2 connect neighbour points to build up the network, and then (3 run the optimal algorithm for optimal crowd evacuation from a room to the exit gates of the building. Triangulated Irregular Network (TIN is used in the first two steps. The optimal evacuation crowd is not based on the nearest evacuation gate for a person but relies on optimal sorting of the waiting lists at each gate of the room to be evacuated. As an example case, a rectangular room with 52 persons with two gates is evacuated in 102 elementary interval times (one interval corresponds to the time for one step for normal velocity walking, whereas it would have been evacuated in not less than 167 elementary steps. The procedure for generating the customized network involves the use of 2D floor plans of a building and some common Geographic Information System (GIS functions. This method combined with the optimal sorting lists will be helpful for guiding crowd evacuation during any emergency.

Metal Whiskers: A Discussion of Risks and Mitigation

Science.gov (United States)

2010-11-30

efforts to investigate – Chromate conversion finishes DO NOT appear to stop whisker formation [4] S. Arnold, "Repressing the Growth of Tin Whiskers...November 30, 2010 Metal Whiskers 10 Examples of Metal Whiskers Zinc-Plated Steel Bus Rail with Yellow Chromate Conversion Finish Zinc whiskers grew...Metal Whiskers 11 Examples of Metal Whiskers Tin-Plated D-Sub Connector Shell Connector Advertised as “RoHS Compliant” November 30, 2010 Metal

Tinned fish with radioprotective ingredients

International Nuclear Information System (INIS)

Chaneva, M.; Minkova, M.; Zajko, G.

1992-01-01

A survey of food ingredients with pronounced radioprotective properties is made. The protective effect of fish proteins and some vegetable oils is mentioned. As suitable additives to tinned fish during the manufacturing process the β carotene, anthocyans and apple pectin are pointed out. β-carotene possesses the ability to absorb radiations. It can be added either as a pure crystalline substance or dissolved in the vegetable oil. Anthocyans have an antimutagen effect due to their ability to inhibit free radical reactions. Some vegetable polyphenols can be added with wine. The Bulgarian anthocyan concentrate Enobagrin (made by extraction of marc and wine) is also proposed. A combination of Enobagrin, β-tocopherol and pyracetam decreases the postradiation hypoplasia. Special attention is paid to the importance of the pectin in intoxication with heavy radioactive metals. It is thought that the pectin forms unsoluble complex compounds with Fe, Zn, Cd, Co, Pb, Hg, Mn, Cr. The binding energy depends on the available carboxylic groups. Some experiments showing the interaction of the pectin with 90 Sr are mentioned. In the tinned fish the pectin can be introduced with tomato paste. Vegetables rich in pectin and carotene - carrots and tomato concentrate - can be added as well. Proposed enriched tinned fish can be used as a preventive radioprotective food under conditions of increased radiation risk. 19 refs

Preparation and photovoltaic properties of CdS quantum dot-sensitized solar cell based on zinc tin mixed metal oxides.

Science.gov (United States)

Cao, Jiupeng; Zhao, Yifan; Zhu, Yatong; Yang, Xiaoyu; Shi, Peng; Xiao, Hongdi; Du, Na; Hou, Wanguo; Qi, Genggeng; Liu, Jianqiang

2017-07-15

The present study reports a new type of quantum dot sensitized solar cells (QDSSCs) using the zinc tin mixed metal oxides (MMO) as the anode materials, which were obtained from the layered double hydroxide (LDH) precursor. The successive ionic layer adsorption and reaction (SILAR) method is applied to deposit CdS quantum dots. The effects of sensitizing cycles on the performance of CdS QDSSC are studied. Scanning electron microscopy (SEM), Transmission electron microscope (TEM) and X-ray diffraction (XRD) are used to identify the surface profile and crystal structure of the mixed metal oxides anode. The photovoltaic performance of the QDSSC is studied by the electrochemical method. The new CdS QDSSC exhibits power conversion efficiency (PCE) up to 0.48% when the anode was sensitized for eight cycles. Copyright © 2017 Elsevier Inc. All rights reserved.

Electronegativity-dependent tin etching from thin films

Energy Technology Data Exchange (ETDEWEB)

Pachecka, M., E-mail: m.pachecka@utwente.nl; Sturm, J. M.; Kruijs, R. W. E. van de; Lee, C. J.; Bijkerk, F. [Industrial Focus Group XUV Optics, MESA+ Institute for Nanotechnology, University of Twente, Drienerlolaan 5, Enschede (Netherlands)

2016-07-15

The influence of a thin film substrate material on the etching of a thin layer of deposited tin (Sn) by hydrogen radicals was studied. The amount of remaining Sn was quantified for materials that cover a range of electronegativities. We show that, for metals, etching depends on the relative electronegativity of the surface material and Sn. Tin is chemically etched from surfaces with an electronegativity smaller than Sn, while incomplete Sn etching is observed for materials with an electronegativity larger than Sn. Furthermore, the amount of remaining Sn increases as the electronegativity of the surface material increases. We speculate, that, due to Fermi level differences in the material’s electronic structure, the energy of the two conduction bands shift such that the availability of electrons for binding with hydrogen is significantly reduced.

Electrical and materials properties of AlN/ HfO{sub 2} high-k stack with a metal gate

Energy Technology Data Exchange (ETDEWEB)

Reid, Kimberly G. [Tokyo Electron U.S., 14338 FM 1826, Austin, TX 78737 (United States)], E-mail: kim@ireid.com; Dip, Anthony [Tokyo Electron U.S., 2400 Grove Blvd., Austin, TX 78747 (United States)], E-mail: anthony.dip@us.tel.com; Sasaki, Sadao [Tokyo Electron U.S. (United States)], E-mail: Sadao.sasaki@us.tel.com; Triyoso, Dina [Freescale Semiconductor Inc., 3501 Ed Bluestein Blvd, Austin, TX 78721 (United States)], E-mail: Dina.Triyoso@freescale.com; Samavedam, Sri [Freescale Semiconductor Inc., 3501 Ed Bluestein Blvd, Austin, TX 78721 (United States)], E-mail: Sri.Samavedam@freescale.com; Gilmer, David [SEMATECH 2706 Montopolis Drive, Austin, TX 78741 (United States)], E-mail: David.Gilmer@sematech.org; Gondran, Carolyn F.H. [Process Characterization Laboratory, ATDF/SEMATECH, 2706 Montopolis Drive, Austin, Texas 78741 (United States)], E-mail: Carolyn.Gondran@atdf.com

2009-02-27

In this study, aluminum nitride (AlN) was grown by molecular layer deposition on HfO{sub 2} that had been deposited on 200 mm Si (100) substrates. The AlN was grown on HfO{sub 2} using sequential exposures of trimethyl-aluminum and ammonia (NH{sub 3}) in a batch vertical furnace. Excellent thickness uniformity on test wafers from the top of the furnace to the bottom of the furnace (across the furnace load) was obtained. The equivalent oxide thickness was 16.5-18.8 A for the AlN/HfO{sub 2} stack on patterned device wafers with a molybdenum oxynitride metal gate with leakage current densities from low 10{sup -5} to mid 10{sup -6} A/cm{sup 2} at threshold voltage minus one volt. There was no change in the work function with the AlN cap on HfO{sub 2} with the MoN metal gate, even with a 1000 deg. C anneal.

Vanadocene reactions with mixed acylates of silicon, germanium and tin

International Nuclear Information System (INIS)

Latyaeva, V.N.; Lineva, A.N.; Zimina, S.V.; Gordetsov, A.S.; Dergunov, Yu.I.

1981-01-01

Vanadocene interaction with di-and tri-alkyl (aryl)-derivatives of silicon, tin and germanium is studied. Dibutyltin dibenzoate under mild conditions (20 deg C, toluene) oxidates vanadocene to [CpV(OCOC 6 H 5 ) 2 ] 2 , at that, the splitting off of one Cp group in the form of cyclopentadiene and formation of the products of tin-organic fragment disproportionation (tributyltin benzoate, dibutyltin, metallic tin) take place. Tributyltin benzoate oxidates vanadocene at the mole ratio 2:1 and during prolong heating (120 deg C) in the absence of the solvent, [CpV(OCOC 6 H 5 ) 2 ] 2 and hexabutyldistannate are the products of the reaction. Acetates R 3 SnOCOCH 3 react in the similar way. The reactivity of mono- and diacylates of germanium and silicon decreases in the series of derivatives Sn>Ge>Si [ru

An analytical threshold voltage model for a short-channel dual-metal-gate (DMG) recessed-source/drain (Re-S/D) SOI MOSFET

Science.gov (United States)

Saramekala, G. K.; Santra, Abirmoya; Dubey, Sarvesh; Jit, Satyabrata; Tiwari, Pramod Kumar

2013-08-01

In this paper, an analytical short-channel threshold voltage model is presented for a dual-metal-gate (DMG) fully depleted recessed source/drain (Re-S/D) SOI MOSFET. For the first time, the advantages of recessed source/drain (Re-S/D) and of dual-metal-gate structure are incorporated simultaneously in a fully depleted SOI MOSFET. The analytical surface potential model at Si-channel/SiO2 interface and Si-channel/buried-oxide (BOX) interface have been developed by solving the 2-D Poisson’s equation in the channel region with appropriate boundary conditions assuming parabolic potential profile in the transverse direction of the channel. Thereupon, a threshold voltage model is derived from the minimum surface potential in the channel. The developed model is analyzed extensively for a variety of device parameters like the oxide and silicon channel thicknesses, thickness of source/drain extension in the BOX, control and screen gate length ratio. The validity of the present 2D analytical model is verified with ATLAS™, a 2D device simulator from SILVACO Inc.

Atomic-Layer-Deposited SnO2 as Gate Electrode for Indium-Free Transparent Electronics

KAUST Repository

Alshammari, Fwzah Hamud; Hota, Mrinal Kanti; Wang, Zhenwei; Aljawhari, Hala; Alshareef, Husam N.

2017-01-01

Atomic-layer-deposited SnO2 is used as a gate electrode to replace indium tin oxide (ITO) in thin-film transistors and circuits for the first time. The SnO2 films deposited at 200 °C show low electrical resistivity of ≈3.1 × 10−3 Ω cm with ≈93

Amphibolites in the Rare Metal- and Tin-bearing Bastar – Malkangiri ...

Indian Academy of Sciences (India)

33

21-10-284/1, Begumpet, Brahmanwadi Lane no. ... Odisha states of India, is well known for primary and secondary commercial deposits of tin .... carried out using the rapid wet chemical methods, essentially after Shapiro and Brannock. (1955).

Recovery and Purification of Tin from Tailings from the Penouta Sn–Ta–Nb Deposit

Directory of Open Access Journals (Sweden)

Félix Antonio López

2018-01-01

Full Text Available A concentrate obtained from mining tailings containing mainly cassiterite and columbotantalite was reduced for the production of tin metal. The compounds CaCO3, Na2CO3, K2CO3, and borax were used as fluxes in the pyrometallurgical reduction smelting process, and graphite was employed as the reducing agent. The greatest recovery of Sn (>95% was obtained when using CaCO3 as the flux; the purity of Sn was 96%. A slag equivalent to 25% of the mass of the initial concentrate was produced during the recovery of the Sn. This contained 45% Nb2O5 and Ta2O5, adding extra value to the mine tailings. The tin metal ingot was purified by electrorefining involving a tin and H2SO4 electrolyte solution and a 101.9 A/m2 current applied for 148 h. Under these conditions, 90 wt % of the Sn in the ingot was recovered at a purity of 99.97%.

Decomposition of SnH{sub 4} molecules on metal and metal–oxide surfaces

Energy Technology Data Exchange (ETDEWEB)

Ugur, D. [TNO, Stieltjesweg 1, 2628 CK Delft (Netherlands); Delft University of Technology, Department of Materials Science and Engineering, Mekelweg 2, 2628 CD Delft (Netherlands); Storm, A.J.; Verberk, R. [TNO, Stieltjesweg 1, 2628 CK Delft (Netherlands); Brouwer, J.C. [Delft University of Technology, Department of Materials Science and Engineering, Mekelweg 2, 2628 CD Delft (Netherlands); Sloof, W.G., E-mail: w.g.sloof@tudelft.nl [Delft University of Technology, Department of Materials Science and Engineering, Mekelweg 2, 2628 CD Delft (Netherlands)

2014-01-01

Atomic hydrogen cleaning is a promising method for EUV lithography systems, to recover from surface oxidation and to remove carbon and tin contaminants. Earlier studies showed, however, that tin may redeposit on nearby surfaces due to SnH{sub 4} decomposition. This phenomenon of SnH{sub 4} decomposition during tin cleaning has been quantified for various metallic and metal-oxide surfaces using X-ray photoelectron spectroscopy (XPS). It was observed that the metal oxide surfaces (TiO{sub 2} and ZrO{sub 2}) were significantly less contaminated than metallic surfaces. Tin contamination due to SnH{sub 4} decomposition can thus be reduced or even mitigated by application of a suitable metal-oxide coating.

TIN-X

DEFF Research Database (Denmark)

Cannon, Daniel C; Yang, Jeremy J; Mathias, Stephen L

2017-01-01

between proteins and diseases, based on text mining data processed from scientific literature. In the current implementation, TIN-X supports exploration of data for G-protein coupled receptors, kinases, ion channels, and nuclear receptors. TIN-X supports browsing and navigating across proteins......Motivation: The increasing amount of peer-reviewed manuscripts requires the development of specific mining tools to facilitate the visual exploration of evidence linking diseases and proteins. Results: We developed TIN-X, the Target Importance and Novelty eXplorer, to visualize the association...

Leakage current suppression with a combination of planarized gate and overlap/off-set structure in metal-induced laterally crystallized polycrystalline-silicon thin-film transistors

Science.gov (United States)

Chae, Hee Jae; Seok, Ki Hwan; Lee, Sol Kyu; Joo, Seung Ki

2018-04-01

A novel inverted staggered metal-induced laterally crystallized (MILC) polycrystalline-silicon (poly-Si) thin-film transistors (TFTs) with a combination of a planarized gate and an overlap/off-set at the source-gate/drain-gate structure were fabricated and characterized. While the MILC process is advantageous for fabricating inverted staggered poly-Si TFTs, MILC TFTs reveal higher leakage current than TFTs crystallized by other processes due to their high trap density of Ni contamination. Due to this drawback, the planarized gate and overlap/off-set structure were applied to inverted staggered MILC TFTs. The proposed device shows drastic suppression of leakage current and pinning phenomenon by reducing the lateral electric field and the space-charge limited current from the gate to the drain.

Characteristics of dual-gate thin-film transistors for applications in digital radiology

International Nuclear Information System (INIS)

Waechter, D.; Huang, Z.; Zhao, W.; Blevis, I.; Rowlands, J.A.

1996-01-01

A large-area flat-panel detector for digital radiology is being developed. The detector uses an array of dual-gate thin-film transistors (TFTs) to read out X-ray-generated charge produced in an amorphous selenium (a-Se) layer. The TFTs use CdSe as the semiconductor and use the bottom gate for row selection. The top gate can be divided into a 'deliberate' gate, covering most of the channel length, and small 'parasitic' gates that consist of: overlap of source or drain metal over the top-gate oxide; and gap regions in the metal that are covered only by the a-Se. In this paper we present the properties of dual-gate TFTs and examine the effect of both the deliberate and parasitic gates on the detector operation. Various options for controlling the top-gate potential are analyzed and discussed. (author)

Study of interfaces and band offsets in TiN/amorphous LaLuO3 gate stacks

KAUST Repository

Mitrovic, Ivona Z.

2011-07-01

TiN/LaLuO3 (LLO) gate stacks formed by molecular beam deposition have been investigated by X-ray photoelectron spectroscopy, medium energy ion scattering, spectroscopic ellipsometry, scanning transmission electron microscopy, electron energy loss spectroscopy and atomic force microscopy. The results indicate an amorphous structure for deposited LLO films. The band offset between the Fermi level of TiN and valence band of LLO is estimated to be 2.65 ± 0.05 eV. A weaker La-O-Lu bond and a prominent Ti2p sub-peak which relates to Ti bond to interstitial oxygen have been identified for an ultra-thin 1.7 nm TiN/3 nm LLO gate stack. The angle-dependent XPS analysis of Si2s spectra as well as shifts of La4d, La3d and Lu4d core levels suggests a silicate-type with Si-rich SiOx LLO/Si interface. Symmetrical valence and conduction band offsets for LLO to Si of 2.2 eV and the bandgap of 5.5 ± 0.1 eV have been derived from the measurements. The band alignment for ultra-thin TiN/LLO gate stack is affected by structural changes. Copyright © 2011 Published by Elsevier B.V. All rights reserved.

Structural and electrical characteristics of high-k/metal gate metal oxide semiconductor capacitors fabricated on flexible, semi-transparent silicon (100) fabric

KAUST Repository

Rojas, Jhonathan Prieto

2013-02-12

In pursuit of flexible computers with high performance devices, we demonstrate a generic process to fabricate 10 000 metal-oxide-semiconductor capacitors (MOSCAPs) with semiconductor industry\\'s most advanced high-k/metal gate stacks on widely used, inexpensive bulk silicon (100) wafers and then using a combination of iso-/anisotropic etching to release the top portion of the silicon with the already fabricated devices as a mechanically flexible (bending curvature of 133 m−1), optically semi-transparent silicon fabric (1.5 cm × 3 cm × 25 μm). The electrical characteristics show 3.7 nm effective oxide thickness, −0.2 V flat band voltage, and no hysteresis from the fabricated MOSCAPs.

Structural and electrical characteristics of high-k/metal gate metal oxide semiconductor capacitors fabricated on flexible, semi-transparent silicon (100) fabric

KAUST Repository

Rojas, Jhonathan Prieto; Hussain, Muhammad Mustafa; Sevilla, Galo T.

2013-01-01

In pursuit of flexible computers with high performance devices, we demonstrate a generic process to fabricate 10 000 metal-oxide-semiconductor capacitors (MOSCAPs) with semiconductor industry's most advanced high-k/metal gate stacks on widely used, inexpensive bulk silicon (100) wafers and then using a combination of iso-/anisotropic etching to release the top portion of the silicon with the already fabricated devices as a mechanically flexible (bending curvature of 133 m−1), optically semi-transparent silicon fabric (1.5 cm × 3 cm × 25 μm). The electrical characteristics show 3.7 nm effective oxide thickness, −0.2 V flat band voltage, and no hysteresis from the fabricated MOSCAPs.

On the electrochemistry of tin oxide coated tin electrodes in lithium-ion batteries

International Nuclear Information System (INIS)

Böhme, Solveig; Edström, Kristina; Nyholm, Leif

2015-01-01

As tin based electrodes are of significant interest in the development of improved lithium-ion batteries it is important to understand the associated electrochemical reactions. In this work it is shown that the electrochemical behavior of SnO_2 coated tin electrodes can be described based on the SnO_2 and SnO conversion reactions, the lithium tin alloy formation and the oxidation of tin generating SnF_2. The CV, XPS and SEM data, obtained for electrodeposited tin crystals on gold substrates, demonstrates that the capacity loss often observed for SnO_2 is caused by the reformed SnO_2 layer serving as a passivating layer protecting the remaining tin. Capacities corresponding up to about 80 % of the initial SnO_2 capacity could, however, be obtained by cycling to 3.5 V vs. Li"+/Li. It is also shown that the oxidation of the lithium tin alloy is hindered by the rate of the diffusion of lithium through a layer of tin with increasing thickness and that the irreversible oxidation of tin to SnF_2 at potentials larger than 2.8 V vs. Li"+/Li is due to the fact that SnF_2 is formed below the SnO_2 layer. This improved electrochemical understanding of the SnO_2/Sn system should be valuable in the development of tin based electrodes for lithium-ion batteries.

Indium tin oxide films prepared by atmospheric plasma annealing and their semiconductor-metal conductivity transition around room temperature

International Nuclear Information System (INIS)

Li Yali; Li Chunyang; He Deyan; Li Junshuai

2009-01-01

We report the synthesis of indium tin oxide (ITO) films using the atmospheric plasma annealing (APA) technique combined with the spin-coating method. The ITO film with a low resistivity of ∼4.6 x 10 -4 Ω cm and a high visible light transmittance, above 85%, was achieved. Hall measurement indicates that compared with the optimized ITO films deposited by magnetron sputtering, the above-mentioned ITO film has a higher carrier concentration of ∼1.21 x 10 21 cm -3 and a lower mobility of ∼11.4 cm 2 V -1 s -1 . More interestingly, these electrical characteristics result in the semiconductor-metal conductivity transition around room temperature for the ITO films prepared by APA.

Direct Structural Identification of Gas Induced Gate-Opening Coupled with Commensurate Adsorption in a Microporous Metal-Organic Framework.

Science.gov (United States)

Banerjee, Debasis; Wang, Hao; Plonka, Anna M; Emge, Thomas J; Parise, John B; Li, Jing

2016-08-08

Gate-opening is a unique and interesting phenomenon commonly observed in flexible porous frameworks, where the pore characteristics and/or crystal structures change in response to external stimuli such as adding or removing guest molecules. For gate-opening that is induced by gas adsorption, the pore-opening pressure often varies for different adsorbate molecules and, thus, can be applied to selectively separate a gas mixture. The detailed understanding of this phenomenon is of fundamental importance to the design of industrially applicable gas-selective sorbents, which remains under investigated due to the lack of direct structural evidence for such systems. We report a mechanistic study of gas-induced gate-opening process of a microporous metal-organic framework, [Mn(ina)2 ] (ina=isonicotinate) associated with commensurate adsorption, by a combination of several analytical techniques including single crystal X-ray diffraction, in situ powder X-ray diffraction coupled with differential scanning calorimetry (XRD-DSC), and gas adsorption-desorption methods. Our study reveals that the pronounced and reversible gate opening/closing phenomena observed in [Mn(ina)2 ] are coupled with a structural transition that involves rotation of the organic linker molecules as a result of interaction of the framework with adsorbed gas molecules including carbon dioxide and propane. The onset pressure to open the gate correlates with the extent of such interaction. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Formation of strain-induced quantum dots in gated semiconductor nanostructures

Directory of Open Access Journals (Sweden)

Ted Thorbeck

2015-08-01

Full Text Available A long-standing mystery in the field of semiconductor quantum dots (QDs is: Why are there so many unintentional dots (also known as disorder dots which are neither expected nor controllable. It is typically assumed that these unintentional dots are due to charged defects, however the frequency and predictability of the location of the unintentional QDs suggests there might be additional mechanisms causing the unintentional QDs besides charged defects. We show that the typical strains in a semiconductor nanostructure from metal gates are large enough to create strain-induced quantum dots. We simulate a commonly used QD device architecture, metal gates on bulk silicon, and show the formation of strain-induced QDs. The strain-induced QD can be eliminated by replacing the metal gates with poly-silicon gates. Thus strain can be as important as electrostatics to QD device operation operation.

Metal oxide nanorod arrays on monolithic substrates

Energy Technology Data Exchange (ETDEWEB)

Gao, Pu-Xian; Guo, Yanbing; Ren, Zheng

2018-01-02

A metal oxide nanorod array structure according to embodiments disclosed herein includes a monolithic substrate having a surface and multiple channels, an interface layer bonded to the surface of the substrate, and a metal oxide nanorod array coupled to the substrate surface via the interface layer. The metal oxide can include ceria, zinc oxide, tin oxide, alumina, zirconia, cobalt oxide, and gallium oxide. The substrate can include a glass substrate, a plastic substrate, a silicon substrate, a ceramic monolith, and a stainless steel monolith. The ceramic can include cordierite, alumina, tin oxide, and titania. The nanorod array structure can include a perovskite shell, such as a lanthanum-based transition metal oxide, or a metal oxide shell, such as ceria, zinc oxide, tin oxide, alumina, zirconia, cobalt oxide, and gallium oxide, or a coating of metal particles, such as platinum, gold, palladium, rhodium, and ruthenium, over each metal oxide nanorod. Structures can be bonded to the surface of a substrate and resist erosion if exposed to high velocity flow rates.

Effects of a metallic front gate on the temperature-dependent electronic property of pentacene films

Energy Technology Data Exchange (ETDEWEB)

Lin, Yow-Jon, E-mail: rzr2390@yahoo.com.tw [Institute of Photonics, National Changhua University of Education, Changhua 500, Taiwan (China); Tsao, Hou-Yen [Institute of Photonics, National Changhua University of Education, Changhua 500, Taiwan (China); Liu, Day-Shan [Graduate Institute of Electro-Optical and Materials Science, National Formosa University, Huwei 632, Taiwan (China)

2014-11-14

The effect of a metallic front gate on the temperature-dependent electronic property of pentacene films was investigated in this study. The carrier mobility exhibits strong temperature dependence, implying the dominance of tunneling (hopping) at low (high) temperatures. The room-temperature mobility was drastically increased by capping an In (Au) layer on the pentacene front surface. However, the carrier concentration is not affected. An increase in the phonon energy occurs for In-capped or Au-capped pentacene samples, which corresponds to the abrupt transition to the nonlocal electron–phonon coupling. The enhanced mobility by capping a metal layer is attributed to a change in the electron–phonon coupling. - Highlights: • For the metal-capped and uncapped pentacene films, the mobility was researched. • The mobility was dramatically increased by capping an In (Au) layer. • The induced strain by capping a metal layer is found. • The strain may lead to the electron–phonon coupling variation. • The enhanced mobility is attributed to the weakened electron–phonon coupling.

Physical Modeling of Gate-Controlled Schottky Barrier Lowering of Metal-Graphene Contacts in Top-Gated Graphene Field-Effect Transistors

Science.gov (United States)

Mao, Ling-Feng; Ning, Huansheng; Huo, Zong-Liang; Wang, Jin-Yan

2015-12-01

A new physical model of the gate controlled Schottky barrier height (SBH) lowering in top-gated graphene field-effect transistors (GFETs) under saturation bias condition is proposed based on the energy conservation equation with the balance assumption. The theoretical prediction of the SBH lowering agrees well with the experimental data reported in literatures. The reduction of the SBH increases with the increasing of gate voltage and relative dielectric constant of the gate oxide, while it decreases with the increasing of oxide thickness, channel length and acceptor density. The magnitude of the reduction is slightly enhanced under high drain voltage. Moreover, it is found that the gate oxide materials with large relative dielectric constant (>20) have a significant effect on the gate controlled SBH lowering, implying that the energy relaxation of channel electrons should be taken into account for modeling SBH in GFETs.

Physical Modeling of Gate-Controlled Schottky Barrier Lowering of Metal-Graphene Contacts in Top-Gated Graphene Field-Effect Transistors.

Science.gov (United States)

Mao, Ling-Feng; Ning, Huansheng; Huo, Zong-Liang; Wang, Jin-Yan

2015-12-17

A new physical model of the gate controlled Schottky barrier height (SBH) lowering in top-gated graphene field-effect transistors (GFETs) under saturation bias condition is proposed based on the energy conservation equation with the balance assumption. The theoretical prediction of the SBH lowering agrees well with the experimental data reported in literatures. The reduction of the SBH increases with the increasing of gate voltage and relative dielectric constant of the gate oxide, while it decreases with the increasing of oxide thickness, channel length and acceptor density. The magnitude of the reduction is slightly enhanced under high drain voltage. Moreover, it is found that the gate oxide materials with large relative dielectric constant (>20) have a significant effect on the gate controlled SBH lowering, implying that the energy relaxation of channel electrons should be taken into account for modeling SBH in GFETs.

LIQUID METAL COMPOSITIONS CONTAINING URANIUM

Science.gov (United States)

Teitel, R.J.

1959-04-21

Liquid metal compositions containing a solid uranium compound dispersed therein is described. Uranium combines with tin to form the intermetallic compound USn/sub 3/. It has been found that this compound may be incorporated into a liquid bath containing bismuth and lead-bismuth components, if a relatively small percentage of tin is also included in the bath. The composition has a low thermal neutron cross section which makes it suitable for use in a liquid metal fueled nuclear reactor.

Dual metal gate tunneling field effect transistors based on MOSFETs: A 2-D analytical approach

Science.gov (United States)

Ramezani, Zeinab; Orouji, Ali A.

2018-01-01

A novel 2-D analytical drain current model of novel Dual Metal Gate Tunnel Field Effect Transistors Based on MOSFETs (DMG-TFET) is presented in this paper. The proposed Tunneling FET is extracted from a MOSFET structure by employing an additional electrode in the source region with an appropriate work function to induce holes in the N+ source region and hence makes it as a P+ source region. The electric field is derived which is utilized to extract the expression of the drain current by analytically integrating the band to band tunneling generation rate in the tunneling region based on the potential profile by solving the Poisson's equation. Through this model, the effects of the thin film thickness and gate voltage on the potential, the electric field, and the effects of the thin film thickness on the tunneling current can be studied. To validate our present model we use SILVACO ATLAS device simulator and the analytical results have been compared with it and found a good agreement.

Epitaxial ZnO gate dielectrics deposited by RF sputter for AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors

Science.gov (United States)

Yoon, Seonno; Lee, Seungmin; Kim, Hyun-Seop; Cha, Ho-Young; Lee, Hi-Deok; Oh, Jungwoo

2018-01-01

Radio frequency (RF)-sputtered ZnO gate dielectrics for AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) were investigated with varying O2/Ar ratios. The ZnO deposited with a low oxygen content of 4.5% showed a high dielectric constant and low interface trap density due to the compensation of oxygen vacancies during the sputtering process. The good capacitance-voltage characteristics of ZnO-on-AlGaN/GaN capacitors resulted from the high crystallinity of oxide at the interface, as investigated by x-ray diffraction and high-resolution transmission electron microscopy. The MOS-HEMTs demonstrated comparable output electrical characteristics with conventional Ni/Au HEMTs but a lower gate leakage current. At a gate voltage of -20 V, the typical gate leakage current for a MOS-HEMT with a gate length of 6 μm and width of 100 μm was found to be as low as 8.2 × 10-7 mA mm-1, which was three orders lower than that of the Ni/Au Schottky gate HEMT. The reduction of the gate leakage current improved the on/off current ratio by three orders of magnitude. These results indicate that RF-sputtered ZnO with a low O2/Ar ratio is a good gate dielectric for high-performance AlGaN/GaN MOS-HEMTs.

Highly conducting and transparent sprayed indium tin oxide

Energy Technology Data Exchange (ETDEWEB)

Rami, M.; Benamar, E.; Messaoudi, C.; Sayah, D.; Ennaoui, A. (Faculte des Sciences, Rabat (Morocco). Lab. de Physique des Materiaux)

1998-03-01

Indium tin oxide (ITO) has a wide range of applications in solar cells (e.g. by controlling the resistivity, we can use low conductivity ITO as buffer layer and highly conducting ITO as front contact in thin films CuInS[sub 2] and CuInSe[sub 2] based solar cells) due to its wide band gap (sufficient to be transparent) in both visible and near infrared range, and high carrier concentrations with metallic conduction. A variety of deposition techniques such as reactive electron beam evaporation, DC magnetron sputtering, evaporation, reactive thermal deposition, and spray pyrolysis have been used for the preparation of undoped and tin doped indium oxide. This latter process which makes possible the preparation of large area coatings has attracted considerable attention due to its simplicity and large scale with low cost fabrication. It has been used here to deposit highly transparent and conducting films of tin doped indium oxide onto glass substrates. The electrical, optical and structural properties have been investigated as a function of various deposition parameters namely dopant concentrations, temperature and nature of substrates. X-ray diffraction patterns have shown that deposited films are polycrystalline without second phases and have preferred orientation [400]. INdium tin oxide layers with small resistivity value around 7.10[sup -5] [omega].cm and transmission coefficient in the visible and near IR range of about 85-90% have been easily obtained. (authors) 13 refs.

Comparative assessment of gastrointestinal irritant potency in man of tin(II) chloride and tin migrated from packaging.

Science.gov (United States)

Boogaard, Peter J; Boisset, Michel; Blunden, Steve; Davies, Scot; Ong, Teng Jin; Taverne, Jean-Pierre

2003-12-01

Tin is present in low concentrations in most canned foods and beverages, the highest levels being found in products packaged in unlacquered or partially lacquered tinplate cans. A limited number of case-reports of acute gastrointestinal disorders after consumption of food containing 100-500 mg/kg tin have been reported, but these reports suffer many insufficiencies. Controlled clinical studies on acute effects of tin migrated from packaging suggest a threshold concentration for adverse effects (AEs) of >730 mg/kg. Two separate randomised, single-centre, double-blind, crossover studies, enabling comparison of the tolerability of tin added as tin(II) chloride at concentrations of soup in 24 volunteers (Study 2) were carried out. Distribution studies were conducted to get insight in the acute AEs of low molecular weight (clear dose-response relationship was only observed when tin was added as tin(II) chloride in tomato juice. No clinically significant AEs were reported in Study 2 and comparison of the incidence of tin-related AEs showed no difference between the dose levels (including control). Tin species of low molecular weight in supernatant represented 31-32% of total tin in canned tomato soup versus 56-61% in juice freshly spiked with tin(II) chloride. Differences in the incidence of AEs following administration of tomato juice with 161 and 264 mg of tin per kg and tomato soup with 201 and 267 mg of tin per kg likely results from differences in the concentration of low molecular weight tin species and in the nature of tin complexes formed. The results of this work demonstrate that tin levels up to 267 mg/kg in canned food cause no AEs in healthy adults and support the currently proposed tin levels of 200 mg/kg and 250 mg/kg for canned beverages and canned foods, respectively, as safe levels for adults in the general population.

Gate-tunable gigantic lattice deformation in VO2

International Nuclear Information System (INIS)

Okuyama, D.; Hatano, T.; Nakano, M.; Takeshita, S.; Ohsumi, H.; Tardif, S.; Shibuya, K.; Yumoto, H.; Koyama, T.; Ohashi, H.; Takata, M.; Kawasaki, M.; Tokura, Y.; Iwasa, Y.; Arima, T.

2014-01-01

We examined the impact of electric field on crystal lattice of vanadium dioxide (VO 2 ) in a field-effect transistor geometry by in-situ synchrotron x-ray diffraction measurements. Whereas the c-axis lattice parameter of VO 2 decreases through the thermally induced insulator-to-metal phase transition, the gate-induced metallization was found to result in a significant increase of the c-axis length by almost 1% from that of the thermally stabilized insulating state. We also found that this gate-induced gigantic lattice deformation occurs even at the thermally stabilized metallic state, enabling dynamic control of c-axis lattice parameter by more than 1% at room temperature

Study of interfaces and band offsets in TiN/amorphous LaLuO3 gate stacks

KAUST Repository

Mitrovic, Ivona Z.; Simutis, G.; Davey, W. M.; Sedghi, Naser; Hall, Stephen D.; Dhanak, Vinod R.; Alexandrou, Ioannis; Wang, Qingxiao; Lopes, Joao Marcelo J.; Schubert, Jü rgen M.

2011-01-01

sub-peak which relates to Ti bond to interstitial oxygen have been identified for an ultra-thin 1.7 nm TiN/3 nm LLO gate stack. The angle-dependent XPS analysis of Si2s spectra as well as shifts of La4d, La3d and Lu4d core levels suggests a silicate-type

Hydrolysis of bis(dimethylamido)tin to tin (II) oxyhydroxide and its selective transformation into tin (II) or tin (IV) oxide

KAUST Repository

Khanderi, Jayaprakash

2015-03-01

Sn6O4(OH)4, a hydrolysis product of Sn(NMe2)2, is transformed to tin (II) or tin (IV) oxide by solid and solution phase processing. Tin (II) oxide is formed by heating Sn6O4(OH)4 at ≤200 °C in air or under inert atmosphere. Tin (IV) oxide nanoparticles are formed in the presence of a carboxylic acid and base in air at room temperature. IR spectroscopy, Raman spectroscopy, thermogravimetry (coupled with infrared spectroscopy), powder X-ray diffraction, high temperature X-ray diffraction, scanning electron and transmission electron microscopy are used for the characterization of Sn6O4(OH)4 and the investigation of its selective decomposition into SnO or SnO2. Spectroscopic and X-ray diffraction results indicate that SnO is formed by the removal of water from crystalline Sn6O4(OH)4. SEM shows octahedral morphology of the Sn6O4(OH)4, SnO and SnO2 with particle size from 400 nm-2 μm during solid state conversion. Solution phase transformation of Sn6O4(OH)4 to SnO2 occurs in the presence of potassium glutarate and oxygen. SnO2 particles are 15-20 nm in size.

Initial stages of indoor atmospheric corrosion of electronics contact metals in humid tropical climate: tin and nickel

Directory of Open Access Journals (Sweden)

Veleva, L.

2007-04-01

Full Text Available Samples of electrolytic tin and nickel have been exposed for 1 to 12 m in indoor environment, inside a box (rain sheltered cabinet, placed in tropical humid marine-urban climate, as a part of Gulf of Mexico. The corrosion aggressiveness of box has been classified as a very high corrosive, based on the monitored chlorides and SO₂ deposition rates, and the Temperature/Relative Humidity air daily complex. The annual mass increasing of nickel is approximately twice higher than its values of mass loss (C. The relation between nickel mass loss or increasing and time of wetness (t of metal surface is linear and does not obey the power equation C = A tⁿ, which has be found for tin. The SEM images reveal a localized corrosion on nickel and tin surfaces. XRD detects the formation of SnCl₂.H₂O as a corrosion product. Within the time on the tin surface appear black spots, considered as organic material.

Muestras de estaño y níquel electrolíticos han sido expuestas de 1 a 12 m en ambiente interno (indoor, en una caseta (gabinete protegido de lluvia, colocada en clima tropical húmedo marino-urbano del Golfo de México. La agresividad de la caseta ha sido clasificada como muy altamente corrosiva, basada al registro de la velocidad de deposición de cloruros y SO₂, y en el complejo diario de temperatura/humedad relativa del aire. El incremento de masa anual de níquel es, aproximadamente, dos veces mayor que del valor de su pérdida de masa (C. La relación entre la pérdida de masa de Ni o su incremento, y el tiempo de humectación (t de la superficie metálica y lineal y no obedece la ley de potencia C = A tⁿ , que ha sido encontrada para el estaño. Las imágenes del SEM revelan una corrosión localizada en las superficie de níquel y estaño. El análisis de rayos-X detecta la formación de SnCl₂.H₂O como producto de corrosión. Con el tiempo

Relative SHG measurements of metal thin films: Gold, silver, aluminum, cobalt, chromium, germanium, nickel, antimony, titanium, titanium nitride, tungsten, zinc, silicon and indium tin oxide

Directory of Open Access Journals (Sweden)

Franklin Che

Full Text Available We have experimentally measured the surface second-harmonic generation (SHG of sputtered gold, silver, aluminum, zinc, tungsten, copper, titanium, cobalt, nickel, chromium, germanium, antimony, titanium nitride, silicon and indium tin oxide thin films. The second-harmonic response was measured in reflection using a 150 fs p-polarized laser pulse at 1561 nm. We present a clear comparison of the SHG intensity of these films relative to each other. Our measured relative intensities compare favorably with the relative intensities of metals with published data. We also report for the first time to our knowledge the surface SHG intensity of tungsten and antimony relative to that of well known metallic thin films such as gold and silver. Keywords: Surface second-harmonic generation, Nonlinear optics, Metal thin films

Physical and Chemical Properties of TiOxNy Prepared by Low-Temperature Oxidation of Ultrathin Metal Nitride Directly Deposited on SiO2

Institute of Scientific and Technical Information of China (English)

HAN Yue-Ping; HAN Yan

2009-01-01

Physical and chemical properties of titanium oxynitride (TiOxNy) formed by low-temperature oxidation of titanium nitride (TIN) layer are investigated for advanced metal-oxide--semiconductor (MOS) gate dielectric application.TiOx Ny exhibits polycrystalline properties after the standard thermal process for MOS device fabrication,showing the preferred orientation at [200].Superior electrical properties of TiOxNy can be maintained before and after the annealing,probably due to the nitrogen incorporation in the oxide bulk and at the interface.Naturally formed transition layer between TiOxNy and SiO2 is also confirmed.

Sputtered tin oxide and titanium oxide thin films as alternative transparent conductive oxides

Energy Technology Data Exchange (ETDEWEB)

Boltz, Janika

2011-12-12

Alternative transparent conductive oxides to tin doped indium oxide have been investigated. In this work, antimony doped tin oxide and niobium doped titanium oxide have been studied with the aim to prepare transparent and conductive films. Antimony doped tin oxide and niobium doped titanium oxide belong to different groups of oxides; tin oxide is a soft oxide, while titanium oxide is a hard oxide. Both oxides are isolating materials, in case the stoichiometry is SnO{sub 2} and TiO{sub 2}. In order to achieve transparent and conductive films free carriers have to be generated by oxygen vacancies, by metal ions at interstitial positions in the crystal lattice or by cation doping with Sb or Nb, respectively. Antimony doped tin oxide and niobium doped titanium oxide films have been prepared by reactive direct current magnetron sputtering (dc MS) from metallic targets. The process parameters and the doping concentration in the films have been varied. The films have been electrically, optically and structurally analysed in order to analyse the influence of the process parameters and the doping concentration on the film properties. Post-deposition treatments of the films have been performed in order to improve the film properties. For the deposition of transparent and conductive tin oxide, the dominant parameter during the deposition is the oxygen content in the sputtering gas. The Sb incorporation as doping atoms has a minor influence on the electrical, optical and structural properties. Within a narrow oxygen content in the sputtering gas highly transparent and conductive tin oxide films have been prepared. In this study, the lowest resistivity in the as deposited state is 2.9 m{omega} cm for undoped tin oxide without any postdeposition treatment. The minimum resistivity is related to a transition to crystalline films with the stoichiometry of SnO{sub 2}. At higher oxygen content the films turn out to have a higher resistivity due to an oxygen excess. After post

Analyzing Single-Event Gate Ruptures In Power MOSFET's

Science.gov (United States)

Zoutendyk, John A.

1993-01-01

Susceptibilities of power metal-oxide/semiconductor field-effect transistors (MOSFET's) to single-event gate ruptures analyzed by exposing devices to beams of energetic bromine ions while applying appropriate bias voltages to source, gate, and drain terminals and measuring current flowing into or out of each terminal.

Fringing field effects in negative capacitance field-effect transistors with a ferroelectric gate insulator

Science.gov (United States)

Hattori, Junichi; Fukuda, Koichi; Ikegami, Tsutomu; Ota, Hiroyuki; Migita, Shinji; Asai, Hidehiro; Toriumi, Akira

2018-04-01

We study the effects of fringing electric fields on the behavior of negative-capacitance (NC) field-effect transistors (FETs) with a silicon-on-insulator body and a gate stack consisting of an oxide film, an internal metal film, a ferroelectric film, and a gate electrode using our own device simulator that can properly handle the complicated relationship between the polarization and the electric field in ferroelectric materials. The behaviors of such NC FETs and the corresponding metal-oxide-semiconductor (MOS) FETs are simulated and compared with each other to evaluate the effects of the NC of the ferroelectric film. Then, the fringing field effects are evaluated by comparing the NC effects in NC FETs with and without gate spacers. The fringing field between the gate stack, especially the internal metal film, and the source/drain region induces more charges at the interface of the film with the ferroelectric film. Accordingly, the function of the NC to modulate the gate voltage and the resulting function to improve the subthreshold swing are enhanced. We also investigate the relationships of these fringing field effects to the drain voltage and four design parameters of NC FETs, i.e., gate length, gate spacer permittivity, internal metal film thickness, and oxide film thickness.

Isotope Dilution - Thermal Ionisation Mass Spectrometric Analysis for Tin in a Fly Ash Material

International Nuclear Information System (INIS)

Hernandez, C.; Fernandez, M.; Quejido, A. L.

2006-01-01

Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solutions has been prepared from 112Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4,5 M HCI during 25 min ultrasound esposure time. Due to the complex matrix of this fly ash material, a two-steps purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10,10 + - 0,55 y 10,50 + - 0,64 imolg-1) are comprarable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference material certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of materials. (Author) 75 refs

Effects of Metallic Nanoparticles on Interfacial Intermetallic Compounds in Tin-Based Solders for Microelectronic Packaging

Science.gov (United States)

Haseeb, A. S. M. A.; Arafat, M. M.; Tay, S. L.; Leong, Y. M.

2017-10-01

Tin (Sn)-based solders have established themselves as the main alternative to the traditional lead (Pb)-based solders in many applications. However, the reliability of the Sn-based solders continues to be a concern. In order to make Sn-based solders microstructurally more stable and hence more reliable, researchers are showing great interest in investigating the effects of the incorporation of different nanoparticles into them. This paper gives an overview of the influence of metallic nanoparticles on the characteristics of interfacial intermetallic compounds (IMCs) in Sn-based solder joints on copper substrates during reflow and thermal aging. Nanocomposite solders were prepared by mechanically blending nanoparticles of nickel (Ni), cobalt (Co), zinc (Zn), molybdenum (Mo), manganese (Mn) and titanium (Ti) with Sn-3.8Ag-0.7Cu and Sn-3.5Ag solder pastes. The composite solders were then reflowed and their wetting characteristics and interfacial microstructural evolution were investigated. Through the paste mixing route, Ni, Co, Zn and Mo nanoparticles alter the morphology and thickness of the IMCs in beneficial ways for the performance of solder joints. The thickness of Cu3Sn IMC is decreased with the addition of Ni, Co and Zn nanoparticles. The thickness of total IMC layer is decreased with the addition of Zn and Mo nanoparticles in the solder. The metallic nanoparticles can be divided into two groups. Ni, Co, and Zn nanoparticles undergo reactive dissolution during solder reflow, causing in situ alloying and therefore offering an alternative route of alloy additions to solders. Mo nanoparticles remain intact during reflow and impart their influence as discrete particles. Mechanisms of interactions between different types of metallic nanoparticles and solder are discussed.

Hierarchical TiN nanoparticles-assembled nanopillars for flexible supercapacitors with high volumetric capacitance.

Science.gov (United States)

Qin, Ping; Li, Xingxing; Gao, Biao; Fu, Jijiang; Xia, Lu; Zhang, Xuming; Huo, Kaifu; Shen, Wenli; Chu, Paul K

2018-05-10

Titanium nitride (TiN) is an attractive electrode material in fast charging/discharging supercapacitors because of its excellent conductivity. However, the low capacitance and mechanical brittleness of TiN restricts its further application in flexible supercapacitors with high energy density. Thus, it is still a challenge to rationally design TiN electrodes with both high electrochemical and mechanical properties. Herein, the hierarchical TiN nanoparticles-assembled nanopillars (H-TiN NPs) array as binder free electrodes were obtained by nitriding of hierarchical titanium dioxide (TiO2) nanopillars, which was produced by a simple hydrothermal treatment of anodic TiO2 nanotubes (NTs) array in water. The porous TiN nanoparticles connected to each other to form ordered nanopillar arrays, effectively providing larger specific surface area and more active sites for charge storage. The H-TiN NPs delivered a high volumetric capacitance of 120 F cm-3 at 0.83 A cm-3, which is better than that of TiN NTs arrays (69 F cm-3 at 0.83 A cm-3). After assembling into all-solid-state devices, the H-TiN NPs based supercapacitors exhibited outstanding volumetric capacitance of 5.9 F cm-3 at 0.02 A cm-3 and a high energy density of 0.53 mW h cm-3. Our results reveal a new strategy to optimize the supercapacitive performance of metal nitrides.

Gate-controlled metal-insulator transition in the LaAlO{sub 3}/SrTiO{sub 3} system with sub-critical LaAlO{sub 3} thickness

Energy Technology Data Exchange (ETDEWEB)

Lee, Joon Sung; Lee, Seung Ran; Chang, Jung-Won; Noh, Hyunho; Baasandorj, Lkhagvasuren; Shim, Seung-Bo; Kim, Jinhee [Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of); Seung, Sang Keun; Shin, Hyun Sup; Song, Jonghyun [Department of Physics, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

2012-12-15

We studied the electrical conduction in the LaAlO{sub 3}/SrTiO{sub 3} (LAO/STO) interface electron system with a sub-critical LAO layer thickness of {proportional_to}3.5 unit cells (uc). It was found that the true dividing point between metallic and insulating behaviour without gating lies near the LAO thickness of 3.5 uc. Our marginally metallic 3.5 uc sample showed a sharp transition to insulating state at temperatures which strongly depended on the applied negative back-gate voltage. The superior gate-controllability of the sample was attributed to its sheet carrier density which was an order of magnitude lower than those of conducting LAO/STO samples with 4 uc or more of LAO layers. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Investigation of Tin and Molybdenum concentrations in the Soils in the southern part of the Silesian Upland

Directory of Open Access Journals (Sweden)

Bureć-Drewniak W.

2013-04-01

Full Text Available Majority of soils from the southern part of the Silesian Upland (Poland are highly degraded and contain elevated levels of heavy metals. Detailed studies, including dissemination, mobility and bioavailability have been conducted for most heavy metals, except tin and molybdenum. Therefore, the purpose of presented studies was evaluation of molybdenum and tin pollution and determination of their mobility and bioavailability in all soil types derived from the investigated area. A total of 9920 soil samples, including 5256 topsoil samples and 4664 subsoil samples were analyzed. Comparison of elements concentration between topsoil and subsoil allows identification of the source of pollution (natural or anthropogenic of tested elements.

Role of tin as a reducing agent in iron containing heat absorbing ...

Indian Academy of Sciences (India)

Unknown

infrared region and a narrow weak band for Fe3+ ion at its λmax at around 380 nm was observed in the silicate glass. ... Tin reducing agent; iron heat absorption; silicate glass. 1. ... ing point of aluminium metal is far below than the glass.

Scanning gate microscopy on graphene: charge inhomogeneity and extrinsic doping

International Nuclear Information System (INIS)

Jalilian, Romaneh; Tian Jifa; Chen, Yong P; Jauregui, Luis A; Lopez, Gabriel; Roecker, Caleb; Jovanovic, Igor; Yazdanpanah, Mehdi M; Cohn, Robert W

2011-01-01

We have performed scanning gate microscopy (SGM) on graphene field effect transistors (GFET) using a biased metallic nanowire coated with a dielectric layer as a contact mode tip and local top gate. Electrical transport through graphene at various back gate voltages is monitored as a function of tip voltage and tip position. Near the Dirac point, the response of graphene resistance to the tip voltage shows significant variation with tip position, and SGM imaging displays mesoscopic domains of electron-doped and hole-doped regions. Our measurements reveal substantial spatial fluctuation in the carrier density in graphene due to extrinsic local doping from sources such as metal contacts, graphene edges, structural defects and resist residues. Our scanning gate measurements also demonstrate graphene's excellent capability to sense the local electric field and charges.

Demonstration of AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors with silicon-oxy-nitride as the gate insulator

International Nuclear Information System (INIS)

Balachander, K.; Arulkumaran, S.; Egawa, T.; Sano, Y.; Baskar, K.

2005-01-01

AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOSHEMTs) were fabricated with plasma enhanced chemical vapor deposited silicon oxy-nitride (SiON) as an insulating layer. The compositions of SiON thin films were confirmed using X-ray photoelectron spectroscopy. The fabricated MOSHEMTs exhibited a very high saturation current density of 1.1 A/mm coupled with high positive operational gate voltage up to +7 V. The MOSHEMTs also exhibited four orders of low gate leakage current and high forward-on voltage when compared with the conventional HEMTs. The drain current collapse using gate pulse measurements showed only a negligible difference in the saturation current density revealing the drastic improvement in passivation of the surface states due to the high quality of dielectric thin films deposited. Thus, based on the improved direct-current operation, SiON can be considered to be a potential gate oxide comparable with other dielectric insulators

Plasma Deposited SiO2 for Planar Self-Aligned Gate Metal-Insulator-Semiconductor Field Effect Transistors on Semi-Insulating InP

Science.gov (United States)

Tabory, Charles N.; Young, Paul G.; Smith, Edwyn D.; Alterovitz, Samuel A.

1994-01-01

Metal-insulator-semiconductor (MIS) field effect transistors were fabricated on InP substrates using a planar self-aligned gate process. A 700-1000 A gate insulator of Si02 doped with phosphorus was deposited by a direct plasma enhanced chemical vapor deposition at 400 mTorr, 275 C, 5 W, and power density of 8.5 MW/sq cm. High frequency capacitance-voltage measurements were taken on MIS capacitors which have been subjected to a 700 C anneal and an interface state density of lxl0(exp 11)/eV/cq cm was found. Current-voltage measurements of the capacitors show a breakdown voltage of 107 V/cm and a insulator resistivity of 10(exp 14) omega cm. Transistors were fabricated on semi-insulating InP using a standard planar self-aligned gate process in which the gate insulator was subjected to an ion implantation activation anneal of 700 C. MIS field effect transistors gave a maximum extrinsic transconductance of 23 mS/mm for a gate length of 3 microns. The drain current drift saturated at 87.5% of the initial current, while reaching to within 1% of the saturated value after only 1x10(exp 3). This is the first reported viable planar InP self-aligned gate transistor process reported to date.

Effect of top gate potential on bias-stress for dual gate amorphous indium-gallium-zinc-oxide thin film transistor

Energy Technology Data Exchange (ETDEWEB)

Chun, Minkyu; Um, Jae Gwang; Park, Min Sang; Chowdhury, Md Delwar Hossain; Jang, Jin, E-mail: jjang@khu.ac.kr [Advanced Display Research Center and Department of Information Display, Kyung Hee University, Seoul 02447 (Korea, Republic of)

2016-07-15

We report the abnormal behavior of the threshold voltage (V{sub TH}) shift under positive bias Temperature stress (PBTS) and negative bias temperature stress (NBTS) at top/bottom gate in dual gate amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs). It is found that the PBTS at top gate shows negative transfer shift and NBTS shows positive transfer shift for both top and bottom gate sweep. The shift of bottom/top gate sweep is dominated by top gate bias (V{sub TG}), while bottom gate bias (V{sub BG}) is less effect than V{sub TG}. The X-ray photoelectron spectroscopy (XPS) depth profile provides the evidence of In metal diffusion to the top SiO{sub 2}/a-IGZO and also the existence of large amount of In{sup +} under positive top gate bias around top interfaces, thus negative transfer shift is observed. On the other hand, the formation of OH{sup −} at top interfaces under the stress of negative top gate bias shows negative transfer shift. The domination of V{sub TG} both on bottom/top gate sweep after PBTS/NBTS is obviously occurred due to thin active layer.

Analysis of gate underlap channel double gate MOS transistor for electrical detection of bio-molecules

Science.gov (United States)

Ajay; Narang, Rakhi; Saxena, Manoj; Gupta, Mridula

2015-12-01

In this paper, an analytical model for gate drain underlap channel Double-Gate Metal-Oxide-Semiconductor Field-Effect Transistor (DG-MOSFET) for label free electrical detection of biomolecules has been proposed. The conformal mapping technique has been used to derive the expressions for surface potential, lateral electric field, energy bands (i.e. conduction and valence band) and threshold voltage (Vth). Subsequently a full drain current model to analyze the sensitivity of the biosensor has been developed. The shift in the threshold voltage and drain current (after the biomolecules interaction with the gate underlap channel region of the MOS transistor) has been used as a sensing metric. All the characteristic trends have been verified through ATLAS (SILVACO) device simulation results.

Characterization of tin films synthesized from ethaline deep eutectic solvent

International Nuclear Information System (INIS)

Ghosh, Swatilekha; Roy, Sudipta

2014-01-01

Highlights: • Tin deposition was achieved by galvanostatic method on the basic substrates from ethaline deep eutectic solvent without use of any additives. • The current potential behaviour of tin system changes with increase in concentration of hydrated tin chloride in ethaline. • The deposition rate in ethaline display three times lower value compared to aqueous electrolytes. • Fine grained crystals of 62 ± 10 nm were obtained for tin deposits. • The deposition process is economical and can be adapted for industrial applications. - Abstract: Tin (Sn) films were electrodeposited by galvanostatic method from ethaline deep eutectic solvent (DES), without any additives. The effect of various deposition parameters on the microstructure was studied. With increase in metal salt concentration from 0.01 to 0.1 M, changes in current–potential behaviour were observed in the polarization scans. This might be due to the existence of [SnCl 3 ] − , [Sn 2 Cl 5 ] − complexes in ethaline DES. Smooth and homogeneous deposits were obtained on a steel substrate surface by applying current density of 1.57 × 10 −3 A/cm 2 at 25 °C. Under these conditions the deposition rate was found to be 0.1 ± 10% μm/min and current efficiency was obtained as 84 ± 3%. XRD analysis of the deposit confirmed the polycrystalline tetragonal structure with mostly (2 0 0) orientation having a crystallite size about 62 ± 16% nm along with an internal strain of 0.0031 ± 22%. The present deposition method is simple, economical and can be adapted for industrial applications

Heavy-ion-induced, gate-rupture in power MOSFETs

International Nuclear Information System (INIS)

Fischer, T.A.

1987-01-01

A new, heavy-ion-induced, burnout mechanism has been experimentally observed in power metal-oxide-semiconductor field-effect transistors (MOSFETs). This mechanism occurs when a heavy, charged particle passes through the gate oxide region of n- or p-channel devices having sufficient gate-to-source or gate-to-drain bias. The gate-rupture leads to significant permanent degradation of the device. A proposed failure mechanism is discussed and experimentally verified. In addition, the absolute immunity of p-channel devices to heavy-ion-induced, semiconductor burnout is demonstrated and discussed along with new, non-destructive, burnout testing methods

THE INFLUENCE OF NANOSECOND ELECTROMAGNETIC PULSES TO OBTAIN TIN AND THE PROPERTIES OF ITS ALLOYS

Directory of Open Access Journals (Sweden)

V. G. Komkov

2012-01-01

Full Text Available Experimentally found that the effect of nanosecond electromagnetic pulses to melt the charge, while the carbon thermal recovery of the tin ore, accelerates the formation of the metallic phase.

Electrical and optical properties of thin indium tin oxide films produced by pulsed laser ablation in oxygen or rare gas atmospheres

DEFF Research Database (Denmark)

Thestrup, B.; Schou, Jørgen; Nordskov, A.

1999-01-01

Films of indium tin oxide (ITO) have been produced in different background gases by pulsed laser deposition (PLD). The Films deposited in rare gas atmospheres on room temperature substrates were metallic, electrically conductive, but had poor transmission of visible light. For substrate temperatu......Films of indium tin oxide (ITO) have been produced in different background gases by pulsed laser deposition (PLD). The Films deposited in rare gas atmospheres on room temperature substrates were metallic, electrically conductive, but had poor transmission of visible light. For substrate...

Gate-tunable gigantic lattice deformation in VO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Okuyama, D., E-mail: okuyama@riken.jp, E-mail: nakano@imr.tohoku.ac.jp, E-mail: iwasa@ap.t.u-tokyo.ac.jp; Hatano, T. [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Nakano, M., E-mail: okuyama@riken.jp, E-mail: nakano@imr.tohoku.ac.jp, E-mail: iwasa@ap.t.u-tokyo.ac.jp [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Takeshita, S.; Ohsumi, H.; Tardif, S. [RIKEN SPring-8 Center, Hyogo 679-5148 (Japan); Shibuya, K. [National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8562 (Japan); Yumoto, H.; Koyama, T.; Ohashi, H. [Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198 (Japan); Takata, M. [RIKEN SPring-8 Center, Hyogo 679-5148 (Japan); Japan Synchrotron Radiation Research Institute, SPring-8, Hyogo 679-5198 (Japan); Kawasaki, M.; Tokura, Y.; Iwasa, Y., E-mail: okuyama@riken.jp, E-mail: nakano@imr.tohoku.ac.jp, E-mail: iwasa@ap.t.u-tokyo.ac.jp [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); Quantum-Phase Electronics Center and Department of Applied Physics, University of Tokyo, Tokyo 113-8656 (Japan); Arima, T. [RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198 (Japan); RIKEN SPring-8 Center, Hyogo 679-5148 (Japan); Department of Advanced Materials Science, University of Tokyo, Kashiwa 277-8561 (Japan)

2014-01-13

We examined the impact of electric field on crystal lattice of vanadium dioxide (VO{sub 2}) in a field-effect transistor geometry by in-situ synchrotron x-ray diffraction measurements. Whereas the c-axis lattice parameter of VO{sub 2} decreases through the thermally induced insulator-to-metal phase transition, the gate-induced metallization was found to result in a significant increase of the c-axis length by almost 1% from that of the thermally stabilized insulating state. We also found that this gate-induced gigantic lattice deformation occurs even at the thermally stabilized metallic state, enabling dynamic control of c-axis lattice parameter by more than 1% at room temperature.

High-performance a-IGZO thin-film transistor with conductive indium-tin-oxide buried layer

Science.gov (United States)

Ahn, Min-Ju; Cho, Won-Ju

2017-10-01

In this study, we fabricated top-contact top-gate (TCTG) structure of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) with a thin buried conductive indium-tin oxide (ITO) layer. The electrical performance of a-IGZO TFTs was improved by inserting an ITO buried layer under the IGZO channel. Also, the effect of the buried layer's length on the electrical characteristics of a-IGZO TFTs was investigated. The electrical performance of the transistors improved with increasing the buried layer's length: a large on/off current ratio of 1.1×107, a high field-effect mobility of 35.6 cm2/Vs, a small subthreshold slope of 116.1 mV/dec, and a low interface trap density of 4.2×1011 cm-2eV-1 were obtained. The buried layer a-IGZO TFTs exhibited enhanced transistor performance and excellent stability against the gate bias stress.

Selectivity of Catalytically Modified Tin Dioxide to CO and NH3 Gas Mixtures

Directory of Open Access Journals (Sweden)

Artem Marikutsa

2015-10-01

Full Text Available This paper is aimed at selectivity investigation of gas sensors, based on chemically modified nanocrystalline tin dioxide in the detection of CO and ammonia mixtures in air. Sol-gel prepared tin dioxide was modified by palladium and ruthenium oxides clusters via an impregnation technique. Sensing behavior to CO, NH3 and their mixtures in air was studied by in situ resistance measurements. Using the appropriate match of operating temperatures, it was shown that the reducing gases mixed in a ppm-level with air could be discriminated by the noble metal oxide-modified SnO2. Introducing palladium oxide provided high CO-sensitivity at 25–50 °C. Tin dioxide modified by ruthenium oxide demonstrated increased sensor signals to ammonia at 150–200 °C, and selectivity to NH3 in presence of higher CO concentrations.

Simultaneous determination of cadmium, iron and tin in canned foods using high-resolution continuum source graphite furnace atomic absorption spectrometry.

Science.gov (United States)

Leao, Danilo J; Junior, Mario M S; Brandao, Geovani C; Ferreira, Sergio L C

2016-06-01

A method was established to simultaneously determine cadmium, iron and tin in canned-food samples using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). The quantification step has been performed using the primary line (228.802nm) for cadmium and the adjacent secondary lines (228.725nm and 228.668nm) for iron and tin, respectively. The selected chemical modifier was an acid solution that contained a mixture of 0.1% (w/v) Pd and 0.05% (w/v) Mg. The absorbance signals were measured based on the peak area using 3 pixels for cadmium and 5 pixels for iron and tin. Under these conditions, cadmium, iron and tin have been determined in canned-food samples using the external calibration technique based on aqueous standards, where the limits of quantification were 2.10ngg(-1) for cadmium, 1.95mgkg(-1) for iron and 3.00mgkg(-1) for tin, and the characteristic masses were 1.0pg for cadmium, 0.9ng for iron and 1.1ng for tin. The precision was evaluated using two solutions of each metal ion, and the results, which were expressed as the relative standard deviation (RSD%), were 3.4-6.8%. The method accuracy for cadmium and iron was confirmed by analyzing a certified reference material of apple leaves (NIST 1515), which was supplied by NIST. However, for tin, the accuracy was confirmed by comparing the results of the proposed method and another analytical technique (inductively coupled plasma optical emission spectrometry). The proposed procedure was applied to determine cadmium, iron and tin in canned samples of peeled tomato and sardine. Eleven samples were analyzed, and the analyte concentrations were 3.57-62.9ngg(-1), 2.68-31.48mgkg(-1) and 4.06-122.0mgkg(-1) for cadmium, iron and tin, respectively. In all analyzed samples, the cadmium and tin contents were lower than the permissible maximum levels for these metals in canned foods in the Brazilian legislation. Copyright © 2016. Published by Elsevier B.V.

Gated field-emitter cathodes for high-power microwave applications

International Nuclear Information System (INIS)

Barasch, E.F.; Demroff, H.P.; Elliott, T.S.; Kasprowicz, T.B.; Lee, B.; Mazumdar, T.; McIntyre, P.M.; Pang, Y.; Smith, D.D.; Trost, H.J.

1992-01-01

Gated field-emitter cathodes have been fabricated on silicon wafers. Two fabrication approaches have been employed: a knife-edge array and a porous silicon structure. The knife-edge array consists of a pattern of knife-edges, sharpened to ∼200 A radius, configured with an insulated metal gate structure at a gap of ∼500 A. The porous silicon cathode consists of an insulating porous layer, containing pores of ∼50 A diameter, densely spaced in the native silicon, biased for field emission by a thin gate metallization on the surface. Emission current density of 20 A/cm 2 has been obtained with only 10 V bias. Fabrication processes and test results are presented. (Author) 4 figs., tab., 12 refs

In-Situ Growth and Characterization of Indium Tin Oxide Nanocrystal Rods

Directory of Open Access Journals (Sweden)

Yan Shen

2017-11-01

Full Text Available Indium tin oxide (ITO nanocrystal rods were synthesized in-situ by a vapor-liquid-solid (VLS method and electron beam evaporation technique. When the electron-beam gun bombarded indium oxide (In2O3 and tin oxide (SnO2 mixed sources, indium and tin droplets appeared and acted as catalysts. The nanocrystal rods were in-situ grown on the basis of the metal catalyst point. The nanorods have a single crystal structure. Its structure was confirmed by X-ray diffraction (XRD and transmission electron microscopy (TEM. The surface morphology was analyzed by scanning electron microscopy (SEM. During the evaporation, a chemical process was happened and an In2O3 and SnO2 solid solution was formed. The percentage of doped tin oxide was calculated by Vegard’s law to be 3.18%, which was in agreement with the mixture ratio of the experimental data. The single crystal rod had good semiconductor switch property and its threshold voltage of single rod was approximately 2.5 V which can be used as a micro switch device. The transmission rate of crystalline nanorods ITO film was over 90% in visible band and it was up to 95% in the blue green band as a result of the oxygen vacancy recombination luminescence.

Enhancement mode GaN-based multiple-submicron channel array gate-recessed fin metal-oxide-semiconductor high-electron mobility transistors

Science.gov (United States)

Lee, Ching-Ting; Wang, Chun-Chi

2018-04-01

To study the function of channel width in multiple-submicron channel array, we fabricated the enhancement mode GaN-based gate-recessed fin metal-oxide-semiconductor high-electron mobility transistors (MOS-HEMTs) with a channel width of 450 nm and 195 nm, respectively. In view of the enhanced gate controllability in a narrower fin-channel structure, the transconductance was improved from 115 mS/mm to 151 mS/mm, the unit gain cutoff frequency was improved from 6.2 GHz to 6.8 GHz, and the maximum oscillation frequency was improved from 12.1 GHz to 13.1 GHz of the devices with a channel width of 195 nm, compared with the devices with a channel width of 450 nm.

Ion transport by gating voltage to nanopores produced via metal-assisted chemical etching method

Science.gov (United States)

Van Toan, Nguyen; Inomata, Naoki; Toda, Masaya; Ono, Takahito

2018-05-01

In this work, we report a simple and low-cost way to create nanopores that can be employed for various applications in nanofluidics. Nano sized Ag particles in the range from 1 to 20 nm are formed on a silicon substrate with a de-wetting method. Then the silicon nanopores with an approximate 15 nm average diameter and 200 μm height are successfully produced by the metal-assisted chemical etching method. In addition, electrically driven ion transport in the nanopores is demonstrated for nanofluidic applications. Ion transport through the nanopores is observed and could be controlled by an application of a gating voltage to the nanopores.

Study of strength of Dsub(y)150 gate valve case, manufactured by centrifugal casting

International Nuclear Information System (INIS)

Umanskaya, L.G.; Semenov, P.V.; Tinyakov, V.G.; Babkina, R.I.; Khatuntsev, Eh.V.

1982-01-01

A process for manufacturing centrifugal-cast gate valve body is developed. Structural strength of such items, homogeneity, ductile and strength properties over the cross section as well as the metal susceptibility to embrittlement have been investigated. Three cast gate valve bodies have been taken: one - of 20GSL steel - for hydraulic testing, and two - of 15Kh1MFL steel - for investigation into the metal properties across the valve thickness. The strength properties of the centrifugal-cast gate valve body of 15Kh1M1FL steel are stated to meet the specifications. The gate valve metal ductility (delta and PSI) is twice as high as that of a sand-cast valve. The microstructure, strength and ductility are uniform both over wall thickness and over different body cross sections

Quantum design rules for single molecule logic gates.

Science.gov (United States)

Renaud, N; Hliwa, M; Joachim, C

2011-08-28

Recent publications have demonstrated how to implement a NOR logic gate with a single molecule using its interaction with two surface atoms as logical inputs [W. Soe et al., ACS Nano, 2011, 5, 1436]. We demonstrate here how this NOR logic gate belongs to the general family of quantum logic gates where the Boolean truth table results from a full control of the quantum trajectory of the electron transfer process through the molecule by very local and classical inputs practiced on the molecule. A new molecule OR gate is proposed for the logical inputs to be also single metal atoms, one per logical input.

Improved Long-Term Stability of Transparent Conducting Electrodes Based on Double-Laminated Electrosprayed Antimony Tin Oxides and Ag Nanowires

Directory of Open Access Journals (Sweden)

Koo B.-R.

2017-06-01

Full Text Available We fabricated double-laminated antimony tin oxide/Ag nanowire electrodes by spin-coating and electrospraying. Compared to pure Ag nanowire electrodes and single-laminated antimony tin oxide/Ag nanowire electrodes, the double-laminated antimony tin oxide/Ag nanowire electrodes had superior transparent conducting electrode performances with sheet resistance ~19.8 Ω/□ and optical transmittance ~81.9%; this was due to uniform distribution of the connected Ag nanowires because of double lamination of the metallic Ag nanowires without Ag aggregation despite subsequent microwave heating at 250°C. They also exhibited excellent and superior long-term chemical and thermal stabilities and adhesion to substrate because double-laminated antimony tin oxide thin films act as the protective layers between Ag nanowires, blocking Ag atoms penetration.

Novel WSi/Au T-shaped gate GaAs metal-semiconductor field-effect-transistor fabrication process for super low-noise microwave monolithic integrated circuit amplifiers

International Nuclear Information System (INIS)

Takano, H.; Hosogi, K.; Kato, T.

1995-01-01

A fully ion-implanted self-aligned T-shaped gate Ga As metal-semiconductor field-effect transistor (MESFET) with high frequency and extremely low-noise performance has been successfully fabricated for super low-noise microwave monolithic integrated circuit (MMIC) amplifiers. A subhalf-micrometer gate structure composed of WSi/Ti/Mo/Au is employed to reduce gate resistance effectively. This multilayer gate structure is formed by newly developed dummy SiON self-alignment technology and a photoresist planarization process. At an operating frequency of 12 GHz, a minimum noise figure of 0.87 dB with an associated gain of 10.62 dB has been obtained. Based on the novel FET process, a low-noise single-stage MMIC amplifier with an excellent low-noise figure of 1.2 dB with an associated gain of 8 dB in the 14 GHz band has been realized. This is the lowest noise figure ever reported at this frequency for low-noise MMICs based on ion-implanted self-aligned gate MESFET technology. 14 refs., 9 figs

Synthesising highly reactive tin oxide using Tin(II2- ethylhexanoate polynucleation as precursor

Directory of Open Access Journals (Sweden)

Alejandra Montenegro Hernández

2009-01-01

Full Text Available Tin oxide is a widely used compound in technological applications, particularity as a catalyst, gas sensor and in making varistors, transparent conductors, electrocatalytic electrodes and photovoltaic cells. An ethylhexanoate tin salt, a carboxylic acid and poly-esterification were used for synthesising highly reactive tin oxide in the present study. Synthesis was controlled by Fourier transform infrared (FTIR spectroscopy and recording changes in viscosity. The tin oxide characteristics so obtained were determined using FTIR spectroscopy, X-ray diffraction (XRD and scanning electron microscopy (SEM. The SnO2 dust synthesised and heat-treated at 550°C yielded high density aggregates, having greater than 50 μm particle size. This result demonstrates the high reactivity of the ceramic powders synthesised here.

Measuring the sustainability of tin in China.

Science.gov (United States)

Yang, Congren; Tan, Quanyin; Zeng, Xianlai; Zhang, Yuping; Wang, Zhishi; Li, Jinhui

2018-09-01

Tin is a component of many items used in daily activities, including solder in consumer electronics, tin can containing food and beverages, polyvinyl chloride stabilizers in construction products, catalysts in industrial processes, etc. China is the largest producer and consumer of refined tin, and more than 60% of this refined tin is applied in the electronics sector as solder. China is the leader in global economic growth; simultaneously, China is also a major producer and consumer of electrical and electronic equipment (EEE). Thus, future tin supply and demand in China are forecasted, based on the gross domestic product per capita and the average consumption of refined tin in past five years. Current tin reserves and identified resources in China can meet the future two decades of mine production, but import of tin will also be critical for China's future tin consumption. However, there will be a lot of uncertainty for import of tin from other countries. At the same time, virgin mining of geological ores is a process of high energy consumption and destruction of the natural environment. Hence recycling tin from Sn-bearing secondary resources like tailings and waste electrical and electronic equipment (WEEE) can not only address the shortage of tin mineral resources, but also save energy and protect the ecological environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Trap state passivation improved hot-carrier instability by zirconium-doping in hafnium oxide in a nanoscale n-metal-oxide semiconductor-field effect transistors with high-k/metal gate

International Nuclear Information System (INIS)

Liu, Hsi-Wen; Tsai, Jyun-Yu; Liu, Kuan-Ju; Lu, Ying-Hsin; Chang, Ting-Chang; Chen, Ching-En; Tseng, Tseung-Yuen; Lin, Chien-Yu; Cheng, Osbert; Huang, Cheng-Tung; Ye, Yi-Han

2016-01-01

This work investigates the effect on hot carrier degradation (HCD) of doping zirconium into the hafnium oxide high-k layer in the nanoscale high-k/metal gate n-channel metal-oxide-semiconductor field-effect-transistors. Previous n-metal-oxide semiconductor-field effect transistor studies demonstrated that zirconium-doped hafnium oxide reduces charge trapping and improves positive bias temperature instability. In this work, a clear reduction in HCD is observed with zirconium-doped hafnium oxide because channel hot electron (CHE) trapping in pre-existing high-k bulk defects is the main degradation mechanism. However, this reduced HCD became ineffective at ultra-low temperature, since CHE traps in the deeper bulk defects at ultra-low temperature, while zirconium-doping only passivates shallow bulk defects.

Synchrotron radiation x-ray photoelectron spectroscopy study on the interface chemistry of high-k PrxAl2-xO3 (x=0-2) dielectrics on TiN for dynamic random access memory applications

Science.gov (United States)

Schroeder, T.; Lupina, G.; Sohal, R.; Lippert, G.; Wenger, Ch.; Seifarth, O.; Tallarida, M.; Schmeisser, D.

2007-07-01

Engineered dielectrics combined with compatible metal electrodes are important materials science approaches to scale three-dimensional trench dynamic random access memory (DRAM) cells. Highly insulating dielectrics with high dielectric constants were engineered in this study on TiN metal electrodes by partly substituting Al in the wide band gap insulator Al2O3 by Pr cations. High quality PrAlO3 metal-insulator-metal capacitors were processed with a dielectric constant of 19, three times higher than in the case of Al2O3 reference cells. As a parasitic low dielectric constant interface layer between PrAlO3 and TiN limits the total performance gain, a systematic nondestructive synchrotron x-ray photoelectron spectroscopy study on the interface chemistry of PrxAl2-xO3 (x =0-2) dielectrics on TiN layers was applied to unveil its chemical origin. The interface layer results from the decreasing chemical reactivity of PrxAl2-xO3 dielectrics with increasing Pr content x to reduce native Ti oxide compounds present on unprotected TiN films. Accordingly, PrAlO3 based DRAM capacitors require strict control of the surface chemistry of the TiN electrode, a parameter furthermore of importance to engineer the band offsets of PrxAl2-xO3/TiN heterojunctions.

Synthesis and characterization of tin(IV) antimonate and study of its ion-exchange equilibria

International Nuclear Information System (INIS)

Burham, N.; Abdel-Halim, S.H.; El-Shahat, M.F.

1995-01-01

Tin(IV) antimonate with different Sb/Sn molar ratios has been prepared. The characterization of the product materials was carried out using X-ray diffraction pattern, thermal analysis and infrared spectra. The saturation capacities of sodium and cesium were found to increase with Sb/Sn molar ratios. The K d values on thermal treatment of tin(IV) antimonate, as a cation exchanger, have been measured for some heavy metal ions in the temperature range of 50-400 deg C. The maximum adsorption of 10 -4 M of the metal ions studied was obtained at 400 deg C. The selectivity sequence was Eu 3+ > Co 2+ > Sr 2+ > Cs + for the sample heated up to 400 deg C. No adsorption was observed on the sample heated at 700 deg C because of the formation of SnO 2 and Sb 6 O 13 . (author) 9 refs.; 7 figs.; 5 tabs

Low-temperature Synthesis of Tin(II) Oxide From Tin(II) ketoacidoximate Precursor

KAUST Repository

Alshankiti, Buthainah

2015-01-01

Sn (II) oxide finds numerous applications in different fields such as thin film transistors1, solar cells2 and sensors.3 In this study we present the fabrication of tin monoxide SnO by using Sn (II) ketoacid oximate complexes as precursors. Tin (II

GEMAS - Tin and Tungsten: possible sources of enriched concentrations in soils in European countries

Science.gov (United States)

João Batista, Maria; Filipe, Augusto; Reimann, Clemens

2014-05-01

southern soils and SiO2 is higher in loess sediments region, in the North German-Poland basin and in the Paris basin. Organic matter may immobilise these metals and silica content influences metallic elements concentrations in soils. Natural processes of soil development, land management of agricultural soils and population density all together may be responsible for higher concentrations of W in the soils of Netherlands Germany, Belgium, Switzerland and northeast France which seems not related with Sn-W mineral provinces. Tin and tungsten are enriched in the Precambrian shields compared to the Caledonian shields soils in the northern countries, although in northern countries climatic conditions may play the most important role in these elements concentrations. Tin and tungsten and tin or tungsten alone or in association of precious metals, copper, uranium, niobium, beryllium, titanium altogether were extracted in 650 small or median size mines in Portugal. Except tin in Neves Corvo mine of the Iberian Pyrite Belt the rest of these mines occurred in the Variscides granitic intrusions region. Tin and tungsten concentrations are therefore well reflected in the northern Portugal soils. At the GEMAS density of sampling pollution and local natural phenomena are not reflected in mapping but this important province is well delimited.

Dynamic fragmentation of laser shock-melted tin: experiment and modelling

Energy Technology Data Exchange (ETDEWEB)

De Resseguier, T. [CNRS ENSMA, Lab Combust and Deton, F-86961 Futuroscope (France); Signor, L.; Dragon, A. [CNRS ENSMA, Mecan and Phys Mat Lab, F-86961 Futuroscope (France); Signor, L.; Roy, G. [CEA Valduc, 21 - Is-sur-Tille (France)

2010-07-01

Dynamic fragmentation of shock-loaded metals is an issue of considerable importance for both basic science and a variety of technological applications, such as pyrotechnics or inertial confinement fusion, the latter involving high energy laser irradiation of thin metallic shells. Whereas spall fracture in solid materials has been extensively studied for many years, little data can be found yet about the evolution of this phenomenon after partial or full melting on compression or on release. Here, we present an investigation of dynamic fragmentation in laser shock-melted tin, from the 'micro-spall' process (ejection of a cloud of fine droplets) occurring upon reflection of the compressive pulse from the target free surface, to the late rupture observed in the un-spalled melted layer (leading to the formation of larger spherical fragments). Experimental results consist of time-resolved velocity measurements and post-shock observations of recovered targets and fragments. They provide original information regarding the loss of tensile strength associated with melting, the cavitation mechanism likely to occur in the melted metal, the sizes of the subsequent fragments and their ejection velocities. A theoretical description based on an energetic approach adapted to the case of a liquid metal is implemented as a failure criterion in a one-dimensional hydro-code including a multi-phase equation of state for tin. The resulting predictions of the micro-spall process are compared with experimental data. In particular, the use of a new experimental technique to quantify the fragment size distributions leads to a much better agreement with theory than previously reported. Finally, a complementary approach focused on cavitation is proposed to evaluate the role of this phenomenon in the fragmentation of the melted metal. (authors)

A novel approach for the improvement of electrostatic behaviour of physically doped TFET using plasma formation and shortening of gate electrode with hetero-gate dielectric

Science.gov (United States)

Soni, Deepak; Sharma, Dheeraj; Aslam, Mohd.; Yadav, Shivendra

2018-04-01

This article presents a new device configuration to enhance current drivability and suppress negative conduction (ambipolar conduction) with improved RF characteristics of physically doped TFET. Here, we used a new approach to get excellent electrical characteristics of hetero-dielectric short gate source electrode TFET (HD-SG SE-TFET) by depositing a metal electrode of 5.93 eV work function over the heavily doped source (P+) region. Deposition of metal electrode induces the plasma (thin layer) of holes under the Si/HfO2 interface due to work function difference of metal and semiconductor. Plasma layer of holes is advantageous to increase abruptness as well as decrease the tunneling barrier at source/channel junction for attaining higher tunneling rate of charge carriers (i.e., electrons), which turns into 86.66 times higher ON-state current compared with the conventional physically doped TFET (C-TFET). Along with metal electrode deposition, gate electrode is under-lapped for inducing asymmetrical concentration of charge carriers in the channel region, which is helpful for widening the tunneling barrier width at the drain/channel interface. Consequently, HD-SG SE-TFET shows suppression of ambipolar behavior with reduction in gate-to-drain capacitance which is beneficial for improvement in RF performance. Furthermore, the effectiveness of hetero-gate dielectric concept has been used for improving the RF performance. Furthermore, reliability of C-TFET and proposed structures has been confirmed in term of linearity.

Structural studies of supported tin catalysts

Science.gov (United States)

Nava, Noel; Viveros, Tomás

1999-11-01

Tin oxide was supported on aluminium oxide, titanium oxide, magnesium oxide and silicon oxide, and the resulting interactions between the components in the prepared samples and after reduction were characterized by Mössbauer spectroscopy. It was observed that in the oxide state, tin is present as SnO2 on alumina, magnesia and silica, but on titania tin occupies Ti sites in the structure. After hydrogen treatment at high temperatures, tin is reduced from Sn(4) to Sn(2) on alumina and titania; it is reduced from Sn(4) to Sn(0) on silica, and is practically not reduced on magnesia. These results reveal the degree of interaction between tin and the different supports studied.

Structural studies of supported tin catalysts

International Nuclear Information System (INIS)

Nava, Noel; Viveros, Tomas

1999-01-01

Tin oxide was supported on aluminium oxide, titanium oxide, magnesium oxide and silicon oxide, and the resulting interactions between the components in the prepared samples and after reduction were characterized by Moessbauer spectroscopy. It was observed that in the oxide state, tin is present as SnO 2 on alumina, magnesia and silica, but on titania tin occupies Ti sites in the structure. After hydrogen treatment at high temperatures, tin is reduced from Sn(4) to Sn(2) on alumina and titania; it is reduced from Sn(4) to Sn(0) on silica, and is practically not reduced on magnesia. These results reveal the degree of interaction between tin and the different supports studied

Molecular dynamics simulations of ejecta production from sinusoidal tin surfaces under supported and unsupported shocks

Science.gov (United States)

Wu, Bao; Wu, FengChao; Zhu, YinBo; Wang, Pei; He, AnMin; Wu, HengAn

2018-04-01

Micro-ejecta, an instability growth process, occurs at metal/vacuum or metal/gas interface when compressed shock wave releases from the free surface that contains surface defects. We present molecular dynamics (MD) simulations to investigate the ejecta production from tin surface shocked by supported and unsupported waves with pressures ranging from 8.5 to 60.8 GPa. It is found that the loading waveforms have little effect on spike velocity while remarkably affect the bubble velocity. The bubble velocity of unsupported shock loading remains nonzero constant value at late time as observed in experiments. Besides, the time evolution of ejected mass in the simulations is compared with the recently developed ejecta source model, indicating the suppressed ejection of unmelted or partial melted materials. Moreover, different reference positions are chosen to characterize the amount of ejecta under different loading waveforms. Compared with supported shock case, the ejected mass of unsupported shock case saturates at lower pressure. Through the analysis on unloading path, we find that the temperature of tin sample increases quickly from tensile stress state to zero pressure state, resulting in the melting of bulk tin under decaying shock. Thus, the unsupported wave loading exhibits a lower threshold pressure causing the solid-liquid phase transition on shock release than the supported shock loading.

The development of latent fingerprints by zinc oxide and tin oxide nanoparticles prepared by precipitation technique

Science.gov (United States)

Luthra, Deepali; Kumar, Sacheen

2018-05-01

Fingerprints are the very important evidence at the crime scene which must be developed clearly with shortest duration of time to solve the case. Metal oxide nanoparticles could be the mean to develop the latent fingerprints. Zinc oxide and Tin Oxide Nanoparticles were prepared by using chemical precipitation technique which were dried and characterized by X-ray diffraction, UV-Visible spectroscopy and FTIR. The size of zinc oxide crystallite was found to be 14.75 nm with minimum reflectance at 360 nm whereas tin oxide have the size of 90 nm and reflectance at minimum level 321 nm. By using these powdered samples on glass, plastic and glossy cardboard, latent fingerprints were developed. Zinc oxide was found to be better candidate than tin oxide for the fingerprint development on all the three types of substrates.

Electroresistance effect in gold thin film induced by ionic-liquid-gated electric double layer

International Nuclear Information System (INIS)

Nakayama, Hiroyasu; Ohtani, Takashi; Fujikawa, Yasunori; Ando, Kazuya; Saitoh, Eiji; Ye, Jianting; Iwasa, Yoshihiro

2012-01-01

Electroresistance effect was detected in a metallic thin film using ionic-liquid-gated electric-double-layer transistors (EDLTs). We observed reversible modulation of the electric resistance of a Au thin film. In this system, we found that an electric double layer works as a nanogap capacitor with 27 (-25) MV cm -1 of electric field by applying only 1.7 V of positive (negative) gate voltage. The experimental results indicate that the ionic-liquid-gated EDLT technique can be used for controlling the surface electronic states on metallic systems. (author)

Cylindrical gate all around Schottky barrier MOSFET with insulated shallow extensions at source/drain for removal of ambipolarity: a novel approach

Science.gov (United States)

Kumar, Manoj; Pratap, Yogesh; Haldar, Subhasis; Gupta, Mridula; Gupta, R. S.

2017-12-01

In this paper TCAD-based simulation of a novel insulated shallow extension (ISE) cylindrical gate all around (CGAA) Schottky barrier (SB) MOSFET has been reported, to eliminate the suicidal ambipolar behavior (bias-dependent OFF state leakage current) of conventional SB-CGAA MOSFET by blocking the metal-induced gap states as well as unwanted charge sharing between source/channel and drain/channel regions. This novel structure offers low barrier height at the source and offers high ON-state current. The I ON/I OFF of ISE-CGAA-SB-MOSFET increases by 1177 times and offers steeper subthreshold slope (~60 mV/decade). However a little reduction in peak cut off frequency is observed and to further improve the cut-off frequency dual metal gate architecture has been employed and a comparative assessment of single metal gate, dual metal gate, single metal gate with ISE, and dual metal gate with ISE has been presented. The improved performance of Schottky barrier CGAA MOSFET by the incorporation of ISE makes it an attractive candidate for CMOS digital circuit design. The numerical simulation is performed using the ATLAS-3D device simulator.

The Aharonov-Bohm effect in a side-gated graphene ring

International Nuclear Information System (INIS)

Huefner, Magdalena; Molitor, Francoise; Jacobsen, Arnhild; Pioda, Alessandro; Stampfer, Christoph; Ensslin, Klaus; Ihn, Thomas

2010-01-01

We investigate the magnetoresistance of a side-gated ring structure etched out of single-layer graphene. We observe Aharonov-Bohm oscillations with about 5% visibility. We are able to change the relative phases of the wave functions in the interfering paths and induce phase jumps of π in the Aharonov-Bohm oscillations by changing the voltage applied to the side gate or the back gate. The observed data can be interpreted within existing models for 'dirty metals'.

Comparison of electron transmittances and tunneling currents in an anisotropic TiNx/HfO2/SiO2/p-Si(100) metal-oxide-semiconductor (MOS) capacitor calculated using exponential- and Airy-wavefunction approaches and a transfer matrix method

International Nuclear Information System (INIS)

Noor, Fatimah A.; Abdullah, Mikrajuddin; Sukirno; Khairurrijal

2010-01-01

Analytical expressions of electron transmittance and tunneling current in an anisotropic TiN x /HfO 2 /SiO 2 /p-Si(100) metal-oxide-semiconductor (MOS) capacitor were derived by considering the coupling of transverse and longitudinal energies of an electron. Exponential and Airy wavefunctions were utilized to obtain the electron transmittance and the electron tunneling current. A transfer matrix method, as a numerical approach, was used as a benchmark to assess the analytical approaches. It was found that there is a similarity in the transmittances calculated among exponential- and Airy-wavefunction approaches and the TMM at low electron energies. However, for high energies, only the transmittance calculated by using the Airy-wavefunction approach is the same as that evaluated by the TMM. It was also found that only the tunneling currents calculated by using the Airy-wavefunction approach are the same as those obtained under the TMM for all range of oxide voltages. Therefore, a better analytical description for the tunneling phenomenon in the MOS capacitor is given by the Airy-wavefunction approach. Moreover, the tunneling current density decreases as the titanium concentration of the TiN x metal gate increases because the electron effective mass of TiN x decreases with increasing nitrogen concentration. In addition, the mass anisotropy cannot be neglected because the tunneling currents obtained under the isotropic and anisotropic masses are very different. (semiconductor devices)

Complementary and bipolar regimes of resistive switching in TiN/HfO{sub 2}/TiN stacks grown by atomic-layer deposition

Energy Technology Data Exchange (ETDEWEB)

Egorov, K.V.; Kirtaev, R.V.; Markeev, A.M.; Zablotskiy, A.V. [Moscow Institute of Physics and Technology, Institutskii per. 9, 141700, Dolgoprudny (Russian Federation); Lebedinskii, Yu.Yu.; Matveyev, Yu.A.; Zenkevich, A.V. [Moscow Institute of Physics and Technology, Institutskii per. 9, 141700, Dolgoprudny (Russian Federation); National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoye shosse 31, 115409, Moscow (Russian Federation); Orlov, O.M. [Scientific Research Institute of Molecular Electronics and Plant ' ' Micron' ' , 124462, Zelenograd (Russian Federation)

2015-04-01

Atomic-layer deposition (ALD) technique in combination with in vacuo X-ray photoelectron spectroscopy (XPS) analysis has been successfully employed to obtain fully ALD-grown planar TiN/HfO{sub 2}/TiN metal-insulator-metal structures for resistive random access memory (ReRAM) memory elements. In vacuo XPS analysis of ALD-grown TiN/HfO{sub 2}/TiN stacks reveals the presence of the ultrathin oxidized layers consisting of TiON (∝0.5 nm) and TiO{sub 2} (∝0.6 nm) at the bottom TiN/HfO{sub 2} interface (i); the nonoxidized TiN at the top HfO{sub 2}/TiN interface (ii); the oxygen deficiency in the HfO{sub 2} layer does not exceed the XPS detection limit (iii). Electroformed ALD TiN/HfO{sub 2}/TiN stacks reveal both conventional bipolar and complementary types of resistive switching. In the complementary resistive switching regime, each programming sequence is terminated by a reset operation, leaving the TiN/HfO{sub 2}/TiN stack in a high-resistance state. The observed feature can avoid detrimental leaky paths during successive reading operation, which is useful in the passive ReRAM arrays without a selector element. The bipolar regime of resistive switching is found to reveal the gradual character of the SET and RESET switching processes. Long-term potentiation and depression tests performed on ALD-grown TiN/HfO{sub 2}/TiN stacks indicate that they can be used as electronic synapse devices for the implementation of emerging neuromorphic computation systems. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Polymer-electrolyte-gated nanowire synaptic transistors for neuromorphic applications

Science.gov (United States)

Zou, Can; Sun, Jia; Gou, Guangyang; Kong, Ling-An; Qian, Chuan; Dai, Guozhang; Yang, Junliang; Guo, Guang-hua

2017-09-01

Polymer-electrolytes are formed by dissolving a salt in polymer instead of water, the conducting mechanism involves the segmental motion-assisted diffusion of ion in the polymer matrix. Here, we report on the fabrication of tin oxide (SnO2) nanowire synaptic transistors using polymer-electrolyte gating. A thin layer of poly(ethylene oxide) and lithium perchlorate (PEO/LiClO4) was deposited on top of the devices, which was used to boost device performances. A voltage spike applied on the in-plane gate attracts ions toward the polymer-electrolyte/SnO2 nanowire interface and the ions are gradually returned after the pulse is removed, which can induce a dynamic excitatory postsynaptic current in the nanowire channel. The SnO2 synaptic transistors exhibit the behavior of short-term plasticity like the paired-pulse facilitation and self-adaptation, which is related to the electric double-effect regulation. In addition, the synaptic logic functions and the logical function transformation are also discussed. Such single SnO2 nanowire-based synaptic transistors are of great importance for future neuromorphic devices.

Sensitivity, selectivity and stability of tin oxide nanostructures on large area arrays of microhotplates

Science.gov (United States)

Panchapakesan, Balaji; Cavicchi, Richard; Semancik, Steve; DeVoe, Don L.

2006-01-01

In this paper, the sensitivity, stability and selectivity of nanoparticle engineered tin oxide (SnO2) are reported, for microhotplate chemical sensing applications. 16 Å of metals such as nickel, cobalt, iron, copper and silver were selectively evaporated onto each column of the microhotplate array. Following evaporation, the microhotplates were heated to 500 °C and SnO2 was deposited on top of the microhotplates using a self-aligned chemical vapour deposition process. Scanning electron microscopy characterization revealed control of SnO2 nanostructures in the range of 20-121 nm. Gas sensing in seven different hydrocarbons revealed that metal nanoparticles that helped in producing faster nucleation of SnO2 resulted in smaller grain size and higher sensitivity. Sensitivity as a function of concentration and grain size is addressed for tin oxide nanostructures. Smaller grain sizes resulted in higher sensitivity of tin oxide nanostructures. Temperature programmed sensing of the devices yielded shape differences in the response between air and methanol, illustrating selectivity. Spiderweb plots were used to monitor the materials programmed selectivity. The shape differences between different gases in spiderweb plots illustrate materials selectivity as a powerful mapping approach for monitoring selectivity in various gases. Continuous monitoring in 80 ppm methanol yielded stable sensor response for more than 200 h. This comprehensive study illustrates the use of a nanoparticle engineering approach for sensitive, selective and stable gas sensing applications.

Near interface traps in SiO{sub 2}/4H-SiC metal-oxide-semiconductor field effect transistors monitored by temperature dependent gate current transient measurements

Energy Technology Data Exchange (ETDEWEB)

Fiorenza, Patrick; La Magna, Antonino; Vivona, Marilena; Roccaforte, Fabrizio [Consiglio Nazionale delle Ricerche-Istituto per la Microelettronica e Microsistemi (CNR-IMM), Strada VIII 5, Zona Industriale 95121 Catania (Italy)

2016-07-04

This letter reports on the impact of gate oxide trapping states on the conduction mechanisms in SiO{sub 2}/4H-SiC metal-oxide-semiconductor field effect transistors (MOSFETs). The phenomena were studied by gate current transient measurements, performed on n-channel MOSFETs operated in “gate-controlled-diode” configuration. The measurements revealed an anomalous non-steady conduction under negative bias (V{sub G} > |20 V|) through the SiO{sub 2}/4H-SiC interface. The phenomenon was explained by the coexistence of a electron variable range hopping and a hole Fowler-Nordheim (FN) tunnelling. A semi-empirical modified FN model with a time-depended electric field is used to estimate the near interface traps in the gate oxide (N{sub trap} ∼ 2 × 10{sup 11} cm{sup −2}).

Evolution of interfacial Fermi level in In{sub 0.53}Ga{sub 0.47}As/high-κ/TiN gate stacks

Energy Technology Data Exchange (ETDEWEB)

Carr, Adra; Rozen, John; Frank, Martin M.; Ando, Takashi; Cartier, Eduard A.; Kerber, Pranita; Narayanan, Vijay; Haight, Richard [IBM T. J. Watson Research Center, P.O. Box 218, Yorktown Heights, New York 10598 (United States)

2015-07-06

The net charge state was probed of metal-oxide-semiconductor gate stacks consisting of In{sub 0.53}Ga{sub 0.47}As /high-κ dielectric/5 nm TiN, for both Al{sub 2}O{sub 3} and HfO{sub 2} dielectrics, via investigation of band bending at the InGaAs/high-κ interface. Using pump-probe photoelectron spectroscopy, changes to band bending were studied for each sequential layer deposited onto the InGaAs substrate and subsequent annealing up to 600 °C. Two behavioral regions were observed in annealing studies: (1) a lower temperature (<350 °C) region, attributed to changes at the high-κ/TiN interface, and (2) a higher temperature region (> 350 °C), associated with a net positive charge increase within the oxide. These band bending measurements delineate the impact of processing steps inherently inaccessible via capacitance-voltage electrical characterization.

Transparent conductive electrodes of mixed TiO2−x–indium tin oxide for organic photovoltaics

KAUST Repository

Lee, Kyu-Sung; Lim, Jong-Wook; Kim, Han-Ki; Alford, T. L.; Jabbour, Ghassan E.

2012-01-01

A transparent conductive electrode of mixed titanium dioxide (TiO2−x)–indium tin oxide (ITO) with an overall reduction in the use of indium metal is demonstrated. When used in organic photovoltaicdevices based on bulk heterojunction photoactive

Rare earth elements leaching from Tin slag using Acid Chloride after Alkaline fusion process

International Nuclear Information System (INIS)

Kurnia Trinopiawan; Budi Yuli Ani; June Mellawati; Mohammad Zaki Mubarok

2016-01-01

Tin slag, a waste product from tin smelting process, has a potency to be utilized further by extracting the valuable metals inside, such as rare earth elements(REE). The objective of this study is to determine the optimum leaching condition of REE from tin slag after alkali fusion. Silica structure in slag is causing the direct leaching uneffectively. Therefore, pre-treatment step using alkali fusion is required to break the structure of silica and to increase the porosity of slag. Fusion is conducted in 2 hours at 700°C, with ratio of natrium hydroxide (NaOH) : slag = 2 : 1. Later, frit which is leached by water then leached by chloride acid to dissolve REE. As much as 87,5% of REE is dissolved at 2 M on chloride acid (HCl) concentration, in 40°C temperature, -325 mesh particle size, 15 g/100 ml of S/L, 150 rpm of agitation speed, and 5 minutes of leaching time. (author)

Side-gate modulation effects on high-quality BN-Graphene-BN nanoribbon capacitors

International Nuclear Information System (INIS)

Wang, Yang; Chen, Xiaolong; Ye, Weiguang; Wu, Zefei; Han, Yu; Han, Tianyi; He, Yuheng; Cai, Yuan; Wang, Ning

2014-01-01

High-quality BN-Graphene-BN nanoribbon capacitors with double side-gates of graphene have been experimentally realized. The double side-gates can effectively modulate the electronic properties of graphene nanoribbon capacitors. By applying anti-symmetric side-gate voltages, we observed significant upward shifting and flattening of the V-shaped capacitance curve near the charge neutrality point. Symmetric side-gate voltages, however, only resulted in tilted upward shifting along the opposite direction of applied gate voltages. These modulation effects followed the behavior of graphene nanoribbons predicted theoretically for metallic side-gate modulation. The negative quantum capacitance phenomenon predicted by numerical simulations for graphene nanoribbons modulated by graphene side-gates was not observed, possibly due to the weakened interactions between the graphene nanoribbon and side-gate electrodes caused by the Ga + beam etching process

Design of an experiment for the production of a foamed tin sample

Science.gov (United States)

Wernimont, E.

1986-01-01

One of the major experiments in the GAS container is concerned with the experimental production of a foamed metal. A foamed metal is one that contains a significant amount of gas bubbles suspended in its solid volume. Purdue's GAS team proposes to do this with the help of a solid zinc carbonate that gives off carbon dioxide at high temperatures. Because of low energy requirements, the metal used for this experiment is tin. It is hoped that the use of near zero environment will keep the suspended bubbles more uniform than in an Earth based process, hence not depleting the physical strength of the material as greatly as is observed on Earth.

Effects of Y incorporation in TaON gate dielectric on electrical performance of GaAs metal-oxide-semiconductor capacitor

Energy Technology Data Exchange (ETDEWEB)

Liu, Li Ning; Choi, Hoi Wai; Lai, Pui To [Department of Electrical and Electronic Engineering, The University of Hong Kong (China); Xu, Jing Ping [School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan (China)

2016-09-15

In this study, GaAs metal-oxide-semiconductor (MOS) capacitors using Y-incorporated TaON as gate dielectric have been investigated. Experimental results show that the sample with a Y/(Y + Ta) atomic ratio of 27.6% exhibits the best device characteristics: high k value (22.9), low interfacestate density (9.0 x 10{sup 11} cm{sup -2} eV{sup -1}), small flatband voltage (1.05 V), small frequency dispersion and low gate leakage current (1.3 x 10{sup -5}A/cm{sup 2} at V{sub fb} + 1 V). These merits should be attributed to the complementary properties of Y{sub 2}O{sub 3} and Ta{sub 2}O{sub 5}:Y can effectively passivate the large amount of oxygen vacancies in Ta{sub 2}O{sub 5}, while the positively-charged oxygen vacancies in Ta{sub 2}O{sub 5} are capable of neutralizing the effects of the negative oxide charges in Y{sub 2}O{sub 3}. This work demonstrates that an appropriate doping of Y content in TaON gate dielectric can effectively improve the electrical performance for GaAs MOS devices. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Implementation of a funnel-and-gate remediation system

International Nuclear Information System (INIS)

O'Brien, K.; Keyes, G.; Sherman, N.

1997-01-01

A funnel-and-gate trademark system incorporating activated carbon was deemed the most attractive remediation method for an active lumber mill in the western United States. Petroleum hydrocarbons, chlorinated solvents, pentachlorophenol, and tetrachlorophenol were detected in on-site groundwater samples. The shallow aquifer consists of a heterogeneous mixture of marine deposits and artificial fill, underlain by low-permeability siltstones and mudstone. In the funnel-and-gate trademark system, a low-permeability cutoff wall was installed to funnel groundwater flow to a smaller area (a open-quotes gateclose quotes) where a passive below-grade treatment system treats the plume as it flows through the gate. Groundwater flow modeling focused on the inhomogeneities of the aquifer and the spatial relationship between gate(s) and barrier walls. The gate design incorporates several factors, including contaminant concentration, flow rate, and time between carbon changeouts. To minimize back pressure and maximize residence time, each gate was designed using 1.25-meter (4-foot) diameter corrugated metal pipe filled with a 1.25-meter (4-foot) thick bed of activated carbon. The configuration will allow water to flow through the treatment gates without pumps. The installed system is 190 meters (625 feet) long and treats approximately 76 L/min (20 gpm) during the winter months

Bimodal gate-dielectric deposition for improved performance of AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors

International Nuclear Information System (INIS)

Pang Liang; Kim, Kyekyoon

2012-01-01

A bimodal deposition scheme combining radiofrequency magnetron sputtering and plasma enhanced chemical vapour deposition (PECVD) is proposed as a means for improving the performance of GaN-based metal-oxide-semiconductor high-electron-mobility transistors (MOSHEMTs). High-density sputtered-SiO 2 is utilized to reduce the gate leakage current and enhance the breakdown voltage while low-density PECVD-SiO 2 is employed to buffer the sputtering damage and further increase the drain current by engineering the stress-induced-polarization. Thus-fabricated MOSHEMT exhibited a low leakage current of 4.21 × 10 -9 A mm -1 and high breakdown voltage of 634 V for a gate-drain distance of 6 µm, demonstrating the promise of bimodal-SiO 2 deposition scheme for the development of GaN-based MOSHEMTs for high-power application. (paper)

Characterization of some tin-contained ancient glass beads found in China by means of SEM-EDS and raman spectroscopy.

Science.gov (United States)

Li, Qinghui; Liu, Song; Su, Bomin; Zhao, Hongxia; Fu, Qiang; Dong, Junqing

2013-02-01

A total of nine tin-contained ancient glass beads were characterized by a combination of scanning electron microscopy coupled with energy-dispersive X-ray spectrometry and Raman spectroscopy. These glass beads dated from 1st century BC to 10th century AD were excavated from the Xinjiang and Guangxi provinces of China. Two kinds of tin-based opacifiers/colorants included crystalline cassiterite (SnO(2)) and lead-tin yellow types II were first found in these soda lime glass beads. The tentative chronology of the tin-based opacifiers/colorants used in ancient glasses from China and the West was compared. In addition, several transition metal ions colorants were also found in these beads. The detailed study of the glassy matrices, crystalline inclusions, and the microstructural heterogeneities for these glass beads has revealed some valuable information to trace the possible making technology and provenances. Copyright © 2012 Wiley Periodicals, Inc.

Electrochemical dissolution of tin in methanesulphonic acid solutions

NARCIS (Netherlands)

de Greef, R.A.T.; Janssen, L.J.J.

2001-01-01

High-rate electroplating of tin on a moving steel strip is generally carried out in cells with dimensionally stable anodes. To obtain a matt tin deposit a concentrated acidic tin methanesulphonate solution containing a small concentration of sulphuric acid is used. The concentrated tin

Influence of gate recess on the electronic characteristics of β-Ga2O3 MOSFETs

Science.gov (United States)

Lv, Yuanjie; Mo, Jianghui; Song, Xubo; He, Zezhao; Wang, Yuangang; Tan, Xin; Zhou, Xingye; Gu, Guodong; Guo, Hongyu; Feng, Zhihong

2018-05-01

Gallium oxide (Ga2O3) metal-oxide-semiconductor field-effect transistors (MOSFETs) were fabricated with gate recess depths of 110 nm and 220 nm, respectively. The gate recess was formed by dry plasma etching with Cr metal as the mask. The fabricated devices with a 25-nm HfO2 gate dielectric both showed a low off-state drain current of about 1.8 × 10-10 A/mm. The effects of recess depth on the electronic characteristics of Ga2O3 MOSFETs were investigated. Upon increasing the recess depth from 110 nm to 220 nm, the saturated drain current decreased from 20.7 mA/mm to 2.6 mA/mm, while the threshold voltage moved increased to +3 V. Moreover, the breakdown voltage increased from 122 V to 190 V. This is mainly because the inverted-trapezoidal gate played the role of a gate-field plate, which suppressed the peak electric field close to the gate.

Surface passivation function of indium-tin-oxide-based nanorod structural sensors

International Nuclear Information System (INIS)

Lin, Tzu-Shun; Lee, Ching-Ting; Lee, Hisn-Ying; Lin, Chih-Chien

2012-01-01

Employing self-shadowing traits of an oblique-angle electron-beam deposition system, various indium tin oxide (ITO) nanorod arrays were deposited on a silicon substrate and used as extended-gate field-effect-transistor (EGFET) pH sensors. The length and morphology of the deposited ITO nanorod arrays could be changed and controlled under different deposition conditions. The ITO nanorod structural EGFET pH sensors exhibited high sensing performances owing to the larger sensing surface area. The sensitivity of the pH sensors with 150-nm-length ITO nanorod arrays was 53.96 mV/pH. By using the photoelectrochemical treatment of the ITO nanorod arrays, the sensitivity of the pH sensors with 150-nm-length passivated ITO nanorod arrays was improved to 57.21 mV/pH.

First heats of cerium solution in liquid aluminium, gallium, indium, tin, lead and bismuth

International Nuclear Information System (INIS)

Yamshchikov, L.F.; Lebedev, V.A.; Nichkov, I.F.; Raspopin, S.P.; Shein, V.G.

1983-01-01

Cerium solution heats in liquid alluminium, gallium, indium, tin, lead and bismuth are determined in high temperature mixing calorimeter with an isothermal shell. The statistical analysis carried out proves that values of cerium solution heat in fusible metals obtained by the methods of electric motive forces and calorimety give a satisfactory agreement

Exact matrix treatment of statistical mechanical lattice model of adsorption induced gate opening in metal-organic frameworks

International Nuclear Information System (INIS)

Dunne, Lawrence J; Manos, George

2015-01-01

Here we present a statistical mechanical lattice model which is exactly solvable using a matrix method and allows treatment of adsorption induced gate opening structural transformations of metal-organic frameworks which are nanoporous materials with exceptional adsorption properties. Modelling of these structural changes presents a serious theoretical challenge when the solid and gas species are treated in an even handed way. This exactly solvable model complements other simulation based approaches. The methodology presented here highlights the competition between the potential for adsorption and the energy required for structural transition as a driving force for the features in the adsorption isotherms. (paper)

Molecular dynamics simulations of ejecta production from sinusoidal tin surfaces under supported and unsupported shocks

Directory of Open Access Journals (Sweden)

Bao Wu

2018-04-01

Full Text Available Micro-ejecta, an instability growth process, occurs at metal/vacuum or metal/gas interface when compressed shock wave releases from the free surface that contains surface defects. We present molecular dynamics (MD simulations to investigate the ejecta production from tin surface shocked by supported and unsupported waves with pressures ranging from 8.5 to 60.8 GPa. It is found that the loading waveforms have little effect on spike velocity while remarkably affect the bubble velocity. The bubble velocity of unsupported shock loading remains nonzero constant value at late time as observed in experiments. Besides, the time evolution of ejected mass in the simulations is compared with the recently developed ejecta source model, indicating the suppressed ejection of unmelted or partial melted materials. Moreover, different reference positions are chosen to characterize the amount of ejecta under different loading waveforms. Compared with supported shock case, the ejected mass of unsupported shock case saturates at lower pressure. Through the analysis on unloading path, we find that the temperature of tin sample increases quickly from tensile stress state to zero pressure state, resulting in the melting of bulk tin under decaying shock. Thus, the unsupported wave loading exhibits a lower threshold pressure causing the solid-liquid phase transition on shock release than the supported shock loading.

GaN MOSHEMT employing HfO2 as a gate dielectric with partially etched barrier

Science.gov (United States)

Han, Kefeng; Zhu, Lin

2017-09-01

In order to suppress the gate leakage current of a GaN high electron mobility transistor (GaN HEMT), a GaN metal-oxide-semiconductor high electron mobility transistor (MOSHEMT) is proposed, in which a metal-oxide-semiconductor gate with high-dielectric-constant HfO2 as an insulating dielectric is employed to replace the traditional GaN HEMT Schottky gate. A 0.5 μm gate length GaN MOSHEMT was fabricated based on the proposed structure, the {{{Al}}}0.28{{{Ga}}}0.72{{N}} barrier layer is partially etched to produce a higher transconductance without deteriorating the transport characteristics of the two-dimensional electron gas in the channel, the gate dielectric is HfO2 deposited by atomic layer deposition. Current-voltage characteristics and radio frequency characteristics are obtained after device preparation, the maximum current density of the device is 900 mA mm-1, the source-drain breakdown voltage is 75 V, gate current is significantly suppressed and the forward gate voltage swing range is about ten times higher than traditional GaN HEMTs, the GaN MOSHEMT also demonstrates radio frequency characteristics comparable to traditional GaN HEMTs with the same gate length.

Kinetics of solid-phase in ion exchange on tin hydrogen phosphate

International Nuclear Information System (INIS)

Kislitsyn, M.N.; Ketsko, V.A.; Yaroslavtsev, A.B.

2004-01-01

Solid state reactions in mixture of tin hydrogen phosphate and alkali metal (M=Na, K, Cs) chlorides have been studied both in the mode of polythermal heating and at a fixed temperature, using data of X-ray phase and thermogravimetric analyses. In the range 400-750 Deg C solid state ion exchange reactions occur in the systems studied and yield mono-- and dialkali phosphates MHSn(PO 4 ) 2 and M 2 Sn(PO 4 ) 2 . Counter diffusion coefficients for alkali metal cations and protons in the matrices of compositions MHSn(PO 4 ) 2 and M 2 Sn(PO 4 ) 2 have been determined [ru

First-principles simulations of the leakage current in metal-oxide-semiconductor structures caused by oxygen vacancies in HfO2 high-K gate dielectric

International Nuclear Information System (INIS)

Mao, L.F.; Wang, Z.O.

2008-01-01

HfO 2 high-K gate dielectric has been used as a new gate dielectric in metal-oxide-semiconductor structures. First-principles simulations are used to study the effects of oxygen vacancies on the tunneling current through the oxide. A level which is nearly 1.25 eV from the bottom of the conduction band is introduced into the bandgap due to the oxygen vacancies. The tunneling current calculations show that the tunneling currents through the gate oxide with different defect density possess the typical characteristic of stress-induced leakage current. Further analysis shows that the location of oxygen vacancies will have a marked effect on the tunneling current. The largest increase in the tunneling current caused by oxygen vacancies comes about at the middle oxide field when defects are located at the middle of the oxide. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Tin-antimony oxide oxidation catalysts

Energy Technology Data Exchange (ETDEWEB)

Berry, Frank J. [Open University, Department of Chemistry (United Kingdom)

1998-12-15

Tin-antimony oxide catalysts for the selective oxidation of hydrocarbons have been made by precipitation techniques. The dehydration of the amorphous dried precipitate by calcination at increasingly higher temperatures induces the crystallisation of a rutile-related tin dioxide-type phase and the segregation of antimony oxides which volatilise at elevated temperatures. The rutile-related tin dioxide-type phase contains antimony(V) in the bulk and antimony(III) in the surface. Specific catalytic activity for the oxidative dehydrogenation of butene to butadiene is associated with materials with large concentrations of antimony(III) in the surface.

High performance Ω-gated Ge nanowire MOSFET with quasi-metallic source/drain contacts.

Science.gov (United States)

Burchhart, T; Zeiner, C; Hyun, Y J; Lugstein, A; Hochleitner, G; Bertagnolli, E

2010-10-29

Ge nanowires (NWs) about 2 µm long and 35 nm in diameter are grown heteroepitaxially on Si(111) substrates in a hot wall low-pressure chemical vapor deposition (LP-CVD) system using Au as a catalyst and GeH(4) as precursor. Individual NWs are contacted to Cu pads via e-beam lithography, thermal evaporation and lift-off techniques. Self-aligned and atomically sharp quasi-metallic copper-germanide source/drain contacts are achieved by a thermal activated phase formation process. The Cu(3)Ge segments emerge from the Cu contact pads through axial diffusion of Cu which was controlled in situ by SEM, thus the active channel length of the MOSFET is adjusted without any restrictions from a lithographic process. Finally the conductivity of the channel is enhanced by Ga(+) implantation leading to a high performance Ω-gated Ge-NW MOSFET with saturation currents of a few microamperes.

Transfer-free graphene synthesis on sapphire by catalyst metal agglomeration technique and demonstration of top-gate field-effect transistors

International Nuclear Information System (INIS)

Miyoshi, Makoto; Arima, Yukinori; Kubo, Toshiharu; Egawa, Takashi; Mizuno, Masaya; Soga, Tetsuo

2015-01-01

Transfer-free graphene synthesis was performed on sapphire substrates by using the catalyst metal agglomeration technique, and the graphene film quality was compared to that synthesized on sputtered SiO 2 /Si substrates. Raman scattering measurements indicated that the graphene film on sapphire has better structural qualities than that on sputtered SiO 2 /Si substrates. The cross-sectional transmission microscopic study also revealed that the film flatness was drastically improved by using sapphire substrates instead of sputtered SiO 2 /Si substrates. These quality improvements seemed to be due the chemical and thermal stabilities of sapphire. Top-gate field-effect transistors were fabricated using the graphene films on sapphire, and it was confirmed that their drain current can be modulated with applied gate voltages. The maximum field-effect mobilities were estimated to be 720 cm 2 /V s for electrons and 880 cm 2 /V s for holes, respectively

Transfer-free graphene synthesis on sapphire by catalyst metal agglomeration technique and demonstration of top-gate field-effect transistors

Energy Technology Data Exchange (ETDEWEB)

Miyoshi, Makoto, E-mail: miyoshi.makoto@nitech.ac.jp; Arima, Yukinori; Kubo, Toshiharu; Egawa, Takashi [Research Center for Nano Device and Advanced Materials, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Mizuno, Masaya [Research Center for Nano Device and Advanced Materials, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Department of Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Soga, Tetsuo [Department of Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

2015-08-17

Transfer-free graphene synthesis was performed on sapphire substrates by using the catalyst metal agglomeration technique, and the graphene film quality was compared to that synthesized on sputtered SiO{sub 2}/Si substrates. Raman scattering measurements indicated that the graphene film on sapphire has better structural qualities than that on sputtered SiO{sub 2}/Si substrates. The cross-sectional transmission microscopic study also revealed that the film flatness was drastically improved by using sapphire substrates instead of sputtered SiO{sub 2}/Si substrates. These quality improvements seemed to be due the chemical and thermal stabilities of sapphire. Top-gate field-effect transistors were fabricated using the graphene films on sapphire, and it was confirmed that their drain current can be modulated with applied gate voltages. The maximum field-effect mobilities were estimated to be 720 cm{sup 2}/V s for electrons and 880 cm{sup 2}/V s for holes, respectively.

Simulation of dual-gate SOI MOSFET with different dielectric layers

Science.gov (United States)

Yadav, Jyoti; Chaudhary, R.; Mukhiya, R.; Sharma, R.; Khanna, V. K.

2016-04-01

The paper presents the process design and simulation of silicon-on-insulator (SOI)-based dual-gate metal oxide field-effect transistor (DG-MOSFET) stacked with different dielectric layers on the top of gate oxide. A detailed 2D process simulation of SOI-MOSFETs and its electrical characterization has been done using SILVACO® TCAD tool. A variation in transconductance was observed with different dielectric layers, AlN-gate MOSFET having the highest tranconductance value as compared to other three dielectric layers (SiO2, Si3N4 and Al2O3).

Sedimentation rate and chronology of As and Zn in sediment of a recent former tin mining lake estimated using Pb-210 dating technique

International Nuclear Information System (INIS)

Zaharidah Abu Bakar; Ahmad Saat; Zaini Hamzah; Abdul Khalik Wood; Zaharudin Ahmad

2011-01-01

Sedimentation in lake occurred through run-off from the land surface and settles on the bottom lake. Past mining activities might enhance sedimentation process in the former tin mining lakes either through natural or human activities. Former tin mining lakes were suspected to have high sedimentation rate due undisturbed environment for almost 50 years. To estimate sedimentation rate and metals contamination in this lake, Pb-210 dating technique was used. Two sediments cores were sampled using gravity corer from a former tin mining lake then analyzed using alpha-spectrometry and Neutron Activation Analysis (NAA). From this study, the results showed the sedimentation rate for sediment cores S1 and S2 are 0.26 cm y -1 and 0.23 cmy -1 respectively. According to sediment chronological sequences, high concentrations of As and Zn in the upper layer indicated that human activities contributed to these metals contamination in the lake sediment. Sedimentation rate and metals contamination possibly due to recent anthropogenic activities around the lake such as human settlement, farming and agricultures activities since the ceased of mining activities a few decades ago. (author)

Measurements of void fraction in a water-molten tin system by X-ray absorption

International Nuclear Information System (INIS)

Baker, Michael C.; Bonazza, Riccardo; Corradini, Michael L.

1998-01-01

A facility has been developed to study the explosive interactions of gas-water injection into a molten tin pool. The experimental apparatus allows for variable nitrogen gas and water injection into the base of a steel tank containing up to 25 kg of molten tin. Due to the opaque nature of the molten metal-gas-water mixture and steel tank, a visualization and measurement technique using continuous high energy x-rays had to be developed. Visualization of the multiphase mixture can be done at 220 Hz with 256x256 pixel resolution or at 30 Hz with 480x1128 pixel resolution. These images are stored digitally and subsequently processed to obtain two dimensional mappings of the chordal average void fraction in the mixture. The image processing method has been used to measure void fraction in experiments that did not include water in the injection mixture. This work includes a comparison to previous studies of integral void fraction data in pools of molten metal with gas injection. (author)

Rf reactive sputtering of indium-tin-oxide films

International Nuclear Information System (INIS)

Tvarozek, V.; Novotny, I.; Harman, R.; Kovac, J.

1986-01-01

Films of indium-tin-oxide (ITO) have been deposited by rf reactive diode sputtering of metallic InSn alloy targets, or ceramic ITO targets, in an Ar and Ar+0 2 atmosphere. Electrical as well as optical properties of ITO films were controlled by varying sputtering parameters and by post-deposition heat-treatment in Ar, H 2 , N 2 , H 2 +N 2 ambients. The ITO films exhibited low resistivity approx. 2 x 10 -4 Ω cm, high transmittance approx. 90% in the visible spectral region and high reflectance approx. 80% in the near infra-red region. (author)

Thickness engineering of atomic layer deposited Al2O3 films to suppress interfacial reaction and diffusion of Ni/Au gate metal in AlGaN/GaN HEMTs up to 600 °C in air

Science.gov (United States)

Suria, Ateeq J.; Yalamarthy, Ananth Saran; Heuser, Thomas A.; Bruefach, Alexandra; Chapin, Caitlin A.; So, Hongyun; Senesky, Debbie G.

2017-06-01

In this paper, we describe the use of 50 nm atomic layer deposited (ALD) Al2O3 to suppress the interfacial reaction and inter-diffusion between the gate metal and semiconductor interface, to extend the operation limit up to 600 °C in air. Suppression of diffusion is verified through Auger electron spectroscopy (AES) depth profiling and X-ray diffraction (XRD) and is further supported with electrical characterization. An ALD Al2O3 thin film (10 nm and 50 nm), which functions as a dielectric layer, was inserted between the gate metal (Ni/Au) and heterostructure-based semiconductor material (AlGaN/GaN) to form a metal-insulator-semiconductor high electron mobility transistor (MIS-HEMT). This extended the 50 nm ALD Al2O3 MIS-HEMT (50-MIS) current-voltage (Ids-Vds) and gate leakage (Ig,leakage) characteristics up to 600 °C. Both, the 10 nm ALD Al2O3 MIS-HEMT (10-MIS) and HEMT, failed above 350 °C, as evidenced by a sudden increase of approximately 50 times and 5.3 × 106 times in Ig,leakage, respectively. AES on the HEMT revealed the formation of a Ni-Au alloy and Ni present in the active region. Additionally, XRD showed existence of metal gallides in the HEMT. The 50-MIS enables the operation of AlGaN/GaN based electronics in oxidizing high-temperature environments, by suppressing interfacial reaction and inter-diffusion of the gate metal with the semiconductor.

Achieving high carrier mobility exceeding 70 cm2/Vs in amorphous zinc tin oxide thin-film transistors

Science.gov (United States)

Kim, Sang Tae; Shin, Yeonwoo; Yun, Pil Sang; Bae, Jong Uk; Chung, In Jae; Jeong, Jae Kyeong

2017-09-01

This paper proposes a new defect engineering concept for low-cost In- and Ga-free zinc tin oxide (ZTO) thin-film transistors (TFTs). This concept is comprised of capping ZTO films with tantalum (Ta) and a subsequent modest thermal annealing treatment at 200 °C. The Ta-capped ZTO TFTs exhibited a remarkably high carrier mobility of 70.8 cm2/Vs, low subthreshold gate swing of 0.18 V/decade, threshold voltage of -1.3 V, and excellent ION/OFF ratio of 2 × 108. The improvement (> two-fold) in the carrier mobility compared to the uncapped ZTO TFT can be attributed to the effective reduction of the number of adverse tailing trap states, such as hydroxyl groups or oxygen interstitial defects, which stems from the scavenging effect of the Ta capping layer on the ZTO channel layer. Furthermore, the Ta-capped ZTO TFTs showed excellent positive and negative gate bias stress stabilities. [Figure not available: see fulltext.

Epitaxial integration of CoFe2O4 thin films on Si (001) surfaces using TiN buffer layers

Science.gov (United States)

Prieto, Pilar; Marco, José F.; Prieto, José E.; Ruiz-Gomez, Sandra; Perez, Lucas; del Real, Rafael P.; Vázquez, Manuel; de la Figuera, Juan

2018-04-01

Epitaxial cobalt ferrite thin films with strong in-plane magnetic anisotropy have been grown on Si (001) substrates using a TiN buffer layer. The epitaxial films have been grown by ion beam sputtering using either metallic, CoFe2, or ceramic, CoFe2O4, targets. X-ray diffraction (XRD) and Rutherford spectrometry (RBS) in random and channeling configuration have been used to determine the epitaxial relationship CoFe2O4 [100]/TiN [100]/Si [100]. Mössbauer spectroscopy, in combination with XRD and RBS, has been used to determine the composition and structure of the cobalt ferrite thin films. The TiN buffer layer induces a compressive strain in the cobalt ferrite thin films giving rise to an in-plane magnetic anisotropy. The degree of in-plane anisotropy depends on the lattice mismatch between CoFe2O4 and TiN, which is larger for CoFe2O4 thin films grown on the reactive sputtering process with ceramic targets.

Properties of hard alloys on the basis of WC-Co with the additives of nanodisperse TiN

International Nuclear Information System (INIS)

Ordanyan, S.S.; Andronova, T.E.; Vladimirova, M.A.; Pantelejev, I.B.; Zalite, I.

2001-01-01

The addition of nanodisperse titanium nitride (specific surface area of 20 - 30 m 2 /g, medium diameter of grains of 50 - 100 nm) to the starting hard alloy WC-Co in the stage of wet grinding allows to get some advantages: the growth of WC grains is retarded by the nanoparticles of TiN, being as a barrier for the process of secondary crystallization, and the toughness of hard alloy is being increased due to the formation of finely dispersed structure; the exploitation characteristics of cutting instruments are increased due to the volume alloying by means of titanium nitride having a decreased adhesion to the treated metal and decreased coefficient of friction; the formation of diffusion porosity is being eliminated due to the small size of TiN during the unavoidable dissolution of WC in TiN. (author)

Colorimetric properties of TiN coating implanted by aluminum

Energy Technology Data Exchange (ETDEWEB)

Zhou, Q.G. [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)]. E-mail: zhouqg99@mails.tsinghua.edu.cn; Bai, X.D. [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Xue, X.Y. [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Ling, Y.H. [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Chen, X.W. [Department of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Xu, J. [Beijing Great Wall Ti-Gold Corporation, Beijing 100095 (China); Wang, D.R. [Beijing Great Wall Ti-Gold Corporation, Beijing 100095 (China)

2005-04-05

TiN coating was prepared by cathodic arc deposition and implanted aluminum using a metal vacuum vapor arc ion source with doses ranging from 5 x 10{sup 16} to 2 x 10{sup 17} ions/cm{sup 2}. The purpose of this work was to determine the dependence of the colorimetric properties of TiN films on the implanting conditions, especially by the aluminum ion implantation. The colorimetry of coatings was evaluated quantitatively in terms of CIE L * a * b *. The color coordinate values L *, a *, and b * provide a numerical representation of the color of the surface. With the dose increasing, the surface color has no obvious change but the surface turns brighter, and a * as well as b * values all decline. The X-ray diffraction patterns showed that the aluminum implantation induced a slight shift of diffraction peaks. X-ray photoemission spectroscopy was employed to analyze the surface valence states. The oxygen in surface top layer does not decrease a * and b * values, it partially combined with nitrogen.

Defect Engineering and Interface Phenomena in Tin Oxide

KAUST Repository

Albar, Arwa

2017-04-05

The advance in transparent electronics requires high-performance transparent conducting oxide materials. The microscopic properties of these materials are sensitive to the presence of defects and interfaces and thus fundamental understanding is required for materials engineering. In this thesis, first principles density functional theory is used to investigate the possibility of tuning the structural, electronic and magnetic properties of tin oxide by means of defects and interfaces. Our aim is to reveal unique properties and the parameters to control them as well as to explain the origin of unique phenomena in oxide materials. The stability of native defect in tin monoxide (SnO) under strain is investigated using formation energy calculations. We find that the conductivity (which is controlled by native defects) can be switched from p-type to either n-type or undoped semiconducting by means of applied pressure. We then target inducing magnetism in SnO by 3d transition metal doping. We propose that V doping is efficient to realize spin polarization at high temperature. We discuss different tin oxide interfaces. Metallic states are found to form at the SnO/SnO2 interface with electronic properties that depend on the interface terminations. The origin of these states is explained in terms of charge transfer caused by chemical bonding and band alignment. For the SnO/SnO2 heterostructure, we observe the formation of a two dimensional hole gas at the interface, which is surprising as it cannot be explained by the standard polar catastrophe model. Thus, we propose a charge density discontinuity model to explain our results. The model can be generalized to other polar-polar interfaces. Motivated by technological applications, the electronic and structural properties of the MgO (100)/SnO2 (110) interface are investigated. Depending on the interface termination, we observe the formation of a two dimensional electron gas or spin polarized hole gas. Aiming to identify further

Structural, optical and electrical properties of tin oxide thin films for application as a wide band gap semiconductor

Energy Technology Data Exchange (ETDEWEB)

Sethi, Riti; Ahmad, Shabir; Aziz, Anver; Siddiqui, Azher Majid, E-mail: amsiddiqui@jmi.ac.in [Department of Physics, Jamia Millia Islamia, New Delhi-110025 (India)

2015-08-28

Tin oxide (SnO) thin films were synthesized using thermal evaporation technique. Ultra pure metallic tin was deposited on glass substrates using thermal evaporator under high vacuum. The thickness of the tin deposited films was kept at 100nm. Subsequently, the as-deposited tin films were annealed under oxygen environment for a period of 3hrs to obtain tin oxide films. To analyse the suitability of the synthesized tin oxide films as a wide band gap semiconductor, various properties were studied. Structural parameters were studied using XRD and SEM-EDX. The optical properties were studied using UV-Vis Spectrophotometry and the electrical parameters were calculated using the Hall-setup. XRD and SEM confirmed the formation of SnO phase. Uniform texture of the film can be seen through the SEM images. Presence of traces of unoxidised Sn has also been confirmed through the XRD spectra. The band gap calculated was around 3.6eV and the optical transparency around 50%. The higher value of band gap and lower value of optical transparency can be attributed to the presence of unoxidised Sn. The values of resistivity and mobility as measured by the Hall setup were 78Ωcm and 2.92cm{sup 2}/Vs respectively. The reasonable optical and electrical parameters make SnO a suitable candidate for optoelectronic and electronic device applications.

Temperature dependence of trapping effects in metal gates/Al2O3/InGaAs stacks

Science.gov (United States)

Palumbo, F.; Pazos, S.; Aguirre, F.; Winter, R.; Krylov, I.; Eizenberg, M.

2017-06-01

The influence of the temperature on Metal Gate/Al2O3/n-InGaAs stacks has been studied by means of capacitance-voltage (C-V) hysteresis and flat band voltage as function of both negative and positive stress fields. It was found that the de-trapping effect decreases at low-temperature, indicating that the de-trapping of trapped electrons from oxide traps may be performed via Al2O3/InGaAs interface defects. The dependence of the C-V hysteresis on the stress field at different temperatures in our InGaAs stacks can be explained in terms of the defect spatial distribution. An oxide defect distribution can be found very close to the metal gate/Al2O3 interface. On the other side, the Al2O3/InGaAs interface presents defects distributed from the interface into the bulk of the oxide, showing the influence of InGaAs on Al2O3 in terms of the spatial defect distribution. At the present, he is a research staff of the National Council of Science and Technology (CONICET), working in the National Commission of Atomic Energy (CNEA) in Buenos Aires, Argentina, well embedded within international research collaboration. Since 2008, he is Professor at the National Technological University (UTN) in Buenos Aires, Argentina. Dr. Palumbo has received research fellowships from: Marie Curie Fellowship within the 7th European Community Framework Programme, Abdus Salam International Centre for Theoretical Physics (ICTP) Italy, National Council of Science and Technology (CONICET) Argentina, and Consiglio Nazionale delle Ricerche (CNR) Italy. He is also a frequent scientific visitor of academic institutions as IMM-CNR-Italy, Minatec Grenoble-France, the Autonomous University of Barcelona-Spain, and the Israel Institute of Technology-Technion. He has authored and co-authored more than 50 papers in international conferences and journals.

Role of Electrical Double Layer Structure in Ionic Liquid Gated Devices.

Science.gov (United States)

Black, Jennifer M; Come, Jeremy; Bi, Sheng; Zhu, Mengyang; Zhao, Wei; Wong, Anthony T; Noh, Joo Hyon; Pudasaini, Pushpa R; Zhang, Pengfei; Okatan, Mahmut Baris; Dai, Sheng; Kalinin, Sergei V; Rack, Philip D; Ward, Thomas Zac; Feng, Guang; Balke, Nina

2017-11-22

Ionic liquid gating of transition metal oxides has enabled new states (magnetic, electronic, metal-insulator), providing fundamental insights into the physics of strongly correlated oxides. However, despite much research activity, little is known about the correlation of the structure of the liquids in contact with the transition metal oxide surface, its evolution with the applied electric potential, and its correlation with the measured electronic properties of the oxide. Here, we investigate the structure of an ionic liquid at a semiconducting oxide interface during the operation of a thin film transistor where the electrical double layer gates the device using experiment and theory. We show that the transition between the ON and OFF states of the amorphous indium gallium zinc oxide transistor is accompanied by a densification and preferential spatial orientation of counterions at the oxide channel surface. This process occurs in three distinct steps, corresponding to ion orientations, and consequently, regimes of different electrical conductivity. The reason for this can be found in the surface charge densities on the oxide surface when different ion arrangements are present. Overall, the field-effect gating process is elucidated in terms of the interfacial ionic liquid structure, and this provides unprecedented insight into the working of a liquid gated transistor linking the nanoscopic structure to the functional properties. This knowledge will enable both new ionic liquid design as well as advanced device concepts.

Near-thermal limit gating in heavily doped III-V semiconductor nanowires using polymer electrolytes

Science.gov (United States)

Ullah, A. R.; Carrad, D. J.; Krogstrup, P.; Nygârd, J.; Micolich, A. P.

2018-02-01

Doping is a common route to reducing nanowire transistor on-resistance but it has limits. A high doping level gives significant loss in gate performance and ultimately complete gate failure. We show that electrolyte gating remains effective even when the Be doping in our GaAs nanowires is so high that traditional metal-oxide gates fail. In this regime we obtain a combination of subthreshold swing and contact resistance that surpasses the best existing p -type nanowire metal-oxide semiconductor field-effect transistors (MOSFETs). Our subthreshold swing of 75 mV/dec is within 25 % of the room-temperature thermal limit and comparable with n -InP and n -GaAs nanowire MOSFETs. Our results open a new path to extending the performance and application of nanowire transistors, and motivate further work on improved solid electrolytes for nanoscale device applications.

Decrease in effective electron mobility in the channel of a metal-oxide-semiconductor transistor as the gate length is decreased

International Nuclear Information System (INIS)

Frantsuzov, A. A.; Boyarkina, N. I.; Popov, V. P.

2008-01-01

Effective electron mobility μ eff in channels of metal-oxide-semiconductor transistors with a gate length L in the range of 3.8 to 0.34 μm was measured; the transistors were formed on wafers of the silicon-oninsulator type. It was found that μ eff decreases as L is decreased. It is shown that this decrease can be accounted for by the effect of series resistances of the source and drain only if it is assumed that there is a rapid increase in these resistances as the gate voltage is decreased. This assumption is difficult to substantiate. A more realistic model is suggested; this model accounts for the observed decrease in μ eff as L is decreased. The model implies that zones with a mobility lower than that in the middle part of the channel originate at the edges of the gate. An analysis shows that, in this case, the plot of the dependence of 1/μ eff on 1/L should be linear, which is exactly what is observed experimentally. The use of this plot makes it possible to determine both the electron mobility μ 0 in the middle part of the channel and the quantity A that characterizes the zones with lowered mobility at the gate’s edges.

Chemical gating of epitaxial graphene through ultrathin oxide layers.

Science.gov (United States)

Larciprete, Rosanna; Lacovig, Paolo; Orlando, Fabrizio; Dalmiglio, Matteo; Omiciuolo, Luca; Baraldi, Alessandro; Lizzit, Silvano

2015-08-07

We achieved a controllable chemical gating of epitaxial graphene grown on metal substrates by exploiting the electrostatic polarization of ultrathin SiO2 layers synthesized below it. Intercalated oxygen diffusing through the SiO2 layer modifies the metal-oxide work function and hole dopes graphene. The graphene/oxide/metal heterostructure behaves as a gated plane capacitor with the in situ grown SiO2 layer acting as a homogeneous dielectric spacer, whose high capacity allows the Fermi level of graphene to be shifted by a few hundreds of meV when the oxygen coverage at the metal substrate is of the order of 0.5 monolayers. The hole doping can be finely tuned by controlling the amount of interfacial oxygen, as well as by adjusting the thickness of the oxide layer. After complete thermal desorption of oxygen the intrinsic doping of SiO2 supported graphene is evaluated in the absence of contaminants and adventitious adsorbates. The demonstration that the charge state of graphene can be changed by chemically modifying the buried oxide/metal interface hints at the possibility of tuning the level and sign of doping by the use of other intercalants capable of diffusing through the ultrathin porous dielectric and reach the interface with the metal.

Tin Oxide Nanoparticles: Synthesis, Characterization and Study their Particle Size at Different Current Density

Directory of Open Access Journals (Sweden)

Karzan A. Omar

2013-11-01

Full Text Available Tin oxide nanoparticles are prepared by electrochemical reduction method using tetrapropylammonium bromide (TPAB and tetrabutylammonium bromide (TBAB as structure directing agent in an organic medium viz. tetrahydrofuran (THF and acetonitrile (ACN in 4:1 ratio by optimizing current density and molar concentration of the ligand. The reduction process takes place under an inert atmosphere of nitrogen over a period of 2 h. Such nanoparticles are prepared by using a simple electrolysis cell in which the sacrificial anode as a commercially available in tin metal sheet and platinum (inert sheet act as a cathode. The parameters such as current density, solvent polarity, distance between electrodes and concentration of stabilizers are used to control the size of nanoparticles. The synthesized tin oxide nanoparticles are characterized by using UV–Visible, FT-IR and SEM–EDS analysis techniques. UV-Visible spectroscopy has revealed the optical band gap to be 4.13, 4.16 and 4.24 ev for (8, 10 and 12 mA/cm2 and the effect of current density on theirs particle size, respectively.

Scaling the Serialization of MOSFETs by Magnetically Coupling Their Gate Electrodes

DEFF Research Database (Denmark)

Dimopoulos, Emmanouil; Munk-Nielsen, Stig

2013-01-01

More than twenty years of thorough research on the serialization of power semiconductor switches, like the Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) or the Insulated Gate Bipolar Transistor (IGBT), have resulted into several different stacking concepts; all aiming towards...... the establishment of a high-efficient, high-voltage, fast-switching device. Among the prevailing stacking approaches lies the gate balancing core technique, which, in its initial form, demonstrated very good performance in strings of high-power IGBT modules, by magnetically coupling their gate electrodes. Recently...

Synthesis and Mössbauer spectroscopy of formal tin(II) dichloride and dihydride species supported by Lewis acids and bases.

Science.gov (United States)

Al-Rafia, S M Ibrahim; Shynkaruk, Olena; McDonald, Sean M; Liew, Sean K; Ferguson, Michael J; McDonald, Robert; Herber, Rolfe H; Rivard, Eric

2013-05-06

(119)Sn Mössbauer spectroscopy was performed on a series of formal Sn(II) dichloride and dihydride adducts bound by either carbon- or phosphorus-based electron pair donors. Upon binding electron-withdrawing metal pentacarbonyl units to the tin centers in LB·SnCl2·M(CO)5 (LB = Lewis base; M = Cr or W), a significant decrease in isomer shift (IS) was noted relative to the unbound Sn(II) complexes, LB·SnCl2, consistent with removal of nonbonding s-electron density from tin upon forming Sn-M linkages (M = Cr and W). Interestingly, when the nature of the Lewis base in the series LB·SnCl2·W(CO)5 was altered, very little change in the IS values was noted, implying that the LB-Sn bonds were constructed with tin-based orbitals of large p-character (as supported by prior theoretical studies). In addition, variable temperature Mössbauer measurements were used to determine the mean displacement of the tin atoms in the solid state, a parameter that can be correlated with the degree of covalent bonding involving tin in these species.

The role of collisional tectonics in the metallogeny of the Central Andean tin belt [rapid communication

Science.gov (United States)

Mlynarczyk, Michael S. J.; Williams-Jones, Anthony E.

2005-12-01

The Inner Arc of the Central Andes, broadly corresponding to the Eastern Cordillera, is the location of a rich Tertiary and Triassic Sn-W-(Ag-base metal) metallogenic province, commonly referred to as the Bolivian tin belt. We propose that the Tertiary metallogeny, which generated most of the tin ores, was a direct consequence of discrete "collisions" between the South American plate and the Nazca slab and sub-slab mantle, during the ongoing Andean orogeny. Evidence supporting this proposal include: (1) the coincidence of the tin province and the Inner Arc in a marked "hump" in the Andean orogen, which may represent tectonic indentation; (2) the symmetry of the tin province with respect to the Bolivian orocline, the axis of which corresponds to the direction of highest compression; (3) the relative symmetry of the magmatism and tin mineralization with respect to this axis; (4) the concurrent timing of mineralization and compressional pulses; (5) the similar host rock geochemistry and ore lead isotope data, testifying to a common crustal reservoir; and (6) the striking similarity of the igneous suites, associated with the ore deposits to those from "typical" collisional orogens. A number of studies have called upon a persistent tin anomaly to explain the metallogeny of the region. We propose, instead, that the latter is better explained by periodic compressional interaction between the Farallon/Nazca oceanic plate and the South American continent. This led to the generation of peraluminous magmas, which during fractional crystallization exsolved the fluids responsible for the voluminous Sn-W mineralization.

CMOS Active-Pixel Image Sensor With Simple Floating Gates

Science.gov (United States)

Fossum, Eric R.; Nakamura, Junichi; Kemeny, Sabrina E.

1996-01-01

Experimental complementary metal-oxide/semiconductor (CMOS) active-pixel image sensor integrated circuit features simple floating-gate structure, with metal-oxide/semiconductor field-effect transistor (MOSFET) as active circuit element in each pixel. Provides flexibility of readout modes, no kTC noise, and relatively simple structure suitable for high-density arrays. Features desirable for "smart sensor" applications.

The relevance of electrostatics for scanning-gate microscopy

International Nuclear Information System (INIS)

Schnez, S; Guettinger, J; Stampfer, C; Ensslin, K; Ihn, T

2011-01-01

Scanning-probe techniques have been developed to extract local information from a given physical system. In particular, conductance maps obtained by means of scanning-gate microscopy (SGM), where a conducting tip of an atomic-force microscope is used as a local and movable gate, seem to present an intuitive picture of the underlying physical processes. Here, we argue that the interpretation of such images is complex and not very intuitive under certain circumstances: scanning a graphene quantum dot (QD) in the Coulomb-blockaded regime, we observe an apparent shift of features in scanning-gate images as a function of gate voltages, which cannot be a real shift of the physical system. Furthermore, we demonstrate the appearance of more than one set of Coulomb rings arising from the graphene QD. We attribute these effects to screening between the metallic tip and the gates. Our results are relevant for SGM on any kind of nanostructure, but are of particular importance for nanostructures that are not covered with a dielectric, e.g. graphene or carbon nanotube structures.

Conversion electron Moessbauer spectroscopic studies on the chemical states of surface layers of corroded tin plates and tin-coated iron plates

International Nuclear Information System (INIS)

Kato, Akinori; Endo, Kazutoyo; Sano, Hirotoshi

1980-01-01

By means of the conversion electron Moessbauer spectroscopy (CEMS), we studied surface layers of ''tin'' plates and tin-coated iron plates corroded by various acids. Transmission Moessbauer spectra and X-ray diffraction patterns were also measured. Metastannic acid was formed, when the ''tin'' plate was corroded by nitric acid solution. In corrosion by phosphoric acid solution, the X-ray diffractometry revealed the formation of tin(IV) pyrophosphate. In corrosion by various organic acid solutions, the formation of oxides was identified by the 119 Sn CEMS, but not by the X-ray diffractometry because of the too thin corrosion layer. In corrosion of tin-coated iron plates, maleic acid, malonic acid, formic acid, and oxalic acid were used. It was determined by CEMS that the corrosion products caused by these acids were tin(IV) oxides, although they could not be identified by the X-ray diffractometry. CEMS also confirmed that the surface of uncorroded tin-coated iron plate was already oxidized by air. Colorimetric determinations of Sn and Fe dissolved from tin-coated iron plates to various acid solutions confirmed that maleic acid had the strongest corrosion effect among the organic acids studied. (author)

C-V characterization of Schottky- and MIS-gate SiGe/Si HEMT structures

International Nuclear Information System (INIS)

Onojima, Norio; Kasamatsu, Akihumi; Hirose, Nobumitsu; Mimura, Takashi; Matsui, Toshiaki

2008-01-01

Electrical properties of Schottky- and metal-insulator-semiconductor (MIS)-gate SiGe/Si high electron mobility transistors (HEMTs) were investigated with capacitance-voltage (C-V) measurements. The MIS-gate HEMT structure was fabricated using a SiN gate insulator formed by catalytic chemical vapor deposition (Cat-CVD). The Cat-CVD SiN thin film (5 nm) was found to be an effective gate insulator with good gate controllability and dielectric properties. We previously investigated device characteristics of sub-100-nm-gate-length Schottky- and MIS-gate HEMTs, and reported that the MIS-gate device had larger maximum drain current density and transconductance (g m ) than the Schottky-gate device. The radio frequency (RF) measurement of the MIS-gate device, however, showed a relatively lower current gain cutoff frequency f T compared with that of the Schottky-gate device. In this study, C-V characterization of the MIS-gate HEMT structure demonstrated that two electron transport channels existed, one at the SiGe/Si buried channel and the other at the SiN/Si surface channel

C-V characterization of Schottky- and MIS-gate SiGe/Si HEMT structures

Energy Technology Data Exchange (ETDEWEB)

Onojima, Norio [National Institute of Information and Communications Technology (NICT), Koganei, Tokyo 184-8795 (Japan)], E-mail: nonojima@nict.go.jp; Kasamatsu, Akihumi; Hirose, Nobumitsu [National Institute of Information and Communications Technology (NICT), Koganei, Tokyo 184-8795 (Japan); Mimura, Takashi [National Institute of Information and Communications Technology (NICT), Koganei, Tokyo 184-8795 (Japan); Fujitsu Laboratories Ltd., Atsugi, Kanagawa 243-0197 (Japan); Matsui, Toshiaki [National Institute of Information and Communications Technology (NICT), Koganei, Tokyo 184-8795 (Japan)

2008-07-30

Electrical properties of Schottky- and metal-insulator-semiconductor (MIS)-gate SiGe/Si high electron mobility transistors (HEMTs) were investigated with capacitance-voltage (C-V) measurements. The MIS-gate HEMT structure was fabricated using a SiN gate insulator formed by catalytic chemical vapor deposition (Cat-CVD). The Cat-CVD SiN thin film (5 nm) was found to be an effective gate insulator with good gate controllability and dielectric properties. We previously investigated device characteristics of sub-100-nm-gate-length Schottky- and MIS-gate HEMTs, and reported that the MIS-gate device had larger maximum drain current density and transconductance (g{sub m}) than the Schottky-gate device. The radio frequency (RF) measurement of the MIS-gate device, however, showed a relatively lower current gain cutoff frequency f{sub T} compared with that of the Schottky-gate device. In this study, C-V characterization of the MIS-gate HEMT structure demonstrated that two electron transport channels existed, one at the SiGe/Si buried channel and the other at the SiN/Si surface channel.

Directly smelted lead-tin alloys: A historical perspective

Science.gov (United States)

Dube, R. K.

2010-08-01

This paper discusses evidence related to the genesis and occurrence of mixed lead-tin ore deposit consisting of cassiterite and the secondary minerals formed from galena. These evidences belong to a very long time period ranging from pre-historic to as late as the nineteenth century a.d. This type of mixed ore deposits was smelted to prepare lead-tin alloys. The composition of the alloy depended on the composition of the starting ore mixture. A nineteenth century evidence for the production of directly smelted lead-tin alloys in southern Thailand is discussed. A unique and rather uncommon metallurgical terminology in Sanskrit language— Nāgaja—was introduced in India for the tin recovered from impure lead. This suggests that Indians developed a process for recovering tin from lead-tin alloys, which in all probability was based on the general principle of fire refining. It has been shown that in the context of India the possibility of connection between the word Nāgaja and the directly smelted lead-tin alloys cannot be ruled out.

Effect of gate dielectrics on the performance of p-type Cu2O TFTs processed at room temperature

KAUST Repository

Al-Jawhari, Hala A.

2013-12-01

Single-phase Cu2O films with p-type semiconducting properties were successfully deposited by reactive DC magnetron sputtering at room temperature followed by post annealing process at 200°C. Subsequently, such films were used to fabricate bottom gate p-channel Cu2O thin film transistors (TFTs). The effect of using high-κ SrTiO3 (STO) as a gate dielectric on the Cu2O TFT performance was investigated. The results were then compared to our baseline process which uses a 220 nm aluminum titanium oxide (ATO) dielectric deposited on a glass substrate coated with a 200 nm indium tin oxide (ITO) gate electrode. We found that with a 150 nm thick STO, the Cu2O TFTs exhibited a p-type behavior with a field-effect mobility of 0.54 cm2.V-1.s-1, an on/off ratio of around 44, threshold voltage equaling -0.62 V and a sub threshold swing of 1.64 V/dec. These values were obtained at a low operating voltage of -2V. The advantages of using STO as a gate dielectric relative to ATO are discussed. © (2014) Trans Tech Publications, Switzerland.

AlGaN/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistor with Polarized P(VDF-TrFE) Ferroelectric Polymer Gating

Science.gov (United States)

Liu, Xinke; Lu, Youming; Yu, Wenjie; Wu, Jing; He, Jiazhu; Tang, Dan; Liu, Zhihong; Somasuntharam, Pannirselvam; Zhu, Deliang; Liu, Wenjun; Cao, Peijiang; Han, Sun; Chen, Shaojun; Seow Tan, Leng

2015-01-01

Effect of a polarized P(VDF-TrFE) ferroelectric polymer gating on AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) was investigated. The P(VDF-TrFE) gating in the source/drain access regions of AlGaN/GaN MOS-HEMTs was positively polarized (i.e., partially positively charged hydrogen were aligned to the AlGaN surface) by an applied electric field, resulting in a shift-down of the conduction band at the AlGaN/GaN interface. This increases the 2-dimensional electron gas (2-DEG) density in the source/drain access region of the AlGaN/GaN heterostructure, and thereby reduces the source/drain series resistance. Detailed material characterization of the P(VDF-TrFE) ferroelectric film was also carried out using the atomic force microscopy (AFM), X-ray Diffraction (XRD), and ferroelectric hysteresis loop measurement. PMID:26364872

Toxicology of inorganic tin

International Nuclear Information System (INIS)

Burba, J.V.

1982-01-01

Tin(II) or stannous ion as a reducing agent is important in nuclear medicine because it is an essential component and common denominator for many in vivo radiodiagnostic agents, commonly called kits for the preparation of radiopharmaceuticals. This report is intended to alert nuclear medicine community regarding the wide range of biological effects that the stannous ion is capable of producing, and is a review of a large number of selected publications on the toxicological potential of tin(II)

Synthesis, structure, and thermal properties of soluble hydrazinium germanium(IV) and tin(IV) selenide salts.

Science.gov (United States)

Mitzi, David B

2005-05-16

The crystal structures of two hydrazinium-based germanium(IV) and tin(IV) selenide salts are determined. (N(2)H(5))(4)Ge(2)Se(6) (1) [I4(1)cd, a = 12.708(1) Angstroms, c = 21.955(2) Angstroms, Z = 8] and (N(2)H(4))(3)(N(2)H(5))(4)Sn(2)Se(6) (2) [P, a = 6.6475(6) Angstroms, b = 9.5474(9) Angstroms, c = 9.8830(10) Angstroms, alpha = 94.110(2) degrees, beta = 99.429(2) degrees, gamma = 104.141(2) degrees, Z = 1] each consist of anionic dimers of edge-sharing metal selenide tetrahedra, M(2)Se(6)(4-) (M = Ge or Sn), separated by hydrazinium cations and, for 2, additional neutral hydrazine molecules. Substantial hydrogen bonding exists among the hydrazine/hydrazinium molecules as well as between the hydrazinium cations and the selenide anions. Whereas the previously reported tin(IV) sulfide system, (N(2)H(5))(4)Sn(2)S(6), decomposes cleanly to microcrystalline SnS(2) when heated to 200 degrees C in an inert atmosphere, higher temperatures (>300 degrees C) are required to dissociate selenium from 1 and 2 for the analogous preparations of single-phase metal selenides. The metal chalcogenide salts are highly soluble in hydrazine, as well as in a variety of amines and DMSO, highlighting the potential usefulness of these compounds as precursors for the solution deposition of the corresponding metal chalcogenide films.

Uranium and plutonium extraction from fluoride melts by lithium-tin alloys

International Nuclear Information System (INIS)

Kashcheev, I.N.; Novoselov, G.P.; Zolotarev, A.B.

1975-01-01

Extraction of small amounts of uranium (12 wt. % concentration) and plutonium (less than 1.10sup(-10) % concentration) from lithium fluoride melts into the lithium-tin melts is studied. At an increase of temperature from 850 to 1150 deg the rate of process increases 2.5 times. At an increase of melting time the extraction rapidly enhances at the starting moment and than its rate reduces. Plutonium is extracted into the metallic phase for 120 min. (87-96%). It behaves analogously to uranium

Nanocrystalline SnO2 formation by oxygen ion implantation in tin thin films

Science.gov (United States)

Kondkar, Vidya; Rukade, Deepti; Kanjilal, Dinakar; Bhattacharyya, Varsha

2018-03-01

Metallic tin thin films of thickness 100 nm are deposited on fused silica substrates by thermal evaporation technique. These films are implanted with 45 keV oxygen ions at fluences ranging from 5 × 1015 to 5 × 1016 ions cm-2. The energy of the oxygen ions is calculated using SRIM in order to form embedded phases at the film-substrate interface. Post-implantation, films are annealed using a tube furnace for nanocrystalline tin oxide formation. These films are characterized using x-ray diffraction, Raman spectroscopy, UV-vis spectroscopy and photoluminescence spectroscopy. XRD and Raman spectroscopy studies reveal the formation of single rutile phase of SnO2. The size of the nanocrystallites formed decreases with an increase in the ion fluence. The nanocrystalline SnO2 formation is also confirmed by UV-vis and photoluminescence spectroscopy.

Characterization of tin selenides synthesized by high-energy milling

Directory of Open Access Journals (Sweden)

Marcela Achimovičová

2011-12-01

Full Text Available Tin selenides SnSeX (x=1,2 were synthesized from tin and selenium powder precursors by high-energy milling in the planetary ballmill Pulverisette 6 (Fritsch, Germany. The orthorhombic tin selenide SnSe and the hexagonal tin diselenide SnSe2 phases were formed after4 min and 5 min of milling, respectively. Specific surface area of both selenides increased with increasing time of mechanochemicalsynthesis. The particle size distribution analysis demonstrated that the synthesized products contain agglomerated selenide particlesconsisting of numerous idiomorphic tin selenide crystals, measuring from 2 to more than 100 nm in diameter, which were also documentedby TEM. UV-Vis spectrophotometry confirmed that tin selenide particles do not behave as quantum dots.

Ingestion risks of metals in groundwater based on TIN model and dose-response assessment - A case study in the Xiangjiang watershed, central-south China

International Nuclear Information System (INIS)

Chai, Liyuan; Wang, Zhenxing; Wang, Yunyan; Yang, Zhihui; Wang, Haiying; Wu, Xie

2010-01-01

Groundwater samples were collected in the Xiangjiang watershed in China from 2002 to 2008 to analyze concentrations of arsenic, cadmium, chromium, copper, iron, lead, mercury, manganese, and zinc. Spatial and seasonal trends of metal concentrations were then discussed. Combined with geostatistics, an ingestion risk assessment of metals in groundwater was performed using the dose-response assessment method and the triangulated irregular network (TIN) model. Arsenic concentration in groundwater had a larger variation from year to year, while the variations of other metal concentrations were minor. Meanwhile, As concentrations in groundwater over the period of 2002-2004 were significantly higher than that over the period of 2005-2007, indicating the improvement of groundwater quality within the later year. The hazard index (HI) in 2002 was also significantly higher than that in 2005, 2006, 2007 and 2008. Moreover, more than 80% of the study area recorded an HI of more than 1.0 for children, suggesting that some people will experience deleterious health effects from drinking groundwater in the Xiangjiang watershed. Arsenic and manganese were the largest contributors to human health risks (HHRs). This study highlights the value of long-term health risk evaluation and the importance of geographic information system (GIS) technologies in the assessment of watershed-scale human health risk.

Terahertz modulation based on surface plasmon resonance by self-gated graphene

Science.gov (United States)

Qian, Zhenhai; Yang, Dongxiao; Wang, Wei

2018-05-01

We theoretically and numerically investigate the extraordinary optical transmission through a terahertz metamaterial composed of metallic ring aperture arrays. The physical mechanism of different transmission peaks is elucidated to be magnetic polaritons or propagation surface plasmons with the help of surface current and electromagnetic field distributions at respective resonance frequencies. Then, we propose a high performance terahertz modulator based on the unique PSP resonance and combined with the metallic ring aperture arrays and a self-gated parallel-plate graphene capacitor. Because, to date, few researches have exhibited gate-controlled graphene modulation in terahertz region with low insertion losses, high modulation depth and low control voltage at room temperature. Here, we propose a 96% amplitude modulation with 0.7 dB insertion losses and ∼5.5 V gate voltage. Besides, we further study the absorption spectra of the modulator. When the transmission of modulator is very low, a 91% absorption can be achieved for avoiding damaging the source devices.

Role of Oxygen in Ionic Liquid Gating on Two-Dimensional Cr2Ge2Te6: A Non-oxide Material.

Science.gov (United States)

Chen, Yangyang; Xing, Wenyu; Wang, Xirui; Shen, Bowen; Yuan, Wei; Su, Tang; Ma, Yang; Yao, Yunyan; Zhong, Jiangnan; Yun, Yu; Xie, X C; Jia, Shuang; Han, Wei

2018-01-10

Ionic liquid gating can markedly modulate a material's carrier density so as to induce metallization, superconductivity, and quantum phase transitions. One of the main issues is whether the mechanism of ionic liquid gating is an electrostatic field effect or an electrochemical effect, especially for oxide materials. Recent observation of the suppression of the ionic liquid gate-induced metallization in the presence of oxygen for oxide materials suggests the electrochemical effect. However, in more general scenarios, the role of oxygen in the ionic liquid gating effect is still unclear. Here, we perform ionic liquid gating experiments on a non-oxide material: two-dimensional ferromagnetic Cr 2 Ge 2 Te 6 . Our results demonstrate that despite the large increase of the gate leakage current in the presence of oxygen, the oxygen does not affect the ionic liquid gating effect on  the channel resistance of Cr 2 Ge 2 Te 6 devices (ionic liquid gating is more effective on the modulation of the channel resistances compared to the back gating across the 300 nm thick SiO 2 .

Economical characteristics of base types of minerals. 1. Metallic minerals

International Nuclear Information System (INIS)

Khasanov, A.Kh.

1990-01-01

Metallic minerals is raw materials base of black and colour metallurgy. In this article of book author describes the group of black metals (iron, manganese, chromium), group of tempers (titanium, vanadium, nickel, cobalt, molybdenum, tungsten), colour metals (copper, lead, zinc, aluminium, tin, mercury, antimony, bismuth) and etc.

A split accumulation gate architecture for silicon MOS quantum dots

Science.gov (United States)

Rochette, Sophie; Rudolph, Martin; Roy, Anne-Marie; Curry, Matthew; Ten Eyck, Gregory; Dominguez, Jason; Manginell, Ronald; Pluym, Tammy; King Gamble, John; Lilly, Michael; Bureau-Oxton, Chloé; Carroll, Malcolm S.; Pioro-Ladrière, Michel

We investigate tunnel barrier modulation without barrier electrodes in a split accumulation gate architecture for silicon metal-oxide-semiconductor quantum dots (QD). The layout consists of two independent accumulation gates, one gate forming a reservoir and the other the QD. The devices are fabricated with a foundry-compatible, etched, poly-silicon gate stack. We demonstrate 4 orders of magnitude of tunnel-rate control between the QD and the reservoir by modulating the reservoir gate voltage. Last electron charging energies of app. 10 meV and tuning of the ST splitting in the range 100-200 ueV are observed in two different split gate layouts and labs. This work was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

One-step synthesis of 2D-layered carbon wrapped transition metal nitrides from transition metal carbides (MXenes) for supercapacitors with ultrahigh cycling stability.

Science.gov (United States)

Yuan, Wenyu; Cheng, Laifei; Wu, Heng; Zhang, Yani; Lv, Shilin; Guo, Xiaohui

2018-03-13

A novel one-step method to synthesize 2D carbon wrapped TiN (C@TiN) was proposed via using 2D metal carbides (MXenes) as precursors. This study provides a novel approach to synthesize carbon wrapped metal nitrides.

A radiochemical NAA method for the determination of tin, barium, copper and antimony- role of tin as an indicator for gun shot residues

International Nuclear Information System (INIS)

Chattopadhyay, N.; Basu, A.K.; Tripathi, A.B.R.; Rao, M.S.; Anil Kumar, S.; Parthasarathy, R.; Mathur, P.K.

1998-01-01

Metallic tin being present as impurity and hardening agent of lead bullet/shot, is expected to play an important role in forensic ballistics in matching of bullet lead specimens for establishment of commonness of origin and also as an additional parameter for characterisation of Gun Shot Residue (GSR). 121 Sn is a suitable radioisotope for quantification of the element at ppm level if it is separated in highest radiochemical purity. A sequential Radiochemical Neutron Activation Analysis (RNAA) procedure for its simultaneous determination along with trace levels of Ba, Cu and Sb has been developed and its applications in forensic science are described. (author)

Physical and electrical characteristics of AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors with rare earth Er2O3 as a gate dielectric

International Nuclear Information System (INIS)

Lin, Ray-Ming; Chu, Fu-Chuan; Das, Atanu; Liao, Sheng-Yu; Chou, Shu-Tsun; Chang, Liann-Be

2013-01-01

In this study, the rare earth erbium oxide (Er 2 O 3 ) was deposited using an electron beam onto an AlGaN/GaN heterostructure to fabricate metal-oxide-semiconductor high-electron-mobility transistors (MOS–HEMTs) that exhibited device performance superior to that of a conventional HEMT. Under similar bias conditions, the gate leakage currents of these MOS–HEMT devices were four orders of magnitude lower than those of conventional Schottky gate HEMTs. The measured sub-threshold swing (SS) and the effective trap state density (N t ) of the MOS–HEMT were 125 mV/decade and 4.3 × 10 12 cm −2 , respectively. The dielectric constant of the Er 2 O 3 layer in this study was 14, as determined through capacitance–voltage measurements. In addition, the gate–source reverse breakdown voltage increased from –166 V for the conventional HEMT to –196 V for the Er 2 O 3 MOS–HEMT. - Highlights: ► GaN/AlGaN/Er 2 O 3 metal-oxide semiconductor high electron mobility transistor ► Physical and electrical characteristics are presented. ► Electron beam evaporated Er 2 O 3 with excellent surface roughness ► Device exhibits reduced gate leakage current and improved I ON /I OFF ratio

Gas-controlled dynamic vacuum insulation with gas gate

Science.gov (United States)

Benson, D.K.; Potter, T.F.

1994-06-07

Disclosed is a dynamic vacuum insulation comprising sidewalls enclosing an evacuated chamber and gas control means for releasing hydrogen gas into a chamber to increase gas molecule conduction of heat across the chamber and retrieving hydrogen gas from the chamber. The gas control means includes a metal hydride that absorbs and retains hydrogen gas at cooler temperatures and releases hydrogen gas at hotter temperatures; a hydride heating means for selectively heating the metal hydride to temperatures high enough to release hydrogen gas from the metal hydride; and gate means positioned between the metal hydride and the chamber for selectively allowing hydrogen to flow or not to flow between said metal hydride and said chamber. 25 figs.

Solid-gate control of insulator to 2D metal transition at SrTiO3 surface

Science.gov (United States)

Schulman, Alejandro; Stoliar, Pablo; Kitoh, Ai; Rozenberg, Marcelo; Inoue, Isao H.

As miniaturization of the semiconductor transistor approaches its limit, semiconductor industries are facing a major challenge to extend information processing beyond what can be attainable by conventional Si-based transistors. Innovative combinations of new materials and new processing platforms are desired. Recent discovery of the 2D electron gas (2DEG) at the surface of SrTiO3 (STO) and its electrostatic control, have carried it to the top of promising materials to be utilized in innovative devices. We report an electrostatic control of the carrier density of the 2DEG formed at the channel of bilayer-gated STO field-effect devices. By applying a gate electric field at room temperature, its highly insulating channel exhibits a transition to metallic one. This transition is accompanied by non-monotonic voltage-gain transfer characteristic with both negative and positive slope regions and unexpected enhancement of the sheet carrier density. We will introduce a numerical model to rationalize the observed features in terms of the established physics of field-effect transistors and the physics of percolation. Furthermore, we have found a clear signature of a Kondo effect that arises due to the interaction between the dilute 2DEG and localized Ti 3d orbitals originated by oxygen vacancies near the channel. On leave from CIC nanoGUNE, Spain.

Preparation of textural lamellar tin deposits via electrodeposition

Science.gov (United States)

Wen, Xiaoyu; Pan, Xiaona; Wu, Libin; Li, Ruinan; Wang, Dan; Zhang, Jinqiu; Yang, Peixia

2017-06-01

Lamellar tin deposits were prepared by galvanostatical electroplating from the aqueous acidic-sulfate bath, with gelatin and benzalacetone dissolved in ethanol (ABA+EtOH) as additive, and their morphologies were investigated by scanning electron microscopy. Cathodic polarization curves revealed that the absorbability of ABA+EtOH on the cathode surface was higher than that of gelatin. X-ray diffraction analysis indicated preferred orientations of tin growth led to the formation of lamellar structure and distortion of tin lattice. The growth mechanism of lamellar tin was also discussed.

High Mobility Thin Film Transistors Based on Amorphous Indium Zinc Tin Oxide

Directory of Open Access Journals (Sweden)

Imas Noviyana

2017-06-01

Full Text Available Top-contact bottom-gate thin film transistors (TFTs with zinc-rich indium zinc tin oxide (IZTO active layer were prepared at room temperature by radio frequency magnetron sputtering. Sintered ceramic target was prepared and used for deposition from oxide powder mixture having the molar ratio of In2O3:ZnO:SnO2 = 2:5:1. Annealing treatment was carried out for as-deposited films at various temperatures to investigate its effect on TFT performances. It was found that annealing treatment at 350 °C for 30 min in air atmosphere yielded the best result, with the high field effect mobility value of 34 cm2/Vs and the minimum subthreshold swing value of 0.12 V/dec. All IZTO thin films were amorphous, even after annealing treatment of up to 350 °C.

High-performance III-V MOSFET with nano-stacked high-k gate dielectric and 3D fin-shaped structure.

Science.gov (United States)

Chen, Szu-Hung; Liao, Wen-Shiang; Yang, Hsin-Chia; Wang, Shea-Jue; Liaw, Yue-Gie; Wang, Hao; Gu, Haoshuang; Wang, Mu-Chun

2012-08-01

A three-dimensional (3D) fin-shaped field-effect transistor structure based on III-V metal-oxide-semiconductor field-effect transistor (MOSFET) fabrication has been demonstrated using a submicron GaAs fin as the high-mobility channel. The fin-shaped channel has a thickness-to-width ratio (TFin/WFin) equal to 1. The nano-stacked high-k Al2O3 dielectric was adopted as a gate insulator in forming a metal-oxide-semiconductor structure to suppress gate leakage. The 3D III-V MOSFET exhibits outstanding gate controllability and shows a high Ion/Ioff ratio > 105 and a low subthreshold swing of 80 mV/decade. Compared to a conventional Schottky gate metal-semiconductor field-effect transistor or planar III-V MOSFETs, the III-V MOSFET in this work exhibits a significant performance improvement and is promising for future development of high-performance n-channel devices based on III-V materials.

Gating techniques for ultrasonic thickness testing using flaw detectors

Energy Technology Data Exchange (ETDEWEB)

Holloway, P., E-mail: paul@hollowayndt.com [Holloway NDT & Engineering Inc., Georgetown, Ontario (Canada)

2016-05-15

The purpose of this article is to provide guidance on settings and methods, in particular the careful use of gating, to ensure accuracy of thickness testing on corroded steel and other metallic components. Specific applications include boiler tubes, tank floors, piping and vessels where the testing is performed from the OD or top surfaces, inspecting for metal loss due to corrosion on the opposite side. (author)

Unified analytical threshold voltage model for non-uniformly doped dual metal gate fully depleted silicon-on-insulator MOSFETs

Science.gov (United States)

Rao, Rathnamala; Katti, Guruprasad; Havaldar, Dnyanesh S.; DasGupta, Nandita; DasGupta, Amitava

2009-03-01

The paper describes the unified analytical threshold voltage model for non-uniformly doped, dual metal gate (DMG) fully depleted silicon-on-insulator (FDSOI) MOSFETs based on the solution of 2D Poisson's equation. 2D Poisson's equation is solved analytically for appropriate boundary conditions using separation of variables technique. The solution is then extended to obtain the threshold voltage of the FDSOI MOSFET. The model is able to handle any kind of non-uniform doping, viz. vertical, lateral as well as laterally asymetric channel (LAC) profile in the SOI film in addition to the DMG structure. The analytical results are validated with the numerical simulations using the device simulator MEDICI.

Piezo-phototronic Boolean logic and computation using photon and strain dual-gated nanowire transistors.

Science.gov (United States)

Yu, Ruomeng; Wu, Wenzhuo; Pan, Caofeng; Wang, Zhaona; Ding, Yong; Wang, Zhong Lin

2015-02-04

Using polarization charges created at the metal-cadmium sulfide interface under strain to gate/modulate electrical transport and optoelectronic processes of charge carriers, the piezo-phototronic effect is applied to process mechanical and optical stimuli into electronic controlling signals. The cascade nanowire networks are demonstrated for achieving logic gates, binary computations, and gated D latches to store information carried by these stimuli. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electronic structure of hcp transition metals

DEFF Research Database (Denmark)

Jepsen, O.; Andersen, O. Krogh; Mackintosh, A. R.

1975-01-01

Using the linear muffin-tin-orbital method described in the previous paper, we have calculated the electronic structures of the hcp transition metals, Zr, Hf, Ru, and Os. We show how the band structures of these metals may be synthesized from the sp and d bands, and illustrate the effects...... of hybridization, relativistic band shifts, and spin-orbit coupling by the example of Os. By making use of parameters derived from the muffin-tin potential, we discuss trends in the positions and widths of the energy bands, especially the d bands, as a function of the location in the periodic table. The densities...... of states of the four metals are presented, and the calculated heat capacities compared with experiment. The Fermi surfaces of both Ru and Os are found to be in excellent quantitative agreement with de Haas-van Alphen measurements, indicating that the calculated d-band position is misplaced by less than 10...

Investigation of TiN thin film oxidation depending on the substrate temperature at vacuum break

Energy Technology Data Exchange (ETDEWEB)

Piallat, Fabien, E-mail: fabien.piallat@gmail.com [STMicroelectronics, 850 rue Jean Monnet, 38920 Crolles (France); CEA, LETI, Campus Minatec, F-38054 Grenoble (France); LTM-CNRS, 17 rue des Martyrs, 38054 Grenoble (France); Gassilloud, Remy [CEA, LETI, Campus Minatec, F-38054 Grenoble (France); Caubet, Pierre [STMicroelectronics, 850 rue Jean Monnet, 38920 Crolles (France); Vallée, Christophe [LTM-CNRS, 17 rue des Martyrs, 38054 Grenoble (France)

2016-09-15

Due to the reduction of the thickness of the layers used in the advanced technology nodes, there is a growing importance of the surface phenomena in the definition of the general properties of the materials. One of the least controlled and understood phenomenon is the oxidation of metals after deposition, at the vacuum break. In this study, the influence of the sample temperature at vacuum break on the oxidation level of TiN deposited by metalorganic chemical vapor deposition is investigated. TiN resistivity appears to be lower for samples which underwent vacuum break at high temperature. Using X-ray photoelectron spectrometry analysis, this change is correlated to the higher oxidation of the TiN layer. Moreover, angle resolved XPS analysis reveals that higher is the temperature at the vacuum break, higher is the surface oxidation of the sample. This surface oxidation is in turn limiting the diffusion of oxygen in the volume of the layer. Additionally, evolution of TiN layers resistivity was monitored in time and it shows that resistivity increases until a plateau is reached after about 10 days, with the lowest temperature at vacuum break resulting in the highest increase, i.e., the resistivity of the sample released to atmosphere at high temperature increased by a factor 1.7 whereas the resistivity of the sample cooled down under vacuum temperature increased by a factor 2.7.

Gas Sensors Based on Tin Oxide Nanoparticles Synthesized from a Mini-Arc Plasma Source

Directory of Open Access Journals (Sweden)

Ganhua Lu

2006-01-01

Full Text Available Miniaturized gas sensors or electronic noses to rapidly detect and differentiate trace amount of chemical agents are extremely attractive. In this paper, we report on the fabrication and characterization of a functional tin oxide nanoparticle gas sensor. Tin oxide nanoparticles are first synthesized using a convenient and low-cost mini-arc plasma source. The nanoparticle size distribution is measured online using a scanning electrical mobility spectrometer (SEMS. The product nanoparticles are analyzed ex-situ by high resolution transmission electron microscopy (HRTEM for morphology and defects, energy dispersive X-ray (EDX spectroscopy for elemental composition, electron diffraction for crystal structure, and X-ray photoelectron spectroscopy (XPS for surface composition. Nonagglomerated rutile tin oxide (SnO2 nanoparticles as small as a few nm have been produced. Larger particles bear a core-shell structure with a metallic core and an oxide shell. The nanoparticles are then assembled onto an e-beam lithographically patterned interdigitated electrode using electrostatic force to fabricate the gas sensor. The nanoparticle sensor exhibits a fast response and a good sensitivity when exposed to 100 ppm ethanol vapor in air.

Comprehensive study and design of scaled metal/high-k/Ge gate stacks with ultrathin aluminum oxide interlayers

Energy Technology Data Exchange (ETDEWEB)

Asahara, Ryohei; Hideshima, Iori; Oka, Hiroshi; Minoura, Yuya; Hosoi, Takuji, E-mail: hosoi@mls.eng.osaka-u.ac.jp; Shimura, Takayoshi; Watanabe, Heiji [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ogawa, Shingo [Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Toray Research Center Inc., 3-3-7 Sonoyama, Otsu, Shiga 520-8567 (Japan); Yoshigoe, Akitaka; Teraoka, Yuden [Japan Atomic Energy Agency, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)

2015-06-08

Advanced metal/high-k/Ge gate stacks with a sub-nm equivalent oxide thickness (EOT) and improved interface properties were demonstrated by controlling interface reactions using ultrathin aluminum oxide (AlO{sub x}) interlayers. A step-by-step in situ procedure by deposition of AlO{sub x} and hafnium oxide (HfO{sub x}) layers on Ge and subsequent plasma oxidation was conducted to fabricate Pt/HfO{sub 2}/AlO{sub x}/GeO{sub x}/Ge stacked structures. Comprehensive study by means of physical and electrical characterizations revealed distinct impacts of AlO{sub x} interlayers, plasma oxidation, and metal electrodes serving as capping layers on EOT scaling, improved interface quality, and thermal stability of the stacks. Aggressive EOT scaling down to 0.56 nm and very low interface state density of 2.4 × 10{sup 11 }cm{sup −2}eV{sup −1} with a sub-nm EOT and sufficient thermal stability were achieved by systematic process optimization.

Removal of heavy metals from metal-containing effluent by yeast ...

African Journals Online (AJOL)

Administrator

2011-09-21

Sep 21, 2011 ... from the chrome and tin effluents of a local iron and steel industry. Key words: ... source of biomass for bioremediation of waste water. It ... microbes. Unz and Shuttleworth (1996) stated that the capacity of biomass to recover metals from waste water depends on its physical, chemical and biological pro-.

XRF measurements of tin, copper and zinc in antifouling paints coated on leisure boats

International Nuclear Information System (INIS)

Ytreberg, Erik; Bighiu, Maria Alexandra; Lundgren, Lennart; Eklund, Britta

2016-01-01

Tributyltin (TBT) and other organotin compounds have been restricted for use on leisure boats since 1989 in the EU. Nonetheless, release of TBT is observed from leisure boats during hull maintenance work, such as pressure hosing. In this work, we used a handheld X-ray Fluorescence analyser (XRF) calibrated for antifouling paint matrixes to measure tin, copper and zinc in antifouling paints coated on leisure boats in Sweden. Our results show that over 10% of the leisure boats (n = 686) contain >400 μg/cm 2 of tin in their antifouling coatings. For comparison, one layer (40 μm dry film) of a TBT-paint equals ≈ 800 μg Sn/cm 2 . To our knowledge, tin has never been used in other forms than organotin (OT) in antifouling paints. Thus, even though the XRF analysis does not provide any information on the speciation of tin, the high concentrations indicate that these leisure boats still have OT coatings present on their hull. On several leisure boats we performed additional XRF measurements by progressively scraping off the top coatings and analysing each underlying layer. The XRF data show that when tin is detected, it is most likely present in coatings close to the hull with several layers of other coatings on top. Thus, leaching of OT compounds from the hull into the water is presumed to be negligible. The risk for environmental impacts arises during maintenance work such as scraping, blasting and high pressure hosing activities. The data also show that many boat owners apply excessive paint layers when following paint manufacturers recommendations. Moreover, high loads of copper were detected even on boats sailing in freshwater, despite the more than 20 year old ban, which poses an environmental risk that has not been addressed until now. - Highlights: • A new XRF application for analysing metals in antifouling paints has been used. • Almost 700 leisure boats were analysed for tin, copper and zinc. • Over 10% of the leisure boats contained high, >400�

Electrodeposition of rhenium-tin nanowires

International Nuclear Information System (INIS)

Naor-Pomerantz, Adi; Eliaz, Noam; Gileadi, Eliezer

2011-01-01

Highlights: → Rhenium-tin nanowires were formed electrochemically, without using a template. → The nanowires consisted of a crystalline-Sn-core/amorphous-Re-shell structure. → The effects of bath composition and operating conditions were investigated. → A mechanism is suggested for the formation of the core/shell structure. → The nanowires may be attractive for a variety of applications. - Abstract: Rhenium (Re) is a refractory metal which exhibits an extraordinary combination of properties. Thus, nanowires and other nanostructures of Re-alloys may possess unique properties resulting from both Re chemistry and the nanometer scale, and become attractive for a variety of applications, such as in catalysis, photovoltaic cells, and microelectronics. Rhenium-tin coatings, consisting of nanowires with a core/shell structure, were electrodeposited on copper substrates under galvanostatic or potentiostatic conditions. The effects of bath composition and operating conditions were investigated, and the chemistry and structure of the coatings were studied by a variety of analytical tools. A Re-content as high as 77 at.% or a Faradaic efficiency as high as 46% were attained. Ranges of Sn-to-Re in the plating bath, applied current density and applied potential, within which the nanowires could be formed, were determined. A mechanism was suggested, according to which Sn nanowires were first grown on top of Sn micro-particles, and then the Sn nanowires reduced the perrhenate chemically, thus forming a core made of crystalline Sn-rich phase, and a shell made of amorphous Re-rich phase. The absence of mutual solubility of Re and Sn may be the driving force for this phase separation.

A gate enhanced power U-shaped MOSFET integrated with a Schottky rectifier

International Nuclear Information System (INIS)

Wang Ying; Jiao Wen-Li; Hu Hai-Fan; Liu Yun-Tao; Cao Fei

2012-01-01

An accumulation gate enhanced power U-shaped metal-oxide-semiconductor field-effect-transistor (UMOSFET) integrated with a Schottky rectifier is proposed. In this device, a Schottky rectifier is integrated into each cell of the accumulation gate enhanced power UMOSFET. Specific on-resistances of 7.7 mΩ·mm 2 and 6.5 mΩ·mm 2 for the gate bias voltages of 5 V and 10 V are achieved, respectively, and the breakdown voltage is 61 V. The numerical simulation shows a 25% reduction in the reverse recovery time and about three orders of magnitude reduction in the leakage current as compared with the accumulation gate enhanced power UMOSFET. (condensed matter: structural, mechanical, and thermal properties)

Mitigating tin whisker risks theory and practice

CERN Document Server

Handwerker, Carol A; Bath, Jasbir

2016-01-01

Discusses the growth mechanisms of tin whiskers and the effective mitigation strategies necessary to reduce whisker growth risks. This book covers key tin whisker topics, ranging from fundamental science to practical mitigation strategies. The text begins with a review of the characteristic properties of local microstructures around whisker and hillock grains to identify why these particular grains and locations become predisposed to forming whiskers and hillocks. The book discusses the basic properties of tin-based alloy finishes and the effects of various alloying elements on whisker formation, with a focus on potential mechanisms for whisker suppression or enhancement for each element. Tin whisker risk mitigation strategies for each tier of the supply chain for high reliability electronic systems are also described.

Touch sensors based on planar liquid crystal-gated-organic field-effect transistors

International Nuclear Information System (INIS)

Seo, Jooyeok; Lee, Chulyeon; Han, Hyemi; Lee, Sooyong; Nam, Sungho; Kim, Youngkyoo; Kim, Hwajeong; Lee, Joon-Hyung; Park, Soo-Young; Kang, Inn-Kyu

2014-01-01

We report a tactile touch sensor based on a planar liquid crystal-gated-organic field-effect transistor (LC-g-OFET) structure. The LC-g-OFET touch sensors were fabricated by forming the 10 μm thick LC layer (4-cyano-4 ′ -pentylbiphenyl - 5CB) on top of the 50 nm thick channel layer (poly(3-hexylthiophene) - P3HT) that is coated on the in-plane aligned drain/source/gate electrodes (indium-tin oxide - ITO). As an external physical stimulation to examine the tactile touch performance, a weak nitrogen flow (83.3 μl/s) was employed to stimulate the LC layer of the touch device. The LC-g-OFET device exhibited p-type transistor characteristics with a hole mobility of 1.5 cm 2 /Vs, but no sensing current by the nitrogen flow touch was measured at sufficiently high drain (V D ) and gate (V G ) voltages. However, a clear sensing current signal was detected at lower voltages, which was quite sensitive to the combination of V D and V G . The best voltage combination was V D = −0.2 V and V G = −1 V for the highest ratio of signal currents to base currents (i.e., signal-to-noise ratio). The change in the LC alignment upon the nitrogen flow touch was assigned as the mechanism for the present LC-g-OFET touch sensors

Bio Organic-Semiconductor Field-Effect Transistor (BioFET) Based on Deoxyribonucleic Acid (DNA) Gate Dielectric

Science.gov (United States)

2010-03-31

floating gate devices and metal-insulator-oxide-semiconductor (MIOS) devices. First attempts to use polarizable gate insulators in combination with...bulk of the semiconductor (ii) Due to the polarizable gate dielectric (iii) dipole polarization and (iv)electret effect due to mobile ions in the...characterization was carried out under an argon environment inside the glove box. An Agilent model E5273A with a two source-measurement unit instrument was

Polycrystalline diamond RF MOSFET with MoO3 gate dielectric

Directory of Open Access Journals (Sweden)

Zeyang Ren

2017-12-01

Full Text Available We report the radio frequency characteristics of the diamond metal-oxide-semiconductor field effect transistor with MoO3 gate dielectric for the first time. The device with 2-μm gate length was fabricated on high quality polycrystalline diamond. The maximum drain current of 150 mA/mm at VGS = -5 V and the maximum transconductance of 27 mS/mm were achieved. The extrinsic cutoff frequency of 1.2 GHz and the maximum oscillation frequency of 1.9 GHz have been measured. The moderate frequency characteristics are attributed to the moderate transconductance limited by the series resistance along the channel. We expect that the frequency characteristics of the device can be improved by increasing the magnitude of gm, or fundamentally decreasing the gate-controlled channel resistance and series resistance along the channel, and down-scaling the gate length.

Study on effective MOSFET channel length extracted from gate capacitance

Science.gov (United States)

Tsuji, Katsuhiro; Terada, Kazuo; Fujisaka, Hisato

2018-01-01

The effective channel length (L GCM) of metal-oxide-semiconductor field-effect transistors (MOSFETs) is extracted from the gate capacitances of actual-size MOSFETs, which are measured by charge-injection-induced-error-free charge-based capacitance measurement (CIEF CBCM). To accurately evaluate the capacitances between the gate and the channel of test MOSFETs, the parasitic capacitances are removed by using test MOSFETs having various channel sizes and a source/drain reference device. A strong linear relationship between the gate-channel capacitance and the design channel length is obtained, from which L GCM is extracted. It is found that L GCM is slightly less than the effective channel length (L CRM) extracted from the measured MOSFET drain current. The reason for this is discussed, and it is found that the capacitance between the gate electrode and the source and drain regions affects this extraction.

Synthesis and characterization of tin and antimony based composites derived by mechanochemical in situ reduction of oxides

International Nuclear Information System (INIS)

Patel, P.; Roy, S.; Kim, I.L.-Seok; Kumta, P.N.

2004-01-01

Composites consisting of tin and silicon dioxide or antimony and silicon dioxide were synthesized using high energy mechanical milling. The composites were made by the reactive milling of SnO or Sb 2 O 3 with pure Si, resulting in the oxidation of silicon and the reduction of the metal oxides. The minimum time required to complete the reaction for the tin system was 170 min, while the minimum time for the antimony system was 230 min. X-ray diffraction and infrared spectroscopy were used to determine the phases present in the composites. In addition, scanning electron microscopy, along with energy dispersive X-ray analysis (EDX), was used to characterize the microstructure and composition of the resultant material

Study of tin amalgam mirrors by {sup 119}Sn Mössbauer spectroscopy and other analytical methods

Energy Technology Data Exchange (ETDEWEB)

Lerf, A. [Bavarian Academy of Sciences, Walther Meißner Institute (Germany); Wagner, F. E., E-mail: fwagner@tum.de [Technical University of Munich, Physics Department E15 (Germany); Herrera, L. K. [Universidad Nacional de Colombia. Dpto. de Ingeniería Mecánica y Mecatrónica (Colombia); Justo, A.; Mu noz-Páez, A.; Pérez-Rodríguez, J. L. [University of Sevilla-CSIC, ICMSE (Spain)

2016-12-15

From the beginning of the 16 {sup th} until the end of the 19 {sup th} century the most widely used mirrors consisted of a pane of glass backed with a reflecting layer of tin-mercury amalgam. They were made by sliding the glass pane over a tin foil covered with liquid mercury. After removal of the superfluous mercury, tin amalgam formed slowly at ambient temperature and yielded a reflecting layer adhering to the surface of the glass. Such mirrors often deteriorate in the course of time by oxidation of the tin in the amalgam to stannous or stannic oxide. {sup 119}Sn Mössbauer spectroscopy, scanning electron microscopy, micro-XRF and X-ray diffraction have been used to study this deterioration process. The studied specimens were a modern mirror made for the reconstruction of the Green Vault in Dresden in the early 2000s, two rather well preserved German mirrors from the 17 {sup th} and 19 {sup th} centuries and several strongly deteriorated specimens of Baroque mirrors from the south of Spain. The modern mirror consists mainly of a Sn{sub 0.9}Hg{sub 0.1} amalgam with only 2 % of SnO{sub 2}. The older German mirrors showed more pronounced oxidation, containing 12 and 15 % of SnO{sub 2}, which did not noticeably impair their reflectivity. In the samples from the Spanish mirrors at best a few percent of metallic phase was left. The majority of the tin had oxidised to SnO{sub 2}, but between 8 and 20 % of the tin was present as SnO. X-ray diffraction yielded similar results and micro-XRF mapping using synchrotron radiation for excitation gave information on the distribution of Sn and Hg in the reflecting layer of the mirrors.

Metal Hydride assited contamination on Ru/Si surfaces

NARCIS (Netherlands)

Pachecka, Malgorzata; Lee, Christopher James; Sturm, Jacobus Marinus; Bijkerk, Frederik

2013-01-01

In extreme ultraviolet lithography (EUVL) residual tin, in the form of particles, ions, and atoms, can be deposited on nearby EUV optics. During the EUV pulse, a reactive hydrogen plasma is formed, which may be able to react with metal contaminants, creating volatile and unstable metal hydrides that

Interfacial delamination in polymer coated metal sheet : a numerical-experimental study

NARCIS (Netherlands)

van den Bosch, M.

2007-01-01

An increasing amount of products are nowadays made of polymer coated metal sheet. Polymer coated metal has several advantages compared to traditionally Sn (tin) coated metal, such as costs savings and a more environmental friendly production process. Beverage and food cans are formed by draw-redraw

Quantum ballistic analysis of transition metal dichalcogenides based double gate junctionless field effect transistor and its application in nano-biosensor

Science.gov (United States)

Shadman, Abir; Rahman, Ehsanur; Khosru, Quazi D. M.

2017-11-01

To reduce the thermal budget and the short channel effects in state of the art CMOS technology, Junctionless field effect transistor (JLFET) has been proposed in the literature. Numerous experimental, modeling, and simulation based works have been done on this new FET with bulk materials for various geometries until now. On the other hand, the two-dimensional layered material is considered as an alternative to current Si technology because of its ultra-thin body and high mobility. Very recently few simulation based works have been done on monolayer molybdenum disulfide based JLFET mainly to show the advantage of JLFET over conventional FET. However, no comprehensive simulation-based work has been done for double gate JLFET keeping in mind the prominent transition metal dichalcogenides (TMDC) to the authors' best knowledge. In this work, we have studied quantum ballistic drain current-gate voltage characteristics of such FETs within non-equilibrium Green's function (NEGF) framework. Our simulation results reveal that all these TMDC materials are viable options for implementing state of the art Junctionless MOSFET with emphasis on their performance at short gate lengths. Besides evaluating the prospect of TMDC materials in the digital logic application, the performance of Junctionless Double Gate trilayer TMDC heterostructure FET for the label-free electrical detection of biomolecules in dry environment has been investigated for the first time to the authors' best knowledge. The impact of charge neutral biomolecules on the electrical characteristics of the biosensor has been analyzed under dry environment situation. Our study shows that these materials could provide high sensitivity in the sub-threshold region as a channel material in nano-biosensor, a trend demonstrated by silicon on insulator FET sensor in the literature. Thus, going by the trend of replacing silicon with these novel materials in device level, TMDC heterostructure could be a viable alternative to

Effect of Graphene Addition on Mechanical Properties of TiN

International Nuclear Information System (INIS)

Shon, In-Jin; Yoon, Jin-Kook; Hong, Kyung-Tae

2017-01-01

Despite of many attractive properties of TiN, the current concern about the TiN focuses on its low fracture toughness below the ductile-brittle transition temperature. To improve its mechanical properties, the approach generally utilized has been the addition of a second phase to form composites and to make nanostructured materials. In this respect, highly dense nanostructured TiN and TiN-graphene composites were obtained within two min at 1250 ℃. The grain size of TiN was reduced remarkably by the addition of graphene. The addition of graphene to TiN simultaneously improved the fracture toughness and hardness of TiN-graphene composite due to refinement of TiN and deterring crack propagation by graphene. This study demonstrates that the graphene can be an effective reinforcing agent for improved hardness and fracture toughness of TiN composites.

Effect of Graphene Addition on Mechanical Properties of TiN

Energy Technology Data Exchange (ETDEWEB)

Shon, In-Jin [Chonbuk National University, Jeonju (Korea, Republic of); Yoon, Jin-Kook; Hong, Kyung-Tae [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

2017-03-15

Despite of many attractive properties of TiN, the current concern about the TiN focuses on its low fracture toughness below the ductile-brittle transition temperature. To improve its mechanical properties, the approach generally utilized has been the addition of a second phase to form composites and to make nanostructured materials. In this respect, highly dense nanostructured TiN and TiN-graphene composites were obtained within two min at 1250 ℃. The grain size of TiN was reduced remarkably by the addition of graphene. The addition of graphene to TiN simultaneously improved the fracture toughness and hardness of TiN-graphene composite due to refinement of TiN and deterring crack propagation by graphene. This study demonstrates that the graphene can be an effective reinforcing agent for improved hardness and fracture toughness of TiN composites.

Metal-insulator transition in tin doped indium oxide (ITO thin films: Quantum correction to the electrical conductivity

Directory of Open Access Journals (Sweden)

Deepak Kumar Kaushik

2017-01-01

Full Text Available Tin doped indium oxide (ITO thin films are being used extensively as transparent conductors in several applications. In the present communication, we report the electrical transport in DC magnetron sputtered ITO thin films (prepared at 300 K and subsequently annealed at 673 K in vacuum for 60 minutes in low temperatures (25-300 K. The low temperature Hall effect and resistivity measurements reveal that the ITO thin films are moderately dis-ordered (kFl∼1; kF is the Fermi wave vector and l is the electron mean free path and degenerate semiconductors. The transport of charge carriers (electrons in these disordered ITO thin films takes place via the de-localized states. The disorder effects lead to the well-known ‘metal-insulator transition’ (MIT which is observed at 110 K in these ITO thin films. The MIT in ITO thin films is explained by the quantum correction to the conductivity (QCC; this approach is based on the inclusion of quantum-mechanical interference effects in Boltzmann’s expression of the conductivity of the disordered systems. The insulating behaviour observed in ITO thin films below the MIT temperature is attributed to the combined effect of the weak localization and the electron-electron interactions.

Metal-insulator transition in tin doped indium oxide (ITO) thin films: Quantum correction to the electrical conductivity

Science.gov (United States)

Kaushik, Deepak Kumar; Kumar, K. Uday; Subrahmanyam, A.

2017-01-01

Tin doped indium oxide (ITO) thin films are being used extensively as transparent conductors in several applications. In the present communication, we report the electrical transport in DC magnetron sputtered ITO thin films (prepared at 300 K and subsequently annealed at 673 K in vacuum for 60 minutes) in low temperatures (25-300 K). The low temperature Hall effect and resistivity measurements reveal that the ITO thin films are moderately dis-ordered (kFl˜1; kF is the Fermi wave vector and l is the electron mean free path) and degenerate semiconductors. The transport of charge carriers (electrons) in these disordered ITO thin films takes place via the de-localized states. The disorder effects lead to the well-known `metal-insulator transition' (MIT) which is observed at 110 K in these ITO thin films. The MIT in ITO thin films is explained by the quantum correction to the conductivity (QCC); this approach is based on the inclusion of quantum-mechanical interference effects in Boltzmann's expression of the conductivity of the disordered systems. The insulating behaviour observed in ITO thin films below the MIT temperature is attributed to the combined effect of the weak localization and the electron-electron interactions.

Microwave plasma CVD of NANO structured tin/carbon composites

Science.gov (United States)

Marcinek, Marek [Warszawa, PL; Kostecki, Robert [Lafayette, CA

2012-07-17

A method for forming a graphitic tin-carbon composite at low temperatures is described. The method involves using microwave radiation to produce a neutral gas plasma in a reactor cell. At least one organo tin precursor material in the reactor cell forms a tin-carbon film on a supporting substrate disposed in the cell under influence of the plasma. The three dimensional carbon matrix material with embedded tin nanoparticles can be used as an electrode in lithium-ion batteries.

Transparent indium-tin oxide/indium-gallium-zinc oxide Schottky diodes formed by gradient oxygen doping

Science.gov (United States)

Ho, Szuheng; Yu, Hyeonggeun; So, Franky

2017-11-01

Amorphous InGaZnO (a-IGZO) is promising for transparent electronics due to its high carrier mobility and optical transparency. However, most metal/a-IGZO junctions are ohmic due to the Fermi-level pinning at the interface, restricting their device applications. Here, we report that indium-tin oxide/a-IGZO Schottky diodes can be formed by gradient oxygen doping in the a-IGZO layer that would otherwise form an ohmic contact. Making use of back-to-back a-IGZO Schottky junctions, a transparent IGZO permeable metal-base transistor is also demonstrated with a high common-base gain.

Temperature measurement of tin under shock compression

International Nuclear Information System (INIS)

Hereil, Pierre-Louis; Mabire, Catherine

2002-01-01

The results of pyrometric measurements performed at the interface of a tin target with a LiF window material are presented for stresses ranging from 38 to 55 GPa. The purpose of the study is to analyze the part of the interface in the temperature measurement by a multi-channel pyrometric device. The results show that the glue used at target/window interface remains transparent under shock. The values of temperature measured at the tin/LiF interface are consistent with the behavior of tin under shock

Electron transport in a double quantum ring: Evidence of an AND gate

International Nuclear Information System (INIS)

Maiti, Santanu K.

2009-01-01

We explore AND gate response in a double quantum ring where each ring is threaded by a magnetic flux φ. The double quantum ring is attached symmetrically to two semi-infinite one-dimensional metallic electrodes and two gate voltages, namely, V a and V b , are applied, respectively, in the lower arms of the two rings which are treated as two inputs of the AND gate. The system is described in the tight-binding framework and the calculations are done using the Green's function formalism. Here we numerically compute the conductance-energy and current-voltage characteristics as functions of the ring-to-electrode coupling strengths, magnetic flux and gate voltages. Our study suggests that, for a typical value of the magnetic flux φ=φ 0 /2 (φ 0 =ch/e, the elementary flux-quantum) a high output current (1) (in the logical sense) appears only if both the two inputs to the gate are high (1), while if neither or only one input to the gate is high (1), a low output current (0) results. It clearly demonstrates the AND gate behavior and this aspect may be utilized in designing an electronic logic gate.

Metal alkoxides as starting materials for hydrolysis processes

International Nuclear Information System (INIS)

Mukhtar, Omaima Awad

1999-12-01

In this thesis the preparation of some metal alkoxides and their hydrolysis products were studied. The characteristic of each prepared alkoxides and their hydrolyzates were determined. Tetra ethoxysilane was prepared by the elemental route (the reaction of silicon powder with liquid ethanol) in the presence of tin ethoxide as a catalyst. The use of tin alkoxide is considered one of the most developed ways used recently in chemistry, compared to the usage of acids and bases as catalyst previously. It had been confirmed by the usage of (infrared) IR spectroscopy, the structure of the prepared material. Also tin isopropoxide had been prepared and hydrolyzed. Ethoxides of aluminium, magnesium and tin had been prepared by the elemental route. The gelation product had been analyzed. tetraethoxysilane had been also prepared by the halosilane route. Isopropoxide of each aluminium, magnesium and tin had been synthesized, hydrolyzed, allowed to gel and analyzed by IR (infrared) spectroscopy and gas-liquid chromatography. However, results obtained indicated that tin ethoxide is an effective catalyst in the direct synthesis of tetraethoxysilane from silicon powder and liquid ethanol. Gas-liquid chromatography, infra-red (IR) analysis showed that the final reaction product was tetraethoxysilane. (Author)

Synthesis and characterization of tin(II) complexes of fluorinated Schiff bases derived from amino acids.

Science.gov (United States)

Singh, Har Lal

2010-07-01

New tin(II) complexes of general formula Sn(L)(2) (L=monoanion of 3-methyl-4-fluoro-acetophenone phenylalanine L(1)H, 3-methyl-4-fluoro-acetophenone alanine L(2)H, 3-methyl-4-fluoro acetophenone tryptophan L(3)H, 3-methyl-4-fluoro-acetophenone valine L(4)H, 3-methyl-4-fluoro-acetophenone isoleucine L(5)H and 3-methyl-4-fluoro-acetophenone glycine L(6)H) have been prepared. It is characterized by elemental analyses, molar conductance measurements and molecular weight determinations. Bonding of these complexes is discussed in terms of their UV-visible, infrared, and nuclear magnetic resonance ((1)H, (13)C, (19)F and (119)Sn NMR) spectral studies. The ligands act as bidentate towards metal ions, via the azomethine nitrogen and deprotonated oxygen of the respective amino acid. Elemental analyses and NMR spectral data of the ligands with their tin(II) complexes agree with their proposed square pyramidal structures. A few representative ligands and their tin complexes have been screened for their antibacterial activities and found to be quite active in this respect. Copyright 2010 Elsevier B.V. All rights reserved.

Transparent electrode designs based on optimal nano-patterning of metallic films

KAUST Repository

Catrysse, Peter B.; Fan, Shanhui

2010-01-01

, such as indium tin oxide, are commonly used. There is substantial interest in replacing them, however, motivated by practical problems and recent discoveries regarding the optics of nano-patterned metals. When designing nano-patterned metallic films for use

Molecular-beam-deposited yttrium-oxide dielectrics in aluminum-gated metal - oxide - semiconductor field-effect transistors: Effective electron mobility

International Nuclear Information System (INIS)

Ragnarsson, L.-A degree.; Guha, S.; Copel, M.; Cartier, E.; Bojarczuk, N. A.; Karasinski, J.

2001-01-01

We report on high effective mobilities in yttrium-oxide-based n-channel metal - oxide - semiconductor field-effect transistors (MOSFETs) with aluminum gates. The yttrium oxide was grown in ultrahigh vacuum using a reactive atomic-beam-deposition system. Medium-energy ion-scattering studies indicate an oxide with an approximate composition of Y 2 O 3 on top of a thin layer of interfacial SiO 2 . The thickness of this interfacial oxide as well as the effective mobility are found to be dependent on the postgrowth anneal conditions. Optimum conditions result in mobilities approaching that of SiO 2 -based MOSFETs at higher fields with peak mobilities at approximately 210 cm 2 /Vs. [copyright] 2001 American Institute of Physics

Intrinsic multistate switching of gold clusters through electrochemical gating

DEFF Research Database (Denmark)

Albrecht, Tim; Mertens, S.F.L.; Ulstrup, Jens

2007-01-01

The electrochemical behavior of small metal nanoparticles is governed by Coulomb-like charging and equally spaced charge-transfer transitions. Using electrochemical gating at constant bias voltage, we show, for the first time, that individual nanoparticles can be operated as multistate switches i...

Direct protein detection with a nano-interdigitated array gate MOSFET.

Science.gov (United States)

Tang, Xiaohui; Jonas, Alain M; Nysten, Bernard; Demoustier-Champagne, Sophie; Blondeau, Franoise; Prévot, Pierre-Paul; Pampin, Rémi; Godfroid, Edmond; Iñiguez, Benjamin; Colinge, Jean-Pierre; Raskin, Jean-Pierre; Flandre, Denis; Bayot, Vincent

2009-08-15

A new protein sensor is demonstrated by replacing the gate of a metal oxide semiconductor field effect transistor (MOSFET) with a nano-interdigitated array (nIDA). The sensor is able to detect the binding reaction of a typical antibody Ixodes ricinus immunosuppressor (anti-Iris) protein at a concentration lower than 1 ng/ml. The sensor exhibits a high selectivity and reproducible specific detection. We provide a simple model that describes the behavior of the sensor and explains the origin of its high sensitivity. The simulated and experimental results indicate that the drain current of nIDA-gate MOSFET sensor is significantly increased with the successive binding of the thiol layer, Iris and anti-Iris protein layers. It is found that the sensor detection limit can be improved by well optimizing the geometrical parameters of nIDA-gate MOSFET. This nanobiosensor, with real-time and label-free capabilities, can easily be used for the detection of other proteins, DNA, virus and cancer markers. Moreover, an on-chip associated electronics nearby the sensor can be integrated since its fabrication is compatible with complementary metal oxide semiconductor (CMOS) technology.

Telomere dysfunction and cell survival: roles for distinctTIN2-containing complexes

Energy Technology Data Exchange (ETDEWEB)

Kim, Sahn-Ho; Davalos, Albert R.; Heo, Seok-Jin; Rodier, Francis; Beausejour, Christian; Kaminker, Patrick; Campisi, Judith

2006-11-07

Telomeres are maintained by three DNA binding proteins, TRF1, TRF2 and POT1, and several associated factors. One factor, TIN2, binds TRF1 and TRF2 directly and POT1 indirectly. These and two other proteins form a soluble complex that may be the core telomere-maintenance complex. It is not clear whether subcomplexes exist or function in vivo. Here, we provide evidence for two TIN2 subcomplexes with distinct functions in human cells. TIN2 ablation by RNA interference caused telomere uncapping and p53-independent cell death in all cells tested. However, we isolated two TIN2 complexes from cell lysates, each selectively sensitive to a TIN2 mutant (TIN2-13, TIN2-15C). In cells with wild-type p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere uncapping and eventual growth arrest. In cells lacking p53 function, TIN215C more than TIN2-13 caused genomic instability and cell death. Thus, TIN2 subcomplexes likely have distinct functions in telomere maintenance, and may provide selective targets for eliminating cells with mutant p53.

Vacancy-fluorine complexes and their impact on the properties of metal-oxide transistors with high-k gate dielectrics studied using monoenergetic positron beams

Science.gov (United States)

Uedono, A.; Inumiya, S.; Matsuki, T.; Aoyama, T.; Nara, Y.; Ishibashi, S.; Ohdaira, T.; Suzuki, R.; Miyazaki, S.; Yamada, K.

2007-09-01

Vacancy-fluorine complexes in metal-oxide semiconductors (MOS) with high-k gate dielectrics were studied using a positron annihilation technique. F+ ions were implanted into Si substrates before the deposition of gate dielectrics (HfSiON). The shift of threshold voltage (Vth) in MOS capacitors and an increase in Fermi level position below the HfSiON/Si interface were observed after F+ implantation. Doppler broadening spectra of the annihilation radiation and positron lifetimes were measured before and after HfSiON fabrication processes. From a comparison between Doppler broadening spectra and those obtained by first-principles calculation, the major defect species in Si substrates after annealing treatment (1050 °C, 5 s) was identified as vacancy-fluorine complexes (V3F2). The origin of the Vth shift in the MOS capacitors was attributed to V3F2 located in channel regions.

100-nm gate lithography for double-gate transistors

Science.gov (United States)

Krasnoperova, Azalia A.; Zhang, Ying; Babich, Inna V.; Treichler, John; Yoon, Jung H.; Guarini, Kathryn; Solomon, Paul M.

2001-09-01

The double gate field effect transistor (FET) is an exploratory device that promises certain performance advantages compared to traditional CMOS FETs. It can be scaled down further than the traditional devices because of the greater electrostatic control by the gates on the channel (about twice as short a channel length for the same gate oxide thickness), has steeper sub-threshold slope and about double the current for the same width. This paper presents lithographic results for double gate FET's developed at IBM's T. J. Watson Research Center. The device is built on bonded wafers with top and bottom gates self-aligned to each other. The channel is sandwiched between the top and bottom polysilicon gates and the gate length is defined using DUV lithography. An alternating phase shift mask was used to pattern gates with critical dimensions of 75 nm, 100 nm and 125 nm in photoresist. 50 nm gates in photoresist have also been patterned by 20% over-exposure of nominal 100 nm lines. No trim mask was needed because of a specific way the device was laid out. UV110 photoresist from Shipley on AR-3 antireflective layer were used. Process windows, developed and etched patterns are presented.

Study of tin amalgam mirrors by "1"1"9Sn Mössbauer spectroscopy and other analytical methods

International Nuclear Information System (INIS)

Lerf, A.; Wagner, F. E.; Herrera, L. K.; Justo, A.; Mu noz-Páez, A.; Pérez-Rodríguez, J. L.

2016-01-01

From the beginning of the 16 "t"h until the end of the 19 "t"h century the most widely used mirrors consisted of a pane of glass backed with a reflecting layer of tin-mercury amalgam. They were made by sliding the glass pane over a tin foil covered with liquid mercury. After removal of the superfluous mercury, tin amalgam formed slowly at ambient temperature and yielded a reflecting layer adhering to the surface of the glass. Such mirrors often deteriorate in the course of time by oxidation of the tin in the amalgam to stannous or stannic oxide. "1"1"9Sn Mössbauer spectroscopy, scanning electron microscopy, micro-XRF and X-ray diffraction have been used to study this deterioration process. The studied specimens were a modern mirror made for the reconstruction of the Green Vault in Dresden in the early 2000s, two rather well preserved German mirrors from the 17 "t"h and 19 "t"h centuries and several strongly deteriorated specimens of Baroque mirrors from the south of Spain. The modern mirror consists mainly of a Sn_0_._9Hg_0_._1 amalgam with only 2 % of SnO_2. The older German mirrors showed more pronounced oxidation, containing 12 and 15 % of SnO_2, which did not noticeably impair their reflectivity. In the samples from the Spanish mirrors at best a few percent of metallic phase was left. The majority of the tin had oxidised to SnO_2, but between 8 and 20 % of the tin was present as SnO. X-ray diffraction yielded similar results and micro-XRF mapping using synchrotron radiation for excitation gave information on the distribution of Sn and Hg in the reflecting layer of the mirrors.

Volumetric measurement of human red blood cells by MOSFET-based microfluidic gate.

Science.gov (United States)

Guo, Jinhong; Ai, Ye; Cheng, Yuanbing; Li, Chang Ming; Kang, Yuejun; Wang, Zhiming

2015-08-01

In this paper, we present a MOSFET-based (metal oxide semiconductor field-effect transistor) microfluidic gate to characterize the translocation of red blood cells (RBCs) through a gate. In the microfluidic system, the bias voltage modulated by the particles or biological cells is connected to the gate of MOSFET. The particles or cells can be detected by monitoring the MOSFET drain current instead of DC/AC-gating method across the electronic gate. Polystyrene particles with various standard sizes are utilized to calibrate the proposed device. Furthermore, RBCs from both adults and newborn blood sample are used to characterize the performance of the device in distinguishing the two types of RBCs. As compared to conventional DC/AC current modulation method, the proposed device demonstrates a higher sensitivity and is capable of being a promising platform for bioassay analysis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method and apparatus for dissociating metals from metal compounds extracted into supercritical fluids

Science.gov (United States)

Wai, Chien M.; Hunt, Fred H.; Smart, Neil G.; Lin, Yuehe

2000-01-01

A method for dissociating metal-ligand complexes in a supercritical fluid by treating the metal-ligand complex with heat and/or reducing or oxidizing agents is described. Once the metal-ligand complex is dissociated, the resulting metal and/or metal oxide form fine particles of substantially uniform size. In preferred embodiments, the solvent is supercritical carbon dioxide and the ligand is a .beta.-diketone such as hexafluoroacetylacetone or dibutyldiacetate. In other preferred embodiments, the metals in the metal-ligand complex are copper, silver, gold, tungsten, titanium, tantalum, tin, or mixtures thereof. In preferred embodiments, the reducing agent is hydrogen. The method provides an efficient process for dissociating metal-ligand complexes and produces easily-collected metal particles free from hydrocarbon solvent impurities. The ligand and the supercritical fluid can be regenerated to provide an economic, efficient process.

In-Ga-Zn-oxide thin-film transistors with Sb2TeOx gate insulators fabricated by reactive sputtering using a metallic Sb2Te target

International Nuclear Information System (INIS)

Cheong, Woo-Seok

2011-01-01

Using reactive sputtering, we made transparent amorphous Sb 2 TeO x thin films from a metallic Sb 2 Te target in an oxidizing atmosphere. In-Ga-Zn-oxide thin-film transistors (IGZO TFTs) with Sb 2 TeO x gate insulators deposited at room temperature showed a large hysteresis with a counter clockwise direction, which was caused by mobile charges in the gate insulators. The problems of the mobile charges was solved by using Sb 2 TeO x films formed at 250 .deg. C. After the IGZO TFT had been annealed at 200 .deg. C for 1 hour in an O 2 ambient, the mobility of the IGZO TFT was 22.41 cm 2 /Vs, and the drain current on-off ratio was ∼10 8 .

Metal shell technology based upon hollow jet instability

International Nuclear Information System (INIS)

Kendall, J.M.; Lee, M.C.; Wang, T.G.

1982-01-01

Spherical shells of submillimeter size are sought as ICF targets. Such shells must be dimensionally precise, smooth, of high strength, and composed of a high atomic number material. We describe a technology for the production of shells based upon the hydrodynamic instability of an annular jet of molten metal. We have produced shells in the 0.7--2.0 mm size range using tin as a test material. Specimens exhibit good sphericity, fair concentricity, and excellent finish over most of the surface. Work involving a gold--lead--antimony alloy is in progress. Droplets of this are amorphous and possess superior surface finish. The flow of tin models that of the alloy well; experiments on both metals show that the technique holds considerable promise

Telomere dysfunction and cell survival: Roles for distinct TIN2-containing complexes

Energy Technology Data Exchange (ETDEWEB)

Kim, Sahn-ho; Davalos, Albert R.; Heo, Seok-Jin; Rodier, Francis; Zou, Ying; Beausejour, Christian; Kaminker, Patrick; Yannone, Steven M.; Campisi, Judith

2007-10-02

Telomeres are maintained by three DNA binding proteins (TRF1, TRF2 and POT1), and several associated factors. One factor, TIN2, binds TRF1 and TRF2 directly and POT1 indirectly. Along with two other proteins, TPP1 and hRap1, these form a soluble complex that may be the core telomere maintenance complex. It is not clear whether sub-complexes also exist in vivo. We provide evidence for two TIN2 sub-complexes with distinct functions in human cells. We isolated these two TIN2 sub-complexes from nuclear lysates of unperturbed cells and cells expressing TIN2 mutants TIN2-13, TIN2-15C, which cannot bind TRF2 or TRF1, respectively. In cells with wild-type p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere uncapping and eventual growth arrest. In cells lacking p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere dysfunction and cell death. Our findings suggest that distinct TIN2 complexes exist, and that TIN2-15C-sensitive subcomplexes are particularly important for cell survival in the absence of functional p53.

Gating-ML: XML-based gating descriptions in flow cytometry.

Science.gov (United States)

Spidlen, Josef; Leif, Robert C; Moore, Wayne; Roederer, Mario; Brinkman, Ryan R

2008-12-01

The lack of software interoperability with respect to gating due to lack of a standardized mechanism for data exchange has traditionally been a bottleneck, preventing reproducibility of flow cytometry (FCM) data analysis and the usage of multiple analytical tools. To facilitate interoperability among FCM data analysis tools, members of the International Society for the Advancement of Cytometry (ISAC) Data Standards Task Force (DSTF) have developed an XML-based mechanism to formally describe gates (Gating-ML). Gating-ML, an open specification for encoding gating, data transformations and compensation, has been adopted by the ISAC DSTF as a Candidate Recommendation. Gating-ML can facilitate exchange of gating descriptions the same way that FCS facilitated for exchange of raw FCM data. Its adoption will open new collaborative opportunities as well as possibilities for advanced analyses and methods development. The ISAC DSTF is satisfied that the standard addresses the requirements for a gating exchange standard.

Preliminary study of tin slag concrete mixture

Science.gov (United States)

Hashim, Mohd Jamil; Mansor, Ishak; Pauzi Ismail, Mohamad; Sani, Suhairy; Azmi, Azhar; Sayuti, Shaharudin; Zaidi Ibrahim, Mohd; Adli Anuar, Abul; Rahim, Abdul Adha Abdul

2018-01-01

The study focuses on practices to facilitate tin smelting industry to reduce radioactive waste product (Tin Slag) by diluting its radioactivity to a safe level and turning it to a safer infrastructural building product. In the process the concrete mix which include Portland cement, sand, tin slag, water and plasticizer are used to produce interlocking brick pavements, piles and other infrastructural products. The mixing method follows DOE (UK) standard method of mixing targeted at in selected compressive strength suitable for its function and durability. A batching machine is used in the mixing and six test cubes are produced for the test. The testing equipment used are a compressional machine, ultrasonic measurement and a Geiger Muller counter to evaluate of the concrete mix to find the lowest emission of radiation surface dose without compromising the strength of concrete mix. The result obtained indicated the radioactivity of tin slag in the mixing process has reduced to background level that is 0.5μSv/h while the strength and workability of the concrete has not been severely affected. In conclusion, the concrete mix with tin slag has shown the potential it can be turned into a safe beneficial infrastructural product with good strength.

Evaluation of the Content of Lead, Cadmium, Mercury, Arsenic, Tin, Copper and Zinc during the Production Process Flow of Tomato Broth

Directory of Open Access Journals (Sweden)

Corina Andrei

2013-11-01

Full Text Available Heavy metals are among the largest contaminants of food products. Once metals are present in vegetables, their concentrations are rarely modified by industrial processing techniques, although in some cases washing may decrease the metal content. The main objective of this study was to quantify the effect of industrial processing on the content of lead, cadmium, mercury, arsenic, tin, copper and zinc in tomatoes and products resulting on flow technology of tomato broth. For the determination of essential elements and/or potentially toxic was use atomic absorption spectrometry. The analytical results for quantitative evaluation the concentrations of the investigated elements on the samples of tomatoes taken from the technological process of the production of tomato broth indicated the presence of Pb, Cd, Cu and Zn but with a level of concentration that significantly decreased in the finished product and the absence of metals Hg and As in all investigated samples. Effect of industrial processing on the content of tin in tomato samples analyzed was characterized by fluctuations in the residual content that led to a significant increase in concentration of 0.100 ± 0.041 mg kg-1 (tomatoes - unprocessed to 0.200 ± 0.041 mg kg-1 (tomato broth.

Metallography and microstructure interpretation of some archaeological tin bronze vessels from Iran

Energy Technology Data Exchange (ETDEWEB)

Oudbashi, Omid, E-mail: o.oudbashi@aui.ac.ir [Department of Conservation of Historic Properties, Faculty of Conservation, Art University of Isfahan, Hakim Nezami Street, Sangtarashha Alley, P.O. Box 1744, Isfahan (Iran, Islamic Republic of); Davami, Parviz, E-mail: pdavami@razi-foundation.com [Faculty of Material Science and Engineering, Sharif University of Technology/Razi Applied Science Foundation, No. 27, Fernan St., Shahid Ghasem Asghari Blvd., km 21 of Karadj Makhsous Road, Tehran (Iran, Islamic Republic of)

2014-11-15

Archaeological excavations in western Iran have recently revealed a significant Luristan Bronzes collection from Sangtarashan archaeological site. The site and its bronze collection are dated to Iron Age II/III of western Iran (10th–7th century BC) according to archaeological research. Alloy composition, microstructure and manufacturing technique of some sheet metal vessels are determined to reveal metallurgical processes in western Iran in the first millennium BC. Experimental analyses were carried out using Scanning Electron Microscopy–Energy Dispersive X-ray Spectroscopy and Optical Microscopy/Metallography methods. The results allowed reconstructing the manufacturing process of bronze vessels in Luristan. It proved that the samples have been manufactured with a binary copper–tin alloy with a variable tin content that may relates to the application of an uncontrolled procedure to make bronze alloy (e.g. co-smelting or cementation). The presence of elongated copper sulphide inclusions showed probable use of copper sulphide ores for metal production and smelting. Based on metallographic studies, a cycle of cold working and annealing was used to shape the bronze vessels. - Highlights: • Sangtarashan vessels are made by variable Cu-Sn alloys with some impurities. • Various compositions occurred due to applying uncontrolled smelting methods. • The microstructure represents thermo-mechanical process to shape bronze vessels. • In one case, the annealing didn’t remove the eutectoid remaining from casting. • The characteristics of the bronzes are similar to other Iron Age Luristan Bronzes.

Electrical properties of ZnO-based bottom-gate thin film transistors fabricated by using radio frequency magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Navamathavan, R. [Nano Thin Film Materials Laboratory, Department of Physics, Cheju National University, Jeju 690-756 (Korea, Republic of)], E-mail: n_mathavan@yahoo.com; Choi, Chi Kyu [Nano Thin Film Materials Laboratory, Department of Physics, Cheju National University, Jeju 690-756 (Korea, Republic of); Park, Seong-Ju [Nanophotonic Semiconductors Laboratory, Department of Materials Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

2009-05-05

We report on enhancement-mode thin film transistors (TFTs) using ZnO as an active channel layer deposited by radio frequency (rf) magnetron sputtering at 300 deg. C. The TFT structure consisted of ZnO as a channel, SiN{sub x} as a gate insulator and indium tin oxide (ITO) as a gate which were deposited onto a Corning glass substrate. X-ray diffraction pattern revealed that dense columnar structure of closely packed ZnO nano grains along the c-axis. The transfer characteristics of a typical ZnO TFT exhibited a field effect mobility of 31 cm{sup 2}/V s, a drain current on/off ratio of 10{sup 4}, the low off-current value in the order of 10{sup -10} A, and a threshold voltage of 1.7 V. The transparent ZnO TFT exhibited n-channel enhancement mode behavior.

Radiation-hardened gate-around n-MOSFET structure for radiation-tolerant application-specific integrated circuits

International Nuclear Information System (INIS)

Lee, Min Su; Lee, Hee Chul

2012-01-01

To overcome the total ionizing dose effect on an n-type metal-oxide-semiconductor field-effect transistor (n-MOSFET), we designed a radiation-hardened gate-around n-MOSFET structure and evaluated it through a radiation-exposure experiment. Each test device was fabricated in a commercial 0.35-micron complementary metal-oxide-semiconductor (CMOS) process. The fabricated devices were evaluated under a total dose of 1 Mrad (Si) at a dose rate of 250 krad/h to obtain very high reliability for space electronics. The experimental results showed that the gate-around n-MOSFET structure had very good performance against 1 Mrad (Si) of gamma radiation, while the conventional n-MOSFET experienced a considerable amount of radiation-induced leakage current. Furthermore, a source follower designed with the gate-around transistor worked properly at 1 Mrad (Si) of gamma radiation while a source follower designed with the conventional n-MOSFET lost its functionality.

Negative differential transconductance in electrolyte-gated ruthenate

International Nuclear Information System (INIS)

Hassan, Muhammad Umair; Dhoot, Anoop Singh; Wimbush, Stuart C.

2015-01-01

We report on a study of electric field-induced doping of the highly conductive ruthenate SrRuO 3 using an ionic liquid as the gate dielectric in a field-effect transistor configuration. Two distinct carrier transport regimes are identified for increasing positive gate voltage in thin (10 nm) films grown heteroepitaxially on SrTiO 3 substrates. For V g  = 2 V and lower, the sample shows an increased conductivity of up to 13%, as might be expected for electron doping of a metal. At higher V g  = 2.5 V, we observe a large decrease in electrical conductivity of >20% (at 4.2 K) due to the prevalence of strongly blocked conduction pathways

Negative differential transconductance in electrolyte-gated ruthenate

Energy Technology Data Exchange (ETDEWEB)

Hassan, Muhammad Umair [Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Center for Micro and Nano Devices, Department of Physics, COMSATS Institute of Information Technology, Park Road, Shehzad Town 44000, Islamabad (Pakistan); Dhoot, Anoop Singh, E-mail: asd24@cam.ac.uk [Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Wimbush, Stuart C. [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, P.O. Box 600, Wellington 6140 (New Zealand)

2015-01-19

We report on a study of electric field-induced doping of the highly conductive ruthenate SrRuO{sub 3} using an ionic liquid as the gate dielectric in a field-effect transistor configuration. Two distinct carrier transport regimes are identified for increasing positive gate voltage in thin (10 nm) films grown heteroepitaxially on SrTiO{sub 3} substrates. For V{sub g} = 2 V and lower, the sample shows an increased conductivity of up to 13%, as might be expected for electron doping of a metal. At higher V{sub g} = 2.5 V, we observe a large decrease in electrical conductivity of >20% (at 4.2 K) due to the prevalence of strongly blocked conduction pathways.

Coordination compounds of titanium, zirconium, tin, thorium and uranium

International Nuclear Information System (INIS)

Deshpande, S.G.; Jain, S.C.

1990-01-01

Reactions of isatin, furoic acid and picolinic acid have been carried out with titanium tetrachloride, tin tetrachloride, thorium tetrachloride, zirconyl chloride and uranyl nitrate. While 2:3(metal:ligand) type compounds of isatin have been obtained with Ti(IV) and Sn(IV), zirconium(IV), thorium(IV), and uranium(VI) do not react with the ligand under similar experimental conditions. Furoic acid (FAH) and picolinic acid(PicH) form various chloro furoates and picolinates when reacted with TiCl 4 , ZrOCl 2 and ThCl 4 , but do not react with SnCl 4 . The various compounds synthesised have been characterised on the basis of elemental analysis, infrared studies, conductivity and thermogravimetric measurements. (author). 1 tab., 10 refs

Biogeochemical investigations in areas of copper-tin mineralization in south-west England

Energy Technology Data Exchange (ETDEWEB)

Millman, A P

1957-01-01

Semi-quantitative methods of spectrographic analysis have been employed for the determination of Cu, Sn, Zn, Pb, and Ag in the leaves and twigs of a variety of trees growing in an area of copper-tin mineralization on the borders of Cornwall and Devon. The distribution of these ore metals in the soil profiles was also determined. Ore-negative (background) values have been derived for the trees and the soils, and these are compared with the results of earlier work in Southern Nigeria and Northern Rhodesia. 20 references, 4 tables.

Thermal stability of atomic layer deposited WCxNy electrodes for metal oxide semiconductor devices

Science.gov (United States)

Zonensain, Oren; Fadida, Sivan; Fisher, Ilanit; Gao, Juwen; Danek, Michal; Eizenberg, Moshe

2018-01-01

This study is a thorough investigation of the chemical, structural, and electrical stability of W based organo-metallic films, grown by atomic layer deposition, for future use as gate electrodes in advanced metal oxide semiconductor structures. In an earlier work, we have shown that high effective work-function (4.7 eV) was produced by nitrogen enriched films (WCxNy) dominated by W-N chemical bonding, and low effective work-function (4.2 eV) was produced by hydrogen plasma resulting in WCx films dominated by W-C chemical bonding. In the current work, we observe, using x-ray diffraction analysis, phase transformation of the tungsten carbide and tungsten nitride phases after 900 °C annealing to the cubic tungsten phase. Nitrogen diffusion is also observed and is analyzed with time-of-flight secondary ion mass spectroscopy. After this 900 °C anneal, WCxNy effective work function tunability is lost and effective work-function values of 4.7-4.8 eV are measured, similar to stable effective work function values measured for PVD TiN up to 900 °C anneal. All the observed changes after annealing are discussed and correlated to the observed change in the effective work function.

Association between Serum Heavy Metals Level and Cancer ...

African Journals Online (AJOL)

2018-06-11

Jun 11, 2018 ... metals level and cancer incidence in Darbandikhan and Kalar area,. Kurdistan region ..... In males, they were lung, leukemia, lymphoma, colorectal, prostate, bladder, ... lead, mercury, and tin activate the estrogen receptor,.

[Exposure to metal compounds in occupational galvanic processes].

Science.gov (United States)

Surgiewicz, Jolanta; Domański, Wojciech

2006-01-01

Occupational galvanic processes are provided in more than 600 small and medium enterprises in Poland. Workers who deal with galvanic coating are exposed to heavy metal compounds: tin, silver, copper and zinc. Some of them are carcinogenic, for example, hexavalent chromium compounds, nickel and cadmium compounds. Research covered several tens of workstations involved in chrome, nickel, zinc, tin, silver, copper and cadmium plating. Compounds of metals present in the air were determined: Cr, Ni, Cd, Sn, Ag--by atomic absorption spectrometry with electrothermal atomization (ET-AAS) and Zn--by atomic absorption spectrometry with flame atomization (F-AAS). The biggest metal concentrations--of silver and copper--were found at workstations of copper, brass, cadmium, nickel and chrome plating, conducted at the same time. Significant concentrations of copper were found at workstations of maintenance bathing and neutralizing of sewage. The concentrations of metals did not exceed Polish MAC values. MAC values were not exceeded for carcinogenic chromium(VI), nickel or cadmium, either. In galvanic processes there was no hazard related to single metals or their compounds, even carcinogenic ones. Combined exposure indicators for metals at each workstation did not exceed 1, either. However, if there are even small quantities of carcinogenic agents, health results should always be taken into consideration.

Sulfated tin oxide (STO – Structural properties and application in catalysis: A review

Directory of Open Access Journals (Sweden)

Ravi Varala

2016-07-01

Full Text Available Catalysis is an important area of chemistry, with an extensive amount of work going on in this area of sciences, toward synthesis and evaluation of newer catalysts. There are many reports for different conversion reactions such as oxidation, reduction, coupling, alkylation, and acylation for which various catalysts have been used such as mixed metal oxides, metal nanoparticles, metal organic complexes and many others. Among the many catalysts reported, the one catalyst that caught our attention due to its exploitation for a plethora of organic conversions is the sulfated tin oxide (STO, which is due to the low cost, greater stability and high efficiency of the catalyst. In this review, we have attempted to compile data about the structural properties of STO, and its applications as catalysts in various organic synthesis are presented. The literature data up to 2014 were collected and considered for the review.

Tin-Containing Silicates: Identification of a Glycolytic Pathway via 3-Deoxyglucosone

DEFF Research Database (Denmark)

Tolborg, Søren; Meier, Sebastian; Sádaba, I.

2016-01-01

a cascade of four to five sequential steps. Currently, there is a limited understanding of the competing glycolytic pathways within these systems. Here we identify dehydration of glucose to 3-deoxyglucosone as an important pathway that occurs in addition to retro-aldol reaction of hexoses when using tin......-containing silicates. It is possible to influence the relative carbon flux through these pathways by controlling the amount of alkali metal salts present in the reaction mixture. In the absence of added potassium carbonate, at least 15–30% carbon flux via 3-deoxyglucosone is observed. Addition of just a few ppm...

Microstructure and growth mechanism of tin whiskers on RESn3 compounds

International Nuclear Information System (INIS)

Li Caifu; Liu Zhiquan

2013-01-01

Graphical abstract: Large amount of intact tin whiskers were firstly prepared without post handling, and their microstructures were investigated systematically with TEM. A growth model was proposed to explain the observed growth characteristics from Sn–RE alloys. - Abstract: An exclusive method was developed to prepare intact tin whiskers as transmission electron microscope specimens, and with this technique in situ observation of tin whisker growth from RESn 3 (RE = Nd, La, Ce) film specimen was first achieved. Electron irradiation was discovered to have an effect on the growth of a tin whisker through its root. Large quantities of tin whiskers with diameters from 20 nm to 10 μm and lengths ranging from 50 nm to 500 μm were formed at a growth rate of 0.1–1.8 nm s −1 on the surface of RESn 3 compounds. Most (>85%) of these tin whiskers have preferred growth directions of 〈1 0 0〉, 〈0 0 1〉, 〈1 0 1〉 and 〈1 0 3〉, as determined by statistics. This kind of tin whisker is single-crystal β-Sn even if it has growth striations, steps and kinks, and no dislocations or twin or grain boundaries were observed within the whisker body. RESn 3 compounds undergo selective oxidation during whisker growth, and the oxidation provides continuous tin atoms for tin whisker growth until they are exhausted. The driving force for whisker growth is the compressive stress resulting from the restriction of the massive volume expansion (38–43%) during the oxidation by the surface RE(OH) 3 layer. Tin atoms diffuse and flow to feed the continuous growth of tin whiskers under a compressive stress gradient formed from the extrusion of tin atoms/clusters at weak points on the surface RE(OH) 3 layers. A growth model was proposed to discuss the characteristics and growth mechanism of tin whiskers from RESn 3 compounds.

Area efficient digital logic NOT gate using single electron box (SEB

Directory of Open Access Journals (Sweden)

Bahrepour Davoud

2017-01-01

Full Text Available The continuing scaling down of complementary metal oxide semiconductor (CMOS has led researchers to build new devices with nano dimensions, whose behavior will be interpreted based on quantum mechanics. Single-electron devices (SEDs are promising candidates for future VLSI applications, due to their ultra small dimensions and lower power consumption. In most SED based digital logic designs, a single gate is introduced and its performance discussed. While in the SED based circuits the fan out of designed gate circuit should be considered and measured. In the other words, cascaded SED based designs must work properly so that the next stage(s should be driven by the previous stage. In this paper, previously NOT gate based on single electron box (SEB which is an important structure in SED technology, is reviewed in order to obtain correct operation in series connections. The correct operation of the NOT gate is investigated in a buffer circuit which uses two connected NOT gate in series. Then, for achieving better performance the designed buffer circuit is improved by the use of scaling process.

A Grand Challenge for CMOS Scaling: Alternate Gate Dielectrics

Science.gov (United States)

Wallace, Robert M.

2001-03-01

Many materials systems are currently under consideration as potential replacements for SiO2 as the gate dielectric material for sub-0.13 um complementary metal oxide semiconductor (CMOS) technology. The prospect of replacing SiO2 is a formidable task because the alternate gate dielectric must provide many properties that are, at a minimum, comparable to those of SiO2 yet with a much higher permittivity. A systematic examination of the required performance of gate dielectrics suggests that the key properties to consider in the selection an alternative gate dielectric candidate are (a) permittivity, band gap and band alignment to silicon, (b) thermodynamic stability, (c) film morphology, (d) interface quality, (e) compatibility with the current or expected materials to be used in processing for CMOS devices, (f) process compatibility, and (g) reliability. Many dielectrics appear favorable in some of these areas, but very few materials are promising with respect to all of these guidelines. We will review the performance requirements for materials associated with CMOS scaling, the challenges associated with these requirements, and the state-of-the-art in current research for alternate gate dielectrics. The requirements for process integration compatibility are remarkably demanding, and any serious candidates will emerge only through continued, intensive investigation.

Gating system optimization of low pressure casting A356 aluminum alloy intake manifold based on numerical simulation

Directory of Open Access Journals (Sweden)

Jiang Wenming

2014-03-01

Full Text Available To eliminate the shrinkage porosity in low pressure casting of an A356 aluminum alloy intake manifold casting, numerical simulation on filling and solidification processes of the casting was carried out using the ProCAST software. The gating system of the casting is optimized according to the simulation results. Results show that when the gating system consists of only one sprue, the filling of the molten metal is not stable; and the casting does not follow the sequence solidification, and many shrinkage porosities are observed through the casting. After the gating system is improved by adding one runner and two in-gates, the filling time is prolonged from 4.0 s to 4.5 s, the filling of molten metal becomes stable, but this casting does not follow the sequence solidification either. Some shrinkage porosity is also observed in the hot spots of the casting. When the gating system was further improved by adding risers and chill to the hot spots of the casting, the shrinkage porosity defects were eliminated completely. Finally, by using the optimized gating system the A356 aluminum alloy intake manifold casting with integrated shape and smooth surface as well as dense microstructure was successfully produced.

NASA GSFC Tin Whisker Homepage http://nepp.nasa.gov/whisker

Science.gov (United States)

Shaw, Harry

2000-01-01

The NASA GSFC Tin Whisker Homepage provides general information and GSFC Code 562 experimentation results regarding the well known phenomenon of tin whisker formation from pure tin plated substrates. The objective of this www site is to provide a central repository for information pertaining to this phenomenon and to provide status of the GSFC experiments to understand the behavior of tin whiskers in space environments. The Tin Whisker www site is produced by Code 562. This www site does not provide information pertaining to patented or proprietary information. All of the information contained in this www site is at the level of that produced by industry and university researchers and is published at international conferences.

CONCURRENT CONTACT SENSITIZATION TO METALS IN DENTAL EXPOSURES

Directory of Open Access Journals (Sweden)

Maya Lyapina

2018-03-01

Full Text Available Purpose: Sensitization to metals is a significant problem for both dental patients treated with dental materials and for dental professionals in occupational exposures. The purpose of the present study was to evaluate the incidence of concurrent contact sensitization to relevant for dental practice metals among students of dental medicine, students from dental technician school, dental professionals and patients. Material and Methods: A total of 128 participants were included in the study. All of them were patch-tested with nickel, cobalt, copper, potassium dichromate, palladium, aluminium, gold and tin. The results were subject to statistical analysis (p < 0.05. Results: For the whole studied population, potassium dichromate exhibited concomitant reactivity most often; copper and tin also often manifested co-reactivity. For the groups, exposed in dental practice, potassium dichromate and tin were outlined as the most often co-reacting metal allergens, but statistical significance concerning the co-sensitization to copper and the other metals was established only for aluminium. An increased incidence and OR for concomitant sensitization to cobalt and nickel was established in the group of dental students; to copper and nickel - in the control group; to palladium and nickel - in the group of dental professionals, the group of students of dental medicine and in the control group; to potassium dichromate and cobalt - in the group of dental students; to copper and palladium - in the control group of dental patients; to potassium dichromate and copper - in the group of dental professionals; to copper and aluminum - in the groups of students from dental technician school and of dental professionals; to copper and gold - in the groups of dental professionals and in the group of dental patients; to potassium dichromate and aluminum - in the group of dental professionals; to potassium dichromate and gold - in the group of dental professionals, and to

How thin barrier metal can be used to prevent Co diffusion in the modern integrated circuits?

International Nuclear Information System (INIS)

Dixit, Hemant; Konar, Aniruddha; Pandey, Rajan; Ethirajan, Tamilmani

2017-01-01

In modern integrated circuits (ICs), billions of transistors are connected to each other via thin metal layers (e.g. copper, cobalt, etc) known as interconnects. At elevated process temperatures, inter-diffusion of atomic species can occur among these metal layers, causing sub-optimal performance of interconnects, which may lead to the failure of an IC. Thus, typically a thin barrier metal layer is used to prevent the inter-diffusion of atomic species within interconnects. For ICs with sub-10 nm transistors (10 nm technology node), the design rule (thickness scaling) demands the thinnest possible barrier layer. Therefore, here we investigate the critical thickness of a titanium–nitride (TiN) barrier that can prevent the cobalt diffusion using multi-scale modeling and simulations. First, we compute the Co diffusion barrier in crystalline and amorphous TiN with the nudged elastic band method within first-principles density functional theory simulations. Later, using the calculated activation energy barriers, we quantify the Co diffusion length in the TiN metal layer with the help of kinetic Monte Carlo simulations. Such a multi-scale modelling approach yields an exact critical thickness of the metal layer sufficient to prevent the Co diffusion in IC interconnects. We obtain a diffusion length of a maximum of 2 nm for a typical process of thermal annealing at 400 °C for 30 min. Our study thus provides useful physical insights for the Co diffusion in the TiN layer and further quantifies the critical thickness (∼2 nm) to which the metal barrier layer can be thinned down for sub-10 nm ICs. (paper)

How thin barrier metal can be used to prevent Co diffusion in the modern integrated circuits?

Science.gov (United States)

Dixit, Hemant; Konar, Aniruddha; Pandey, Rajan; Ethirajan, Tamilmani

2017-11-01

In modern integrated circuits (ICs), billions of transistors are connected to each other via thin metal layers (e.g. copper, cobalt, etc) known as interconnects. At elevated process temperatures, inter-diffusion of atomic species can occur among these metal layers, causing sub-optimal performance of interconnects, which may lead to the failure of an IC. Thus, typically a thin barrier metal layer is used to prevent the inter-diffusion of atomic species within interconnects. For ICs with sub-10 nm transistors (10 nm technology node), the design rule (thickness scaling) demands the thinnest possible barrier layer. Therefore, here we investigate the critical thickness of a titanium-nitride (TiN) barrier that can prevent the cobalt diffusion using multi-scale modeling and simulations. First, we compute the Co diffusion barrier in crystalline and amorphous TiN with the nudged elastic band method within first-principles density functional theory simulations. Later, using the calculated activation energy barriers, we quantify the Co diffusion length in the TiN metal layer with the help of kinetic Monte Carlo simulations. Such a multi-scale modelling approach yields an exact critical thickness of the metal layer sufficient to prevent the Co diffusion in IC interconnects. We obtain a diffusion length of a maximum of 2 nm for a typical process of thermal annealing at 400 °C for 30 min. Our study thus provides useful physical insights for the Co diffusion in the TiN layer and further quantifies the critical thickness (~2 nm) to which the metal barrier layer can be thinned down for sub-10 nm ICs.

Atomic dynamics of tin nanoparticles embedded into porous glass

Energy Technology Data Exchange (ETDEWEB)

Parshin, P. P.; Zemlyanov, M. G., E-mail: zeml@isssph.kiae.ru; Panova, G. Kh.; Shikov, A. A. [Russian Research Centre Kurchatov Institute (Russian Federation); Kumzerov, Yu. A.; Naberezhnov, A. A. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Sergueev, I.; Crichton, W. [European Synchrotron Radiation Facility (France); Chumakov, A. I. [Russian Research Centre Kurchatov Institute (Russian Federation); Rueffer, R. [European Synchrotron Radiation Facility (France)

2012-03-15

The method of resonant nuclear inelastic absorption of synchrotron radiation has been used to study the phonon spectrum for tin nanoparticles (with a natural isotope mixture) embedded into a porous glassy (silica) matrix with an average pore diameter of 7 nm in comparison to the analogous spectrum of bulk tin enriched with {sup 119}Sn isotope. Differences between the spectra have been observed, which are related to both the dimensional effects and specific structural features of the porous glass-tin nanocomposite. Peculiarities in the dynamics of tin atoms embedded into nanopores of glass are interpreted in terms of a qualitative model of the nanocomposite structure.

Atomic dynamics of tin nanoparticles embedded into porous glass

International Nuclear Information System (INIS)

Parshin, P. P.; Zemlyanov, M. G.; Panova, G. Kh.; Shikov, A. A.; Kumzerov, Yu. A.; Naberezhnov, A. A.; Sergueev, I.; Crichton, W.; Chumakov, A. I.; Rüffer, R.

2012-01-01

The method of resonant nuclear inelastic absorption of synchrotron radiation has been used to study the phonon spectrum for tin nanoparticles (with a natural isotope mixture) embedded into a porous glassy (silica) matrix with an average pore diameter of 7 nm in comparison to the analogous spectrum of bulk tin enriched with 119 Sn isotope. Differences between the spectra have been observed, which are related to both the dimensional effects and specific structural features of the porous glass-tin nanocomposite. Peculiarities in the dynamics of tin atoms embedded into nanopores of glass are interpreted in terms of a qualitative model of the nanocomposite structure.

Low temperature plasma-enhanced ALD TiN ultrathin films for Hf{sub 0.5}Zr{sub 0.5}O{sub 2}-based ferroelectric MIM structures

Energy Technology Data Exchange (ETDEWEB)

Kozodaev, M.G.; Chernikova, A.G.; Markeev, A.M. [Moscow Institute of Physics and Technology, Institutsky Lane 9, Dolgoprudny, Moscow Region 141700 (Russian Federation); Lebedinskii, Y.Y. [Moscow Institute of Physics and Technology, Institutsky Lane 9, Dolgoprudny, Moscow Region 141700 (Russian Federation); National Research Nuclear University MEPhI, Moscow Engineering Physics Institute, Kashirskoye Shosse 31, 115409 Moscow (Russian Federation); Polyakov, S.N. [Technological Institute for Superhard and Novel Carbon Materials, Tsentral' naya str. 7a, 142190, Troitsk, Moscow (Russian Federation)

2017-06-15

In this work chemical and electrical properties of TiN films, grown by low temperature plasma-enhanced atomic layer deposition (PE-ALD) process from TiCl{sub 4} and NH{sub 3}, were investigated. Electrical resistivity as low as 250 μOhm x cm, as well as the lowest Cl impurity content, was achieved at 320 C. Full-ALD Hf{sub 0.5}Zr{sub 0.5}O{sub 2}-based metal-ferroelectric-metal capacitor with TiN electrodes was fabricated and its electrical properties were investigated. It was also shown that the proposed PE-ALD process provides an early film continuity, which was confirmed by ultrathin fully continuous film growth. Such ultrathin (3 nm) and fully continuous TiN film was also successfully implemented as the top electrode to Hf{sub 0.5}Zr{sub 0.5}O{sub 2}-based ferroelectric capacitor. Angle-resolved X-ray photoelectron spectroscopy (AR-XPS) was used for its thickness determination and a visible wake-up effect in underlying Hf{sub 0.5}Zr{sub 0.5}O{sub 2} layer was clearly observed. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Organic derivatives of tin (II/IV): Investigation of their structure

Energy Technology Data Exchange (ETDEWEB)

Szirtes, L., E-mail: szirtes@iki.kfki.h [Institute of Isotopes of the Hungarian Academy of Sciences, Budapest H-1525, P.O. Box 77 (Hungary); Megyeri, J., E-mail: megyeri@iki.kfki.h [Institute of Isotopes of the Hungarian Academy of Sciences, Budapest H-1525, P.O. Box 77 (Hungary); Kuzmann, E. [Laboratory of Nuclear Chemistry, CRC of the Hungarian Academy of Science at Eoetvoes University, H-1518 Budapest, P.O. Box 32 (Hungary); Beck, A. [Institute of Isotopes of the Hungarian Academy of Sciences, Budapest H-1525, P.O. Box 77 (Hungary)

2011-07-15

The structures of tin(II)-oxalate, tin(IV)Na-EDTA and tin(IV)Na{sub 8}-inositol hexaphosphate were investigated using XRD analysis. Samples were identified using the Moessbauer study, thermal analysis and FTIR spectrometry. The Moessbauer study determined two different oxidation states of tin atoms, and consequently two different tin surroundings in the end products. The tin oxalate was found to be orthorhombic with space group Pnma, a=9.2066(3) A, b=9.7590(1) A, c=13.1848(5) A, V=1184.62 A{sup 3} and Z=8. SnNa-EDTA was found to be monoclinic with space group P2{sub 1}/c{sub 1}, a=10.7544(3) A, b=10.1455(3) A, c=16.5130(6) A, {beta}=98.59(2){sup o}, V=1781.50(4) A{sup 3} and Z=4. Sn(C{sub 6}H{sub 6}Na{sub 8}O{sub 24}P{sub 6}) was found to be amorphous.

χ{sup (3)} measurements of axial ligand modified high valent tin(IV) porphyrins using degenarete four wave mixing at 532nm

Energy Technology Data Exchange (ETDEWEB)

Narendran, N. K. Siji, E-mail: sijinarendran@gmail.com; Chandrasekharan, K. [Laser and nonlinear optics laboratory, Department of Physics, National Institute of Technology Calicut, Calicut-673601, Kerala (India); Soman, Rahul; Arunkumar, Chellaiah [Bioinorganic materials laboratory, Department of Chemistry, National Institute of Technology Calicut, Calicut-673601, Kerala (India); Sudheesh, P. [Department of Physics, VTM NSS College, Dhanuvachapuram, Thiruvananthapuram (India)

2014-10-15

Porphyrins and metalloporphyrins are unique class of molecules for Nonlinear Optical applications because of their unique structure of altering the central metal atom, large extended π-system, high thermal stability, tunable shape, symmetry and synthetic versatility Here, we report χ{sup (3)} Measurements of a simple phenyl porphyrins and its highvalent tin(IV) porphyrins with Bromination characterized by UV-Visible spectroscopic method. In this study, we employed the Degenerate Four Wave Mixing technique using forward Boxcar geometry with an Nd:YAG nano second pulsed laser as source and it was found that the tin(IV) porphyrin with Bromination exhibits good χ{sup (3)} value and figure of merit.

Proton transport properties of tin phosphate, chromotropic acid ...

Indian Academy of Sciences (India)

The functionalized materials of tin (IV) phosphate (SnP) like chromotropic acid anchored tin ... elemental analysis (ICP–AES), thermal analysis, X-ray analysis and FTIR spectroscopy. .... nal level below 1 V, interfaced to a minicomputer for data.

Continuous adjustment of threshold voltage in carbon nanotube field-effect transistors through gate engineering

Science.gov (United States)

Zhong, Donglai; Zhao, Chenyi; Liu, Lijun; Zhang, Zhiyong; Peng, Lian-Mao

2018-04-01

In this letter, we report a gate engineering method to adjust threshold voltage of carbon nanotube (CNT) based field-effect transistors (FETs) continuously in a wide range, which makes the application of CNT FETs especially in digital integrated circuits (ICs) easier. Top-gated FETs are fabricated using solution-processed CNT network films with stacking Pd and Sc films as gate electrodes. By decreasing the thickness of the lower layer metal (Pd) from 20 nm to zero, the effective work function of the gate decreases, thus tuning the threshold voltage (Vt) of CNT FETs from -1.0 V to 0.2 V. The continuous adjustment of threshold voltage through gate engineering lays a solid foundation for multi-threshold technology in CNT based ICs, which then can simultaneously provide high performance and low power circuit modules on one chip.

Studies on Nanocrystalline TiN Coatings Prepared by Reactive Plasma Spraying

Directory of Open Access Journals (Sweden)

Dong Yanchun

2008-01-01

Full Text Available Titanium nitride (TiN coatings with nanostructure were prepared on the surface of 45 steel (Fe-0.45%C via reactive plasma spraying (denoted as RPS Ti powders using spraying gun with self-made reactive chamber. The microstructural characterization, phases constitute, grain size, microhardness, and wear resistance of TiN coatings were systematically investigated. The grain size was obtained through calculation using the Scherrer formula and observed by TEM. The results of X-ray diffraction and electron diffraction indicated that the TiN is main phase of the TiN coating. The forming mechanism of the nano-TiN was characterized by analyzing the SEM morphologies of surface of TiN coating and TiN drops sprayed on the surface of glass, and observing the temperature and velocity of plasma jet using Spray Watch. The tribological properties of the coating under nonlubricated condition were tested and compared with those of the AISI M2 high-speed steel and Al2O3 coating. The results have shown that the RPS TiN coating presents better wear resistance than the M2 high-speed steel and Al2O3 coating under nonlubricated condition. The microhardness of the cross-section and longitudinal section of the TiN coating was tested. The highest hardness of the cross-section of TiN coating is 1735.43HV100 g.

Metal Vapor Arcing Risk Assessment Tool

Science.gov (United States)

Hill, Monika C.; Leidecker, Henning W.

2010-01-01

The Tin Whisker Metal Vapor Arcing Risk Assessment Tool has been designed to evaluate the risk of metal vapor arcing and to help facilitate a decision toward a researched risk disposition. Users can evaluate a system without having to open up the hardware. This process allows for investigating components at risk rather than spending time and money analyzing every component. The tool points to a risk level and provides direction for appropriate action and documentation.

Atomic Layer Deposition of Gallium Oxide Films as Gate Dielectrics in AlGaN/GaN Metal-Oxide-Semiconductor High-Electron-Mobility Transistors.

Science.gov (United States)

Shih, Huan-Yu; Chu, Fu-Chuan; Das, Atanu; Lee, Chia-Yu; Chen, Ming-Jang; Lin, Ray-Ming

2016-12-01

In this study, films of gallium oxide (Ga2O3) were prepared through remote plasma atomic layer deposition (RP-ALD) using triethylgallium and oxygen plasma. The chemical composition and optical properties of the Ga2O3 thin films were investigated; the saturation growth displayed a linear dependence with respect to the number of ALD cycles. These uniform ALD films exhibited excellent uniformity and smooth Ga2O3-GaN interfaces. An ALD Ga2O3 film was then used as the gate dielectric and surface passivation layer in a metal-oxide-semiconductor high-electron-mobility transistor (MOS-HEMT), which exhibited device performance superior to that of a corresponding conventional Schottky gate HEMT. Under similar bias conditions, the gate leakage currents of the MOS-HEMT were two orders of magnitude lower than those of the conventional HEMT, with the power-added efficiency enhanced by up to 9 %. The subthreshold swing and effective interfacial state density of the MOS-HEMT were 78 mV decade(-1) and 3.62 × 10(11) eV(-1) cm(-2), respectively. The direct-current and radio-frequency performances of the MOS-HEMT device were greater than those of the conventional HEMT. In addition, the flicker noise of the MOS-HEMT was lower than that of the conventional HEMT.

NiCo2O4@TiN Core-shell Electrodes through Conformal Atomic Layer Deposition for All-solid-state Supercapacitors

KAUST Repository

Wang, Renqi

2016-03-04

Ternary transition metal oxides such as NiCo2O4 show great promise as supercapacitor electrode materials. However, the unsatisfactory rate performance of NiCo2O4 may prove to be a major hurdle to its commercial usage. Herein, we report the development of NiCo2O4@TiN core–shell nanostructures for all-solid-state supercapacitors with significantly enhanced rate capability. We demonstrate that a thin layer of TiN conformally grown by atomic layer deposition (ALD) on NiCo2O4 nanofiber arrays plays a key role in improving their electrical conductivity, mechanical stability, and rate performance. Fabricated using the hybrid NiCo2O4@TiN electrodes, the symmetric all-solid-state supercapacitor exhibited an impressive stack power density of 58.205 mW cm−3 at a stack energy density of 0.061 mWh cm−3. To the best of our knowledge, these values are the highest of any NiCo2O4-based all-solid-state supercapacitor reported. Additionally, the resulting NiCo2O4@TiN all-solid-state device displayed outstanding cycling stability by retaining 70% of its original capacitance after 20,000 cycles at a high current density of 10 mA cm−2. These results illustrate the promise of ALD-assisted hybrid NiCo2O4@TiN electrodes for sustainable and integrated energy storage applications.

NiCo2O4@TiN Core-shell Electrodes through Conformal Atomic Layer Deposition for All-solid-state Supercapacitors

KAUST Repository

Wang, Renqi; Xia, Chuan; Wei, Nini; Alshareef, Husam N.

2016-01-01

Ternary transition metal oxides such as NiCo2O4 show great promise as supercapacitor electrode materials. However, the unsatisfactory rate performance of NiCo2O4 may prove to be a major hurdle to its commercial usage. Herein, we report the development of NiCo2O4@TiN core–shell nanostructures for all-solid-state supercapacitors with significantly enhanced rate capability. We demonstrate that a thin layer of TiN conformally grown by atomic layer deposition (ALD) on NiCo2O4 nanofiber arrays plays a key role in improving their electrical conductivity, mechanical stability, and rate performance. Fabricated using the hybrid NiCo2O4@TiN electrodes, the symmetric all-solid-state supercapacitor exhibited an impressive stack power density of 58.205 mW cm−3 at a stack energy density of 0.061 mWh cm−3. To the best of our knowledge, these values are the highest of any NiCo2O4-based all-solid-state supercapacitor reported. Additionally, the resulting NiCo2O4@TiN all-solid-state device displayed outstanding cycling stability by retaining 70% of its original capacitance after 20,000 cycles at a high current density of 10 mA cm−2. These results illustrate the promise of ALD-assisted hybrid NiCo2O4@TiN electrodes for sustainable and integrated energy storage applications.

Liquid–Solid Dual-Gate Organic Transistors with Tunable Threshold Voltage for Cell Sensing

KAUST Repository

Zhang, Yu

2017-10-17

Liquid electrolyte-gated organic field effect transistors and organic electrochemical transistors have recently emerged as powerful technology platforms for sensing and simulation of living cells and organisms. For such applications, the transistors are operated at a gate voltage around or below 0.3 V because prolonged application of a higher voltage bias can lead to membrane rupturing and cell death. This constraint often prevents the operation of the transistors at their maximum transconductance or most sensitive regime. Here, we exploit a solid–liquid dual-gate organic transistor structure, where the threshold voltage of the liquid-gated conduction channel is controlled by an additional gate that is separated from the channel by a metal-oxide gate dielectric. With this design, the threshold voltage of the “sensing channel” can be linearly tuned in a voltage window exceeding 0.4 V. We have demonstrated that the dual-gate structure enables a much better sensor response to the detachment of human mesenchymal stem cells. In general, the capability of tuning the optimal sensing bias will not only improve the device performance but also broaden the material selection for cell-based organic bioelectronics.

Liquid-Solid Dual-Gate Organic Transistors with Tunable Threshold Voltage for Cell Sensing.

Science.gov (United States)

Zhang, Yu; Li, Jun; Li, Rui; Sbircea, Dan-Tiberiu; Giovannitti, Alexander; Xu, Junling; Xu, Huihua; Zhou, Guodong; Bian, Liming; McCulloch, Iain; Zhao, Ni

2017-11-08

Liquid electrolyte-gated organic field effect transistors and organic electrochemical transistors have recently emerged as powerful technology platforms for sensing and simulation of living cells and organisms. For such applications, the transistors are operated at a gate voltage around or below 0.3 V because prolonged application of a higher voltage bias can lead to membrane rupturing and cell death. This constraint often prevents the operation of the transistors at their maximum transconductance or most sensitive regime. Here, we exploit a solid-liquid dual-gate organic transistor structure, where the threshold voltage of the liquid-gated conduction channel is controlled by an additional gate that is separated from the channel by a metal-oxide gate dielectric. With this design, the threshold voltage of the "sensing channel" can be linearly tuned in a voltage window exceeding 0.4 V. We have demonstrated that the dual-gate structure enables a much better sensor response to the detachment of human mesenchymal stem cells. In general, the capability of tuning the optimal sensing bias will not only improve the device performance but also broaden the material selection for cell-based organic bioelectronics.

Manufacturing of glass from tin mining tailings in Bolivia

International Nuclear Information System (INIS)

Arancibia, J. r. H.; Alfonso, P.; Garcia-Valles, M.; Martinez, S.; Parcerisa, D.; Canet, C.; Romero, F. M.

2013-01-01

Tailings from mining activities in Bolivia represent an environmental problem. In the vicinity of the tin mines of Llallagua, Potosi department, there are large dumps and tailings. We present a study of the use of these wastes as raw materials for the manufacture of glass. This procedure aims to contribute to environmental remediation of mining areas through the vitrification, a process which offers an alternative for stabilization of hazardous waste. In addition, the marketing of the obtained product would provide an additional income to the mining areas. For this study three samples of mining waste, with grain size between sand and silt, were used. The chemical composition of these raw materials, determined by X-ray fluorescence, is granitic, with high contents of heavy metals. On the basis of its composition, glass were made from silica glass by adding CaCO 3 and Na 2 CO 3 . The thermal cycle has been determined from TDA. Tg values of glass range from 626 degree centigrade to 709 degree centigrade. Leaching tests of the obtained glasses confirm their capacity to retain heavy metals. (Author)

Analytical modeling and simulation of subthreshold behavior in nanoscale dual material gate AlGaN/GaN HEMT

Science.gov (United States)

Kumar, Sona P.; Agrawal, Anju; Chaujar, Rishu; Gupta, Mridula; Gupta, R. S.

2008-07-01

A two-dimensional (2-D) analytical model for a Dual Material Gate (DMG) AlGaN/GaN High Electron Mobility Transistor (HEMT) has been developed to demonstrate the unique attributes of this device structure in suppressing short channel effects (SCEs). The model accurately predicts the channel potential, electric field variation along the channel, and sub-threshold drain current, taking into account the effect of lengths of the two gate metals, their work functions, barrier layer thicknesses, and applied drain biases. It is seen that the SCEs and hot carrier effects in DMG AlGaN/GaN HEMT are suppressed due to the work function difference of the two metal gates, thereby screening the drain potential variations by the gate near the drain. Besides, a more uniform electric field along the channel leads to improved carrier transport efficiency. The accuracy of the results obtained from our analytical model has been verified using ATLAS device simulations.

Study of degradation processes of metals used in some artworks from the cultural heritage of Andalusia, Spain

Energy Technology Data Exchange (ETDEWEB)

Duran, A.; Herrera, L. K.; Jimenez de Haro, M. C.; Pere-Rodriguez, J. L.; Justo, A.

2009-07-01

The study of the alteration processes of metals, such as lead, bronze, iron and tin-mercury alloys, used in some of the most important chosen artefacts of Andalusian Cultural Heritage is the main objective of this paper. Hydrocerussite and cerussete were detected in lead seals stored in a hole of cardboard. Bronze is altered to atacamite by environmental contamination, which is also responsible for the formation of rust from iron. Corrosion of the tin-mercury surface of amalgam mirrors produces tin monoxide and tin dioxide and releases liquid mercury from the solid phase. (Author) 38 refs.

3D modeling of dual-gate FinFET.

Science.gov (United States)

Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John

2012-11-13

The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

Simulation of 50-nm Gate Graphene Nanoribbon Transistors

Directory of Open Access Journals (Sweden)

Cedric Nanmeni Bondja

2016-01-01

Full Text Available An approach to simulate the steady-state and small-signal behavior of GNR MOSFETs (graphene nanoribbon metal-semiconductor-oxide field-effect transistor is presented. GNR material parameters and a method to account for the density of states of one-dimensional systems like GNRs are implemented in a commercial device simulator. This modified tool is used to calculate the current-voltage characteristics as well the cutoff frequency fT and the maximum frequency of oscillation fmax of GNR MOSFETs. Exemplarily, we consider 50-nm gate GNR MOSFETs with N = 7 armchair GNR channels and examine two transistor configurations. The first configuration is a simplified MOSFET structure with a single GNR channel as usually studied by other groups. Furthermore, and for the first time in the literature, we study in detail a transistor structure with multiple parallel GNR channels and interribbon gates. It is shown that the calculated fT of GNR MOSFETs is significantly lower than that of GFETs (FET with gapless large-area graphene channel with comparable gate length due to the mobility degradation in GNRs. On the other hand, GNR MOSFETs show much higher fmax compared to experimental GFETs due the semiconducting nature of the GNR channels and the resulting better saturation of the drain current. Finally, it is shown that the gate control in FETs with multiple parallel GNR channels is improved while the cutoff frequency is degraded compared to single-channel GNR MOSFETs due to parasitic capacitances of the interribbon gates.

Local gate control in carbon nanotube quantum devices

Science.gov (United States)

Biercuk, Michael Jordan

This thesis presents transport measurements of carbon nanotube electronic devices operated in the quantum regime. Nanotubes are contacted by source and drain electrodes, and multiple lithographically-patterned electrostatic gates are aligned to each device. Transport measurements of device conductance or current as a function of local gate voltages reveal that local gates couple primarily to the proximal section of the nanotube, hence providing spatially localized control over carrier density along the nanotube length. Further, using several different techniques we are able to produce local depletion regions along the length of a tube. This phenomenon is explored in detail for different contact metals to the nanotube. We utilize local gating techniques to study multiple quantum dots in carbon nanotubes produced both by naturally occurring defects, and by the controlled application of voltages to depletion gates. We study double quantum dots in detail, where transport measurements reveal honeycomb charge stability diagrams. We extract values of energy-level spacings, capacitances, and interaction energies for this system, and demonstrate independent control over all relevant tunneling rates. We report rf-reflectometry measurements of gate-defined carbon nanotube quantum dots with integrated charge sensors. Aluminum rf-SETs are electrostatically coupled to carbon nanotube devices and detect single electron charging phenomena in the Coulomb blockade regime. Simultaneous correlated measurements of single electron charging are made using reflected rf power from the nanotube itself and from the rf-SET on microsecond time scales. We map charge stability diagrams for the nanotube quantum dot via charge sensing, observing Coulomb charging diamonds beyond the first order. Conductance measurements of carbon nanotubes containing gated local depletion regions exhibit plateaus as a function of gate voltage, spaced by approximately 1e2/h, the quantum of conductance for a single

TiN coated aluminum electrodes for DC high voltage electron guns

International Nuclear Information System (INIS)

Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

2015-01-01

Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloy (Ti-6Al-4V). Following gas conditioning, each TiN-coated aluminum electrode reached −225 kV bias voltage while generating less than 100 pA of field emission (<10 pA) using a 40 mm cathode/anode gap, corresponding to field strength of 13.7 MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ∼22.5 MV/m with field emission less than 100 pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes

Novel phases and superconductivity of tin sulfide compounds

Science.gov (United States)

Gonzalez, Joseph M.; Nguyen-Cong, Kien; Steele, Brad A.; Oleynik, Ivan I.

2018-05-01

Tin sulfides, SnxSy, are an important class of materials that are actively investigated as novel photovoltaic and water splitting materials. A first-principles evolutionary crystal structure search is performed with the goal of constructing the complete phase diagram of SnxSy and discovering new phases as well as new compounds of varying stoichiometry at ambient conditions and pressures up to 100 GPa. The ambient phase of SnS2 with P 3 ¯ m 1 symmetry remains stable up to 28 GPa. Another ambient phase, SnS, experiences a series of phase transformations including α-SnS to β-SnS at 9 GPa, followed by β-SnS to γ-SnS at 40 GPa. γ-SnS is a new high-pressure metallic phase with P m 3 ¯ m space group symmetry stable up to 100 GPa, which becomes a superconductor with a maximum Tc = 9.74 K at 40 GPa. Another new metallic compound, Sn3S4 with I 4 ¯ 3 d space group symmetry, is predicted to be stable at pressures above 15 GPa, which also becomes a superconductor with relatively high Tc = 21.9 K at 30 GPa.

A novel optical gating method for laser gated imaging

Science.gov (United States)

Ginat, Ran; Schneider, Ron; Zohar, Eyal; Nesher, Ofer

2013-06-01

For the past 15 years, Elbit Systems is developing time-resolved active laser-gated imaging (LGI) systems for various applications. Traditional LGI systems are based on high sensitive gated sensors, synchronized to pulsed laser sources. Elbit propriety multi-pulse per frame method, which is being implemented in LGI systems, improves significantly the imaging quality. A significant characteristic of the LGI is its ability to penetrate a disturbing media, such as rain, haze and some fog types. Current LGI systems are based on image intensifier (II) sensors, limiting the system in spectral response, image quality, reliability and cost. A novel propriety optical gating module was developed in Elbit, untying the dependency of LGI system on II. The optical gating module is not bounded to the radiance wavelength and positioned between the system optics and the sensor. This optical gating method supports the use of conventional solid state sensors. By selecting the appropriate solid state sensor, the new LGI systems can operate at any desired wavelength. In this paper we present the new gating method characteristics, performance and its advantages over the II gating method. The use of the gated imaging systems is described in a variety of applications, including results from latest field experiments.

Comprehensive study of gate-terminated and source-terminated field-plate 0.13 µm NMOS transistors

International Nuclear Information System (INIS)

Chiu, Hsien-Chin; Lin, Shao-Wei; Cheng, Chia-Shih; Wei, Chien-Cheng

2008-01-01

This study systematically investigated microwave noise, power and linearity characteristics of field-plate (FP) 0.13 µm CMOS transistors in which the field-plate metal is connected to the gate terminal and the source terminal. The gate-terminated FP NMOS (FP-G NMOS) provided the best noise figure (NF) at 6 GHz compared with standard devices and the source-terminated FP device (FP-S NMOS) as the lowest gate resistance (R g ) was obtained by this structure. By adopting the field-plate metal in NMOS, both FP-S and FP-G devices achieved higher current density at high gate bias voltages. Moreover, these two devices also had higher efficiency under high drain-to-source voltages at the high input power swing. The third-order inter-modulation product (IM3) is −39.4 dBm for FP-S NMOS at P in of −20 dBm; the corresponding values for FP-G and standard devices are −34.9 dBm and −37.3 dBm, respectively. Experimental results indicate that the FP-G architecture is suitable for low noise applications and FP-S is suitable for high power and high linearity operation

Using a Floating-Gate MOS Transistor as a Transducer in a MEMS Gas Sensing System

Directory of Open Access Journals (Sweden)

Gaspar Casados-Cruz

2010-11-01

Full Text Available Floating-gate MOS transistors have been widely used in diverse analog and digital applications. One of these is as a charge sensitive device in sensors for pH measurement in solutions or using gates with metals like Pd or Pt for hydrogen sensing. Efforts are being made to monolithically integrate sensors together with controlling and signal processing electronics using standard technologies. This can be achieved with the demonstrated compatibility between available CMOS technology and MEMS technology. In this paper an in-depth analysis is done regarding the reliability of floating-gate MOS transistors when charge produced by a chemical reaction between metallic oxide thin films with either reducing or oxidizing gases is present. These chemical reactions need temperatures around 200 °C or higher to take place, so thermal insulation of the sensing area must be assured for appropriate operation of the electronics at room temperature. The operation principle of the proposal here presented is confirmed by connecting the gate of a conventional MOS transistor in series with a Fe2O3 layer. It is shown that an electrochemical potential is present on the ferrite layer when reacting with propane.

Selective Recovery of Mushistonite from Gravity Tailings of Copper–Tin Minerals in Tajikistan

OpenAIRE

Lei Sun; Yuehua Hu; Wei Sun; Zhiyong Gao; Mengjie Tian

2017-01-01

Tajikistan has abundant copper–tin resources. In this study, mineralogical analysis of copper–tin ores from the Mushiston deposit of Tajikistan indicates that tin mainly occurred in mushistonite, cassiterite, and stannite, while copper mainly occurred in mushistonite, malachite, azurite, and stannite. The total grades of tin (Sn) and copper (Cu) were 0.65% and 0.66%, respectively, and the dissemination size of copper–tin minerals ranged from 4 μm to over 200 μm. Coarse particles of copper–tin...

Inorganic ion exchanger based on tin/titanium mixed oxide doped with europium to be used in radioactive waste

International Nuclear Information System (INIS)

Paganini, Paula P.; Felinto, Maria Claudia F.C.; Kodaira, Claudia A.; Brito, Hermi F.

2009-01-01

This work presents the results of synthesis and characterization of an inorganic ion exchanger based on tin/titanium mixed oxides doped with europium (SnO 2 /TiO 2 :Eu 3+ ) to be used in environmental field. The adsorption study of nickel was realized in this exchanger to recover the nickel metal which is in thorium-nickel alloys used as electrode of discharge lamps. The studied exchanger was synthesized by neutralization of tin chloride (IV) and titanium chloride (III) mixed solution and characterized by thermogravimetric measurement (TG), Differential Scanning Calorimetry (DSC), X-Ray Powder Diffraction (XRD), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM). The adsorption study showed that these inorganic ion exchangers are good materials to recovery nickel with high weight distribution ratios (Dw Ni 2+ ) and percent adsorption. (author)

Serializing off-the-shelf MOSFETs by Magnetically Coupling Their Gate Electrodes

DEFF Research Database (Denmark)

Dimopoulos, Emmanouil; Munk-Nielsen, Stig

2013-01-01

While the semiconductor industry struggles with the inherent trade-offs of solid-state devices, serialization of power switches, like the Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) or the Insulated Gate Bipolar Transistor (IGBT), has been proven to be an advantageous alternative...... to acquire a high-efficient, high-voltage, fast-switching device. More than twenty years of research, on the serialization of solid-state devices, have resulted into several different stacking concepts. Among the prevailing ones, the gate balancing core technique, which has demonstrated very good performance...... in strings of high-power IGBT modules. In this paper, the limitations of the gate balancing core technique, when employed to serialize low or medium power off-the-shelf switches, are identified via experimental results. A new design specification for the interwinding capacitance of the employed transformer...

Survey of heavy metals in the sediments of the Swartkops River ...

African Journals Online (AJOL)

Survey of heavy metals in the sediments of the Swartkops River Estuary, Port Elizabeth South Africa. Karen Binning, Dan Baird. Abstract. Elevated levels of heavy metals in the sediment can be a good indication of man-induced pollution. Concentrations of chrome, lead, zinc, titanium, manganese, strontium, copper and tin ...

Venting temperature determines surface chemistry of magnetron sputtered TiN films

Energy Technology Data Exchange (ETDEWEB)

Greczynski, G. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden); Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Mráz, S.; Schneider, J. M. [Materials Chemistry, RWTH Aachen University, Kopernikusstr. 10, D-52074 Aachen (Germany); Hultman, L. [Thin Film Physics Division, Department of Physics (IFM), Linköping University, SE-581 83 Linköping (Sweden)

2016-01-25

Surface properties of refractory ceramic transition metal nitride thin films grown by magnetron sputtering are essential for resistance towards oxidation necessary in all modern applications. Here, typically neglected factors, including exposure to residual process gases following the growth and the venting temperature T{sub v}, each affecting the surface chemistry, are addressed. It is demonstrated for the TiN model materials system that T{sub v} has a substantial effect on the composition and thickness-evolution of the reacted surface layer and should therefore be reported. The phenomena are also shown to have impact on the reliable surface characterization by x-ray photoelectron spectroscopy.

Initial growth and texture formation during reactive magnetron sputtering of TiN on Si(111)

CERN Document Server

Li, T Q; Tsuji, Y; Ohsawa, T; Komiyama, H

2002-01-01

The initial growth and texture formation mechanism of titanium nitride (TiN) films were investigated by depositing TiN films on (111) silicon substrates by using reactive magnetron sputtering of a Ti metallic target under a N sub 2 /Ar atmosphere, and then analyzing the films in detail by using transmission electron microscopy (TEM) and x-ray diffraction (XRD). Two power sources for the sputtering, dc and rf, were compared. At the initial growth stage, a continuous amorphous film containing randomly oriented nuclei was observed when the film thickness was about 3 nm. The nuclei grew and formed a polycrystalline layer when the film thickness was about 6 nm. As the film grew further, its orientation changed depending on the deposition conditions. For dc sputtering, the appearance of (111) or (200)-preferred orientations depended on the N sub 2 partial pressure, and the intensity of the preferred orientation increased with increasing film thickness. For rf sputtering, however, when the film thickness was small (...

The effects of Ti implantation on corrosion and adhesion of TiN coated stainless steel

Science.gov (United States)

Baba, K.; Nagata, S.; Hatada, R.; Daikoku, T.; Hasaka, M.

1993-06-01

Thin titanium nitride (TiN) films of 40 and 70 nm in thickness were deposited on austenitic-type 304 stainless steel substrates by a rf ion plating process, and these specimens were irradiated with 70 kV titanium ions at a fluence of 1 × 10 17/cm 2 by use of MEVVA IV metallic ion source at room temperature. After that TiN films of 2 μm were deposited by the same method. The results of X-ray photoelectron spectroscopy and Auger electron spectroscopy revealed that implanted titanium penetrated into the substrate and interfacial mixing was verified. The adhesion strength was estimated by a scratch test. It was found that ion implantation can enhance the adhesion strength between the film and the substrate. The corrosion resistance of the specimens was evaluated in aqueous solutions of sulfuric acid by an electrochemical method. Titanium implantation was extremely effective in suppressing the anodic dissolution of stainless steel.

Dynamic gating window for compensation of baseline shift in respiratory-gated radiation therapy

International Nuclear Information System (INIS)

Pepin, Eric W.; Wu Huanmei; Shirato, Hiroki

2011-01-01

Purpose: To analyze and evaluate the necessity and use of dynamic gating techniques for compensation of baseline shift during respiratory-gated radiation therapy of lung tumors. Methods: Motion tracking data from 30 lung tumors over 592 treatment fractions were analyzed for baseline shift. The finite state model (FSM) was used to identify the end-of-exhale (EOE) breathing phase throughout each treatment fraction. Using duty cycle as an evaluation metric, several methods of end-of-exhale dynamic gating were compared: An a posteriori ideal gating window, a predictive trend-line-based gating window, and a predictive weighted point-based gating window. These methods were evaluated for each of several gating window types: Superior/inferior (SI) gating, anterior/posterior beam, lateral beam, and 3D gating. Results: In the absence of dynamic gating techniques, SI gating gave a 39.6% duty cycle. The ideal SI gating window yielded a 41.5% duty cycle. The weight-based method of dynamic SI gating yielded a duty cycle of 36.2%. The trend-line-based method yielded a duty cycle of 34.0%. Conclusions: Dynamic gating was not broadly beneficial due to a breakdown of the FSM's ability to identify the EOE phase. When the EOE phase was well defined, dynamic gating showed an improvement over static-window gating.

Mechanisms for plasma etching of HfO{sub 2} gate stacks with Si selectivity and photoresist trimming

Energy Technology Data Exchange (ETDEWEB)

Shoeb, Juline; Kushner, Mark J. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States)

2009-11-15

To minimize leakage currents resulting from the thinning of the insulator in the gate stack of field effect transistors, high-dielectric constant (high-k) metal oxides, and HfO{sub 2} in particular, are being implemented as a replacement for SiO{sub 2}. To speed the rate of processing, it is desirable to etch the gate stack (e.g., metal gate, antireflection layers, and dielectric) in a single process while having selectivity to the underlying Si. Plasma etching using Ar/BCl{sub 3}/Cl{sub 2} mixtures effectively etches HfO{sub 2} while having good selectivity to Si. In this article, results from integrated reactor and feature scale modeling of gate-stack etching in Ar/BCl{sub 3}/Cl{sub 2} plasmas, preceded by photoresist trimming in Ar/O{sub 2} plasmas, are discussed. It was found that BCl{sub n} species react with HfO{sub 2}, which under ion impact, form volatile etch products such as B{sub m}OCl{sub n} and HfCl{sub n}. Selectivity to Si is achieved by creating Si-B bonding as a precursor to the deposition of a BCl{sub n} polymer which slows the etch rate relative to HfO{sub 2}. The low ion energies required to achieve this selectivity then challenge one to obtain highly anisotropic profiles in the metal gate portion of the stack. Validation was performed with data from literature. The effect of bias voltage and key reactant probabilities on etch rate, selectivity, and profile are discussed.

Effect of Coercive Voltage and Charge Injection on Performance of a Ferroelectric-Gate Thin-Film Transistor

Directory of Open Access Journals (Sweden)

P. T. Tue

2013-01-01

Full Text Available We adopted a lanthanum oxide capping layer between semiconducting channel and insulator layers for fabrication of a ferroelectric-gate thin-film transistor memory (FGT which uses solution-processed indium-tin-oxide (ITO and lead-zirconium-titanate (PZT film as a channel layer and a gate insulator, respectively. Good transistor characteristics such as a high “on/off” current ratio, high channel mobility, and a large memory window of 108, 15.0 cm2 V−1 s−1, and 3.5 V were obtained, respectively. Further, a correlation between effective coercive voltage, charge injection effect, and FGT’s memory window was investigated. It is found that the charge injection from the channel to the insulator layer, which occurs at a high electric field, dramatically influences the memory window. The memory window’s enhancement can be explained by a dual effect of the capping layer: (1 a reduction of the charge injection and (2 an increase of effective coercive voltage dropped on the insulator.

Enhanced visible-light photocatalysis and gas sensor properties of polythiophene supported tin doped titanium nanocomposite

Science.gov (United States)

Chandra, M. Ravi; Siva Prasada Reddy, P.; Rao, T. Siva; Pammi, S. V. N.; Siva Kumar, K.; Vijay Babu, K.; Kiran Kumar, Ch.; Hemalatha, K. P. J.

2017-06-01

The polythiophene supported tin doped titanium nanocomposites (PTh/Sn-TiO2) were synthesized by modified sol-gel process through oxidative polymerization of thiophene. The fourier transform infrared spectroscopy (FT-IR) and UV-Vis diffuse reflectance spectroscopy (UV-DRS) analysis confirms the existence of synergetic interaction between metal oxide and polymer along with extension of absorption edge to visible region. The composites are found to be in spherical form with core-shell structure, which is confirmed by scanning electron spectroscopy (SEM) and transmission electron microscopy (TEM) images, the presence of all respective elements of composite are proven by energy-dispersive X-ray spectroscopy (EDX) analysis. The importance of polythiophene on surface of metal oxide has been were studied as a function of photocatalytic activity for degradation of organic pollutant congo red and gas sensor behavior towards liquid petroleum gas (LPG). All the composites are photocatalytically active and the composite with 1.5 wt% thiophene degrades the pollutant congo red within 120 min when compared to remaining catalysts under visible light irradiation. On the other hand, same composite have shown potential gas sensor properties towards LPG at 300 °C. Considering all the results, it can be noted that polythiophene acts as good sensitizer towards LPG and supporter for the tin doped titania that improve the photocatalytic activity under visible light.

Chiro-plasmonic refractory metamaterial with titanium nitride (TiN) core–shell nanohelices

Science.gov (United States)

Venkataramanababu, Sruthi; Nair, Greshma; Deshpande, Preeti; A, Jithin M.; Mohan, Sangeneni; Ghosh, Ambarish

2018-06-01

Chiral metamaterials are obtained by assembling plasmonic elements in geometries with broken mirror symmetry, which can have promising applications pertaining to generation, manipulation and detection of optical polarisation. The materials used to fabricate this promising nanosystem, especially in the visible–NIR regime, are limited to noble metals such as Au and Ag. However, they are not stable at elevated temperatures and in addition, incompatible with CMOS technologies. We demonstrate that it is possible to develop a chiro-plasmonic system based on a refractory material such as titanium nitride (TiN) which does not have these disadvantages. The building block of our metamaterial is a novel core–shell helix, obtained by coating TiN over silica nanohelices. These were arranged in a regular two-dimensional array over cm-scale areas, made possible by the use of scalable fabrication techniques such as laser interference lithography, glancing angle deposition and DC magnetron sputtering. The measured chiro-optical response was extremely broadband (1400 nm), and had contributions from individual, as well as collective plasmon modes of the interacting nanohelices, whose spectral characteristics could be easily controlled by varying the direction of the incident radiation.

Principles for prevention of toxic effects from metals

DEFF Research Database (Denmark)

Landrigan, Philip J.; Kotelchuk, David; Grandjean, Philippe

2007-01-01

of the Toxic Effects of Metals Aluminum Antimony Arsenic Barium Beryllium Bismuth Cadmium Chromium Cobalt Copper Gallium and Semiconductor Compounds Germanium Indium Iron Lead Manganese Mercury Molybdenum Nickel Palladium Platinum Selenium Silver Tellurium Thallium Tin Titanium Tungsten Uranium Vanadium Zinc...

A survey of high explosive-induced damage and spall in selected metals using proton radiography

International Nuclear Information System (INIS)

Holtkamp, D.B.; Clark, D.A.; Ferm, E.N.; Gallegos, R.A.; Hammon, D.; Hemsing, W.F.; Hogan, G.E.; Holmes, V.H.; King, N.S.P.; Lopez, R.P.; Merrill, F.E.; Morris, C.L.; Morley, K.B.; Murray, M.M.; Pazuchanics, P.D.; Prestridge, K.P.; Quintana, J.P.; Saunders, A.; Shinas, M.A.; Stacy, H.L.

2004-01-01

Multiple spall and damage layers can be created in metal when the free surface reflects a Taylor wave generated by high explosives. These phenomena have been explored in different thicknesses of several metals (tantalum, copper, 6061 T6-aluminum, and tin) using high-energy proton radiography. Multiple images (up to 21) can be produced of the dynamic evolution of damaged material on the microsecond time scale with a <50 ns 'shutter' time. Movies and multiframe still images of areal and (Abel inverted) volume densities are presented. An example of material that is likely melted on release (tin) is also presented

The role of tin-promoted Pd/MWNTs via the management of carbonaceous species in selective hydrogenation of high concentration acetylene

International Nuclear Information System (INIS)

Esmaeili, Elaheh; Mortazavi, Yadollah; Khodadadi, Abbas Ali; Rashidi, Ali Morad; Rashidzadeh, Mehdi

2012-01-01

Highlights: ► Synthesis of highly active tin-promoted catalysts by polyol method for selective hydrogenation of high concentration of acetylene. ► A positive change in the catalytic activities of tin-promoted catalysts results from distinct geometric and electronic effects. ► Change in the coverage of acetylenic overlayers for different temperature regions corresponds to the change of the number of isolated adsorption sites. ► The isolated adsorption sites are responsible for the enhancement of selectivity to ethylene with increased temperatures, via the management of the carbonaceous species over the catalyst surface. - Abstract: In the present study, Pd/MWNTs are synthesized using polyol process and modified by tin as a promoter for selective hydrogenation of high concentrated acetylene feedstock. Polyol method results in highly dispersed nanoparticles with a depletion of particle size for tin-promoted Pd catalysts as characterized by TEM. Tin promoter plays a considerable role in hydrogenation of pure acetylene stream. This is attributed to formation of Pd 2 Sn structural phase, confirmed by XRD and TPR techniques, composed mainly of intermetallic species. Catalytic behavior of tin-promoted Pd catalysts is affected by geometric and electronic factors which are more pronounced in the case of Sn/Pd = 0.25. A discontinuity in Arrhenius plots for the Sn-promoted catalysts is appeared, which seems to be due to a kinetic factor as a result of change in acetylene coverage on Pd metallic ensembles at low and high temperature ranges. Higher selectivity of the catalysts to ethylene is attributed to the presence of more isolated adsorption sites on the catalyst surface originated from both intermetallic compounds confirmed by XPS and the ones formed via the carbonaceous species upon the acetylene hydrogenation reaction.

Tribological characterization of TiN coatings prepared by magnetron sputtering

Science.gov (United States)

Makwana, Nishant S.; Chauhan, Kamlesh V.; Sonera, Akshay L.; Chauhan, Dharmesh B.; Dave, Divyeshkumar P.; Rawal, Sushant K.

2018-05-01

Titanium nitride (TiN) coating deposited on aluminium and brass pin substrates using RF reactive magnetron sputtering. The structural properties and surface morphology were characterized by X-ray diffraction (XRD), atomic force microscope (AFM) and field emission scanning electron microscope (FE-SEM). There was formation of (101) Ti2N, (110) TiN2 and (102) TiN0.30 peaks at 3.5Pa, 2Pa and 1.25Pa sputtering pressure respectively. The tribological properties of coating were inspected using pin on disc tribometer equipment. It was observed that TiN coated aluminium and brass pins demonstrated improved wear resistance than uncoated aluminium and brass pins.

Surface segregation energies in transition-metal alloys

DEFF Research Database (Denmark)

Ruban, Andrei; Skriver, Hans Lomholt; Nørskov, Jens Kehlet

1999-01-01

We present a database of 24 x 24 surface segregation energies of single transition metal impurities in transition-metal hosts obtained by a Green's-function linear-muffin-tin-orbitals method in conjunction with the coherent potential and atomic sphere approximations including a multipole correction...... to the electrostatic potential and energy. We use the database to establish the major factors which govern surface segregation in transition metal alloys. We find that the calculated trends are well described by Friedel's rectangular state density model and that the few but significant deviations from the simple...

Simulations of interference effects in gated two-dimensional ballistic electron systems

DEFF Research Database (Denmark)

Jauho, Antti-Pekka; Pichugin, K.N.; Sadreev, A.F.

1999-01-01

We present detailed simulations addressing recent electronic interference experiments,where a metallic gate is used to locally modify the Fermi wavelength of the charge carriers. Our numerical calculations are based on a solution of the one-particle Schrodinger equation for a realistic model of t...

NiCo_2O_4@TiN Core-shell Electrodes through Conformal Atomic Layer Deposition for All-solid-state Supercapacitors

International Nuclear Information System (INIS)

Wang, Ruiqi; Xia, Chuan; Wei, Nini; Alshareef, Husam N.

2016-01-01

Highlights: • NiCo_2O_4 nanostructures are prepared via a simple hydrothermal method. • Outer shell of TiN is then grown through conformal atomic layer deposition. • Electrodes exhibit significantly enhanced rate capability with TiN coating. • Solid-state polymer electrolyte is employed to improve cycling stability. • Full devices show a stack power density of 58.205 mW cm"−"3 at 0.061 mWh cm"−"3. - Abstract: Ternary transition metal oxides such as NiCo_2O_4 show great potential as supercapacitor electrode materials. However, the unsatisfactory rate performance of NiCo_2O_4 may prove to be a major hurdle to its commercial usage. Herein, we report the development of NiCo_2O_4@TiN core–shell nanostructures for all-solid-state supercapacitors with significantly enhanced rate capability. We demonstrate that a thin layer of TiN conformally grown by atomic layer deposition (ALD) on NiCo_2O_4 nanofiber arrays plays a key role in improving their electrical conductivity, mechanical stability, and rate performance. Fabricated using the hybrid NiCo_2O_4@TiN electrodes, the symmetric all-solid-state supercapacitor exhibited an impressive stack power density of 58.205 mW cm"−"3 at a stack energy density of 0.061 mWh cm"−"3. To the best of our knowledge, these values are the highest of any NiCo_2O_4-based all-solid-state supercapacitor reported. Additionally, the resulting NiCo_2O_4@TiN all-solid-state device displayed outstanding cycling stability by retaining 70% of its original capacitance after 20,000 cycles at a high current density of 10 mA cm"−"2. These results illustrate the promise of ALD-assisted hybrid NiCo_2O_4@TiN electrodes within sustainable and integrated energy storage applications.

Tin and tin-titanium as catalyst components for reversible hydrogen storage of sodium aluminium hydride

Energy Technology Data Exchange (ETDEWEB)

Qi Jia Fu; Shik Chi Tsang [University of Reading, Reading (United Kingdom). Surface and Catalysis Research Centre, School of Chemistry

2006-10-15

This paper is concerned with the effects of adding tin and/or titanium dopant to sodium aluminium hydride for both dehydrogenation and re-hydrogenation reactions during their reversible storage of molecular hydrogen. Temperature programmed decomposition (TPD) measurements show that the dehydrogenation kinetics of NaAlH{sub 4} are significantly enhanced upon doping the material with 2 mol% of tributyltin hydride, Sn(Bu)3H but the tin catalyst dopant is shown to be inferior than titanium. On the other hand, in this preliminary work, a significant synergetic catalytic effect is clearly revealed in material co-doped with both titanium and tin catalysts which shows the highest reversible rates of dehydrogenation and re-hydrogenation (after their hydrogen depletion). The re-hydrogenation rates of depleted Sn/Ti/NaAlH{sub 4} evaluated at both 9.5 and 140 bars hydrogen are also found to be favourable compared to the Ti/NaAlH{sub 4}, which clearly suggest the importance of the catalyst choice. Basing on these results some mechanistic insights for the catalytic reversible dehydrogenation and re-hydrogenation processes of Sn/Ti/NaAlH{sub 4} are therefore made. 31 refs., 8 figs., 2 tabs.

Transferred metal electrode films for large-area electronic devices

International Nuclear Information System (INIS)

Yang, Jin-Guo; Kam, Fong-Yu; Chua, Lay-Lay

2014-01-01

The evaporation of metal-film gate electrodes for top-gate organic field-effect transistors (OFETs) limits the minimum thickness of the polymer gate dielectric to typically more than 300 nm due to deep hot metal atom penetration and damage of the dielectric. We show here that the self-release layer transfer method recently developed for high-quality graphene transfer is also capable of giving high-quality metal thin-film transfers to produce high-performance capacitors and OFETs with superior dielectric breakdown strength even for ultrathin polymer dielectric films. Dielectric breakdown strengths up to 5–6 MV cm −1 have been obtained for 50-nm thin films of polystyrene and a cyclic olefin copolymer TOPAS ® (Zeon). High-quality OFETs with sub-10 V operational voltages have been obtained this way using conventional polymer dielectrics and a high-mobility polymer semiconductor poly[2,5-bis(3-tetradecylthiophene-2-yl)thieno[3,2-b]thiophene-2,5-diyl]. The transferred metal films can make reliable contacts without damaging ultrathin polymer films, self-assembled monolayers and graphene, which is not otherwise possible from evaporated or sputtered metal films

Microstructure and chemical analysis of Hf-based high-k dielectric layers in metal-insulator-metal capacitors

Energy Technology Data Exchange (ETDEWEB)

Thangadurai, P. [Department of Materials Engineering, Technion - Israel Institute of Technology, Haifa 32000 (Israel); Mikhelashvili, V.; Eisenstein, G. [Department of Electrical Engineering, Technion - Israel Institute of Technology, Haifa 32000 (Israel); Kaplan, W.D., E-mail: kaplan@tx.technion.ac.i [Department of Materials Engineering, Technion - Israel Institute of Technology, Haifa 32000 (Israel)

2010-05-31

The microstructure and chemistry of the high-k gate dielectric significantly influences the performance of metal-insulator-metal (MIM) and metal-oxide-semiconductor devices. In particular, the local structure, chemistry, and inter-layer mixing are important phenomena to be understood. In the present study, high resolution and analytical transmission electron microscopy are combined to study the local structure, morphology, and chemistry in MIM capacitors containing a Hf-based high-k dielectric. The gate dielectric, bottom and gate electrodes were deposited on p-type Si(100) wafers by electron beam evaporation. Four chemically distinguishable sub-layers were identified within the dielectric stack. One is an unintentionally formed 4.0 nm thick interfacial layer of Ta{sub 2}O{sub 5} at the interface between the Ta electrode and the dielectric. The other three layers are based on HfN{sub x}O{sub y} and HfTiO{sub y}, and intermixing between the nearby sub-layers including deposited SiO{sub 2}. Hf-rich clusters were found in the HfN{sub x}O{sub y} layer adjacent to the Ta{sub 2}O{sub 5} layer.

Water-gel for gating graphene transistors.

Science.gov (United States)

Kim, Beom Joon; Um, Soong Ho; Song, Woo Chul; Kim, Yong Ho; Kang, Moon Sung; Cho, Jeong Ho

2014-05-14

Water, the primary electrolyte in biology, attracts significant interest as an electrolyte-type dielectric material for transistors compatible with biological systems. Unfortunately, the fluidic nature and low ionic conductivity of water prevents its practical usage in such applications. Here, we describe the development of a solid state, megahertz-operating, water-based gate dielectric system for operating graphene transistors. The new electrolyte systems were prepared by dissolving metal-substituted DNA polyelectrolytes into water. The addition of these biocompatible polyelectrolytes induced hydrogelation to provide solid-state integrity to the system. They also enhanced the ionic conductivities of the electrolytes, which in turn led to the quick formation of an electric double layer at the graphene/electrolyte interface that is beneficial for modulating currents in graphene transistors at high frequencies. At the optimized conditions, the Na-DNA water-gel-gated flexible transistors and inverters were operated at frequencies above 1 MHz and 100 kHz, respectively.

Suspended graphene devices with local gate control on an insulating substrate

International Nuclear Information System (INIS)

Ong, Florian R; Cui, Zheng; Vojvodin, Cameron; Papaj, Michał; Deng, Chunqing; Bal, Mustafa; Lupascu, Adrian; Yurtalan, Muhammet A; Orgiazzi, Jean-Luc F X

2015-01-01

We present a fabrication process for graphene-based devices where a graphene monolayer is suspended above a local metallic gate placed in a trench. As an example we detail the fabrication steps of a graphene field-effect transistor. The devices are built on a bare high-resistivity silicon substrate. At temperatures of 77 K and below, we observe the field-effect modulation of the graphene resistivity by a voltage applied to the gate. This fabrication approach enables new experiments involving graphene-based superconducting qubits and nano-electromechanical resonators. The method is applicable to other two-dimensional materials. (paper)

One-electron theory of metals

International Nuclear Information System (INIS)

Skriver, H.L.

1984-12-01

The work described in the report and the 16 accompanying publications is based upon a one-electron theory obtained within the local approximation to density-functional theory, and deals with the ground state of metals as obtained from self-consistent electronic-structure calculations performed by means of the Linear Muffin-Tin Orbital (LMTO) method. It has been the goal of the work to establish how well this one-electron approach describes physical properties such as the crystal structures of the transition metals, the structural phase transitions in the alkali, alkaline earth, and rare earth metals, and the localization of 3d, 4f, and 5f electrons in the 3d metal monoxides, the light lanthanides, and the actinides, respectively, as well as the cohesive properties of metals in general. (orig.)

Ab initio work function of elemental metals

DEFF Research Database (Denmark)

Skriver, Hans Lomholt; Rosengaard, N. M.

1992-01-01

We have used a recently developed self-consistent Green’s-function technique based on tight-binding linear-muffin-tin-orbital theory to calculate the work function for the close-packed surfaces of 37 elemental metals. The results agree with the limited experimental data obtained from single cryst...

Silicon dioxide with a silicon interfacial layer as an insulating gate for highly stable indium phosphide metal-insulator-semiconductor field effect transistors

Science.gov (United States)

Kapoor, V. J.; Shokrani, M.

1991-01-01

A novel gate insulator consisting of silicon dioxide (SiO2) with a thin silicon (Si) interfacial layer has been investigated for high-power microwave indium phosphide (InP) metal-insulator-semiconductor field effect transistors (MISFETs). The role of the silicon interfacial layer on the chemical nature of the SiO2/Si/InP interface was studied by high-resolution X-ray photoelectron spectroscopy. The results indicated that the silicon interfacial layer reacted with the native oxide at the InP surface, thus producing silicon dioxide, while reducing the native oxide which has been shown to be responsible for the instabilities in InP MISFETs. While a 1.2-V hysteresis was present in the capacitance-voltage (C-V) curve of the MIS capacitors with silicon dioxide, less than 0.1 V hysteresis was observed in the C-V curve of the capacitors with the silicon interfacial layer incorporated in the insulator. InP MISFETs fabricated with the silicon dioxide in combination with the silicon interfacial layer exhibited excellent stability with drain current drift of less than 3 percent in 10,000 sec, as compared to 15-18 percent drift in 10,000 sec for devices without the silicon interfacial layer. High-power microwave InP MISFETs with Si/SiO2 gate insulators resulted in an output power density of 1.75 W/mm gate width at 9.7 GHz, with an associated power gain of 2.5 dB and 24 percent power added efficiency.

Seasonal study on Bothriocephalus as indicator of metal pollution in ...

African Journals Online (AJOL)

Seasonal study on Bothriocephalus as indicator of metal pollution in yellowfish, ... Water and sediment, as well as liver, muscle and tapeworm samples were ... iron, cobalt, nickel, copper, zinc, arsenic, selenium, molybdenum, cadmium, tin, ...

Lithium alloys and metal oxides as high-capacity anode materials for lithium-ion batteries

International Nuclear Information System (INIS)

Liang, Chu; Gao, Mingxia; Pan, Hongge; Liu, Yongfeng; Yan, Mi

2013-01-01

Highlights: •Progress in lithium alloys and metal oxides as anode materials for lithium-ion batteries is reviewed. •Electrochemical characteristics and lithium storage mechanisms of lithium alloys and metal oxides are summarized. •Strategies for improving electrochemical lithium storage properties of lithium alloys and metal oxides are discussed. •Challenges in developing lithium alloys and metal oxides as commercial anodes for lithium-ion batteries are pointed out. -- Abstract: Lithium alloys and metal oxides have been widely recognized as the next-generation anode materials for lithium-ion batteries with high energy density and high power density. A variety of lithium alloys and metal oxides have been explored as alternatives to the commercial carbonaceous anodes. The electrochemical characteristics of silicon, tin, tin oxide, iron oxides, cobalt oxides, copper oxides, and so on are systematically summarized. In this review, it is not the scope to retrace the overall studies, but rather to highlight the electrochemical performances, the lithium storage mechanism and the strategies in improving the electrochemical properties of lithium alloys and metal oxides. The challenges and new directions in developing lithium alloys and metal oxides as commercial anodes for the next-generation lithium-ion batteries are also discussed

Electrodeposition, characterization and corrosion investigations of galvanic tin-zinc layers from pyrophosphate baths

OpenAIRE

STOPIC MILENA D.; FRIEDRICH BERND G.

2016-01-01

Tin-zinc alloy deposits are recognized as a potential alternative to toxic cadmium as corrosion resistant coatings. Tin-zinc alloy layers offer outstanding corrosion protection for steel by combining the barrier protection of tin with the galvanic protection of zinc. Tin-zinc coatings have been used on the chassis of electrical and electronic apparatus and on critical automotive parts such as fuel and brake line components. In this study, tin-zinc alloy deposits were successfully prepared fro...

Determination of tin in cassiterite ores by colorimetry of iodometry

International Nuclear Information System (INIS)

Rodriguez Hernandez, B.

1972-01-01

The analytical methods are described far the determination of tin in cassiterite ores. The gallein-colorimetric method is described for determining small amounts of tin, covering the 0,01-0,5 per cent range. The sample is decomposed by heating with ammonium iodide, and tin is analyzed colorimetrically by means of it s complex with gallein. The final measure may be brought about either visually or spectrophotometrically at 525 nm. (Author)

Durability of metals from archaeological objects, metal meteorites, and native metals

International Nuclear Information System (INIS)

Johnson, A.B. Jr.; Francis, B.

1980-01-01

Metal durability is an important consideration in the multi-barrier nuclear waste storage concept. This study summarizes the ancient metals, the environments, and factors which appear to have contributed to metal longevity. Archaeological and radiochemical dating suggest that human use of metals began in the period 6000 to 7000 BC. Gold is clearly the most durable, but many objects fashioned from silver, copper, bronze, iron, lead, and tin have survived for several thousand years. Dry environments, such as tombs, appear to be optimum for metal preservation, but some metals have survived in shipwrecks for over a thousand years. The metal meteorites are Fe-base alloys with 5 to 60 wt% Ni and minor amounts of Co, I, and S. Some meteoritic masses with ages estimated to be 5,000 to 20,000 years have weathered very little, while other masses from the same meteorites are in advanced stages of weathering. Native metals are natural metallic ores. Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion. Dry cooling tower technology has demonstrated that in pollution-free moist environments, metals fare better at temperatures above than below the dewpoint. Thus, in moderate temperature regimes, elevated temperatures may be useful rather than detrimental for exposures of metal to air. In liquid environments, relatively complex radiolysis reactions can occur, particularly where multiple species are present. A dry environment largely obviates radiolysis effects

Durability of metals from archaeological objects, metal meteorites, and native metals

Energy Technology Data Exchange (ETDEWEB)

Johnson, A.B. Jr.; Francis, B.

1980-01-01

Metal durability is an important consideration in the multi-barrier nuclear waste storage concept. This study summarizes the ancient metals, the environments, and factors which appear to have contributed to metal longevity. Archaeological and radiochemical dating suggest that human use of metals began in the period 6000 to 7000 BC. Gold is clearly the most durable, but many objects fashioned from silver, copper, bronze, iron, lead, and tin have survived for several thousand years. Dry environments, such as tombs, appear to be optimum for metal preservation, but some metals have survived in shipwrecks for over a thousand years. The metal meteorites are Fe-base alloys with 5 to 60 wt% Ni and minor amounts of Co, I, and S. Some meteoritic masses with ages estimated to be 5,000 to 20,000 years have weathered very little, while other masses from the same meteorites are in advanced stages of weathering. Native metals are natural metallic ores. Approximately five million tonnes were mined from native copper deposits in Michigan. Copper masses from the Michigan deposits were transported by the Pleistocene glaciers. Areas on the copper surfaces which appear to represent glacial abrasion show minimal corrosion. Dry cooling tower technology has demonstrated that in pollution-free moist environments, metals fare better at temperatures above than below the dewpoint. Thus, in moderate temperature regimes, elevated temperatures may be useful rather than detrimental for exposures of metal to air. In liquid environments, relatively complex radiolysis reactions can occur, particularly where multiple species are present. A dry environment largely obviates radiolysis effects.

Correlation between the structure and optical transition characteristic energies of annealed tin oxide films

International Nuclear Information System (INIS)

Majid, W.H.A.; Muhamad, M.R.

1990-01-01

Thin films of tin oxide were prepared by room temperature thermal evaporation of blue-black stannous-oxide, SnO powder synthesized from metal tin. X-ray diffractograms reveal that as prepared amorphous samples form polycrystal of SnO by annealing at 300 0 C in air ambient for 30 minutes and they will be oxidized to polycrystal of SnO 2 with further annealing at 500 0 C or above. Optical measurements indicate that the dispersion energy E d and the single oscillator strength E 0 are highest for SnO polycrystal with a magnitude for about 14.0 eV and 4.0 eV respectively compared to 10.4 eV and 3.4 eV for SnO 2 . Further, the plasma energy E p was determined to be in the range of 3.4 eV to 8 eV; increases with increasing composition of SnO 2 . The density of valence electron N(E) can be estimated from the plasma energy E p

Effects of process parameters on sheet resistance uniformity of fluorine-doped tin oxide thin films

Science.gov (United States)

Hudaya, Chairul; Park, Ji Hun; Lee, Joong Kee

2012-01-01

An alternative indium-free material for transparent conducting oxides of fluorine-doped tin oxide [FTO] thin films deposited on polyethylene terephthalate [PET] was prepared by electron cyclotron resonance - metal organic chemical vapor deposition [ECR-MOCVD]. One of the essential issues regarding metal oxide film deposition is the sheet resistance uniformity of the film. Variations in process parameters, in this case, working and bubbler pressures of ECR-MOCVD, can lead to a change in resistance uniformity. Both the optical transmittance and electrical resistance uniformity of FTO film-coated PET were investigated. The result shows that sheet resistance uniformity and the transmittance of the film are affected significantly by the changes in bubbler pressure but are less influenced by the working pressure of the ECR-MOCVD system.

Upgrading tantalum and niobium oxides content in Bangka tin slag with double leaching

Science.gov (United States)

Soedarsono, J. W.; Permana, S.; Hutauruk, J. K.; Adhyputra, R.; Rustandi, A.; Maksum, A.; Widana, K. S.; Trinopiawan, K.; Anggraini, M.

2018-03-01

Tantalum has become one of the 14 types of critical materials where the level of its availability is assumed as the midterm critical metal. Benefits of the element tantalum in the electronics field increased the deficit balance of supply / demand, as more variations of electronic products developed. The tantalum experts calculated the level of availability until 2020. Base on the previous studies, tin slag is a secondary source of tantalum and niobium. This study uses tin slag from Bangka, Indonesia, abbreviated, Bangka Tin Slag (BTS). BTS was roasted, water quenched and sieved, abbreviated BTS-RQS.BTS was roasted, water quenched and sieved, abbreviated BTS-RQS.BTS-RQS was roasted at a temperature 700□C given sample code BTS-R700QS, while roasted at 800°C given sample code BTS-R800QS.A variable leaching experiment on BTS-R700QS was solvent concentration variable and on BTS-R800QS was time variable. The entire residue was characterized by X-Ray Fluorescence (XRF), and the optimum results are on the BTS-R800QS leaching into 5 M NaOH for 20 min followed by 5M HCl for 50 min, with content of Ta2O5 and Nb2O51.56% and 1.11%, respectively. The result of XRF measurement showed was the increasing of TNO content due to the increasing solvent concentration and time of acid leaching. The discussion of thermodynamics this study used was HSC Chemistry 6 as a supporting data.

Tunneling Conductance in Two-Dimensional Junctions between a Normal Metal and a Ferromagnetic Rashba Metal

Science.gov (United States)

Oshima, Daisuke; Taguchi, Katsuhisa; Tanaka, Yukio

2018-03-01

We have studied charge transport in a ferromagnetic Rashba metal (FRM), where both Rashba type spin-orbit coupling (RSOC) and exchange coupling coexist. It has nontrivial metallic states, i.e., a normal Rashba metal (NRM), anomalous Rashba metal (ARM), and Rashba ring metal (RRM), and they are manipulated by tuning the Fermi level with an applied gate voltage. We theoretically studied the tunneling conductance (G) in a normal metal/FRM junction by changing the Fermi level via an applied gate voltage (Vg) on the FRM. We found a wide variation in the Vg dependence of G, which depends on the metallic states. In an NRM, the Vg dependence of G is the same as that in a conventional two-dimensional system. However, in an ARM, the Vg dependence of G is similar to that in a conventional one- (two-)dimensional system for a large (small) RSOC. Furthermore, in an RRM, which is generated by a large RSOC, the Vg dependence of G is similar to that in the one-dimensional system. In addition, these anomalous properties stem from the density of states in the ARM and RRM caused by the large RSOC and exchange coupling rather than the spin-momentum locking of RSOC.

Conducting tin halides with a layered organic-based perovskite structure

Science.gov (United States)

Mitzi, D. B.; Feild, C. A.; Harrison, W. T. A.; Guloy, A. M.

1994-06-01

THE discovery1 of high-temperature superconductivity in layered copper oxide perovskites has generated considerable fundamental and technological interest in this class of materials. Only a few other examples of conducting layered perovskites are known; these are also oxides such as (La1-xSrx)n+1 MnnO3n+1 (ref. 2), Lan+1NinO3n+1 (ref. 3) and Ban+1PbnO3n+1 (ref. 4), all of which exhibit a trend from semiconducting to metallic behaviour with increasing number of perovskite layers (n). We report here the synthesis of a family of organic-based layered halide perovskites, (C4H9NH3)2(CH3NH3)n-1Snnl3n+1 which show a similar transition from semiconducting to metallic behaviour with increasing n. The incorporation of an organic modulation layer between the conducting tin iodide sheets potentially provides greater flexibility for tuning the electrical properties of the perovskite sheets, and we suggest that such an approach will prove valuable for exploring the range of transport properties possible with layered perovskites.

Ultrasmall Tin Nanodots Embedded in Nitrogen-Doped Mesoporous Carbon: Metal-Organic-Framework Derivation and Electrochemical Application as Highly Stable Anode for Lithium Ion Batteries

International Nuclear Information System (INIS)

Dai, Ruoling; Sun, Weiwei; Wang, Yong

2016-01-01

Highlights: • Sn-based metal-organic-framework (MOF) is prepared. • Ultrasmall tin nanodots (2–3 nm) are embedded in nitrogen-doped mesoporous carbon. • The Sn/C composite anode shows high capacity and ultralong cycle life. - Abstract: This work reports a facile metal-organic-framework based approach to synthesize Sn/C composite, in which ultrasmall Sn nanodots with typical size of 2–3 nm are uniformly embedded in the nitrogen-doped porous carbon matrix (denoted as Sn@NPC). The effect of thermal treatment and nitrogen doping are also explored. Owing to the delicate size control and confined volume change within carbon matrix, the Sn@NPC composite can exhibit reversible capacities of 575 mAh g −1 (Sn contribution: 1091 mAh g −1 ) after 500 cycles at 0.2 A g −1 and 507 mAh g −1 (Sn contribution: 1077 mAh g −1 ) after 1500 cycles at 1 A g −1 . The excellent long-life electrochemical stability of the Sn@NPC anode has been mainly attributed to the uniform distribution of ultrasmall Sn nanodots and the highly-conductive and flexible N-doped carbon matrix, which can effectively facilitate lithium ion/electron diffusion, buffer the large volume change and improve the structure stability of the electrode during repetitive cycling with lithium ions.

Studies on tin based inorganic ion exchangers for fission products separation

International Nuclear Information System (INIS)

Dash, A.; Balasubramanian, K.R.; Murthy, T.S.

1993-01-01

Tin(IV) antimonate and hydrous tin(IV) oxide have been prepared and their characteristics are evaluated. A new method has been finalized for the separation of 95 Zr- 95 Nb from irradiated uranium using hydrous tin(IV) oxide. In this process, the irradiated sample is dissolved in concentrated HNO 3 , evaporated to near dryness and taken up in 0.5 M HNO 3 . The solution is passed over tin(IV) oxide column and the isotope eluted with 10 M HNO 3 . The product is obtained in pure nitrate form which is generally preferred for different applications. A method has been finalized for the separation of 106 Ru from fission product solution using tin(IV) antimonate. In this method fission product solution is adjusted to 2 M with respect to nitric acid, 137 Cs is separated on a column of ammonium phosphomolybdate, the effluent after adjustment of acidity to 0.2 M is then passed over a column of tin(IV) antimonate where the effluent contains pure 106 Ru. (author). 14 refs., 6 figs., 2 tabs

Growth of Ag micro/nanoparticles using stress migration from multilayered metallic structure

International Nuclear Information System (INIS)

Lu, Yebo; Li, Yuan; Saka, Masumi

2015-01-01

Highlights: • A multilayered metallic structure was proposed to fabricate Ag micro/nanoparticles via stress migration. • Both ductile Pt and brittle TiN films can be used as the passivation layer by providing pathways for atomic migration. • The diameter of the formed Ag particle can be controlled using different material for passivation layer and changing the heating temperature. - Abstract: A multilayered metallic structure, consisting of Cu foil and subsequently deposited Ag thin film covered with a passivation layer, was proposed to fabricate Ag micro/nanoparticles by stress migration. With employing a ductile Pt or brittle TiN thin film as passivation, Ag micro/nanoparticles were successfully fabricated by annealing the corresponding multilayered structure. The relationship between characteristics (average diameter, number and volume) of the formed Ag micro/nanoparticles and the annealing temperature was discussed. On this basis, the growth mechanism was developed, which indicates that the dimension of Ag particles was mainly dominated by the different pathways for the migration of diffused Ag atoms in the passivation layers of Pt and TiN and the annealing temperature

Optical absorption, {sup 31}P NMR, and photoluminescence spectroscopy study of copper and tin co-doped barium–phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Jiménez, J.A., E-mail: jose.jimenez@unf.edu; Zhao, C.

2014-10-15

The optical and structural properties of 50P{sub 2}O{sub 5}:50BaO glasses prepared by melting have been investigated for additive concentrations of 10 and 1 mol% of CuO and SnO dopants. Absorption and photoluminescence spectroscopies were employed in the optical characterization, whereas structural properties were assessed by {sup 31}P nuclear magnetic resonance (NMR) spectroscopy. Residual Cu{sup 2+} was detectable by absorption spectroscopy for the highest concentration of CuO and SnO. More prominently, the optical data suggests contributions from both twofold-coordinated Sn centers and Cu{sup +} ions to light absorption and emission in the glasses. The luminescence depends strongly on excitation wavelength for the highest concentration of dopants where a blue–white emission is observed under short-wavelength excitation (e.g., 260 nm) largely due to tin, while an orange luminescence is exhibited for longer excitation wavelengths (e.g., 360 nm) essentially due to Cu{sup +} ions. On the other hand, dissimilar luminescent properties were observed in connection to Cu{sup +} ions for the lowest concentration studied, as the copper ions were preferentially excited in a narrower range at shorter wavelengths near tin centers absorption. The structural analyses revealed the glass matrix to be composed essentially of Q{sup 2} (two bridging oxygens) and Q{sup 1} (one bridging oxygen) phosphate tetrahedra. A slight increase in the Q{sup 1}/Q{sup 2} ratio reflected upon SnO doping alone suggests a major incorporation of tin into the glass network via P–O–Sn bonds, compatible with the 2-coordinated state attributed to the luminescent Sn centers. However, a significant increase in the Q{sup 1}/Q{sup 2} ratio was indicated with the incorporation of copper at the highest concentration, consistent with a key role of the metal ions as network modifiers. Thus, the change in Cu{sup +} optical properties concurs with different distributions of local environments around the

Characterization of 0.18- μm gate length AlGaN/GaN HEMTs on SiC fabricated using two-step gate recessing

Science.gov (United States)

Yoon, Hyung Sup; Min, Byoung-Gue; Lee, Jong Min; Kang, Dong Min; Ahn, Ho Kyun; Cho, Kyu-Jun; Do, Jae-Won; Shin, Min Jeong; Jung, Hyun-Wook; Kim, Sung Il; Kim, Hae Cheon; Lim, Jong Won

2017-09-01

We fabricated a 0.18- μm gate-length AlGaN/GaN high electron mobility transistor (HEMT) on SiC substrate fabricated by using two-step gate recessing which was composed of inductively coupled plasma (ICP) dry etching with a gas mixture of BCl3/Cl2 and wet chemical etching using the oxygen plasma treatment and HCl-based cleaning. The two-step gate recessing process exhibited an etch depth of 4.5 nm for the AlGaN layer and the clean surface of AlGaN layer at the AlGaN/gate metal contact region for the AlGaN/GaN HEMT structure. The recessed 0.18 μm × 200 μm AlGaN/GaN HEMT devices showed good DC characteristics, having a good Schottky diode ideality factor of 1.25, an extrinsic transconductance ( g m ) of 345 mS/mm, and a threshold voltage ( V th ) of -2.03 V. The recessed HEMT devices exhibited high RF performance, having a cut-off frequency ( f T ) of 48 GHz and a maximum oscillation frequency ( f max ) of 130 GHz. These devices also showed minimum noise figure of 0.83 dB and associated gain of 12.2 dB at 10 GHz.

Tin electrodeposition from sulfate solution containing a benzimidazolone derivative

Directory of Open Access Journals (Sweden)

Said BAKKALI

2016-11-01

Full Text Available Tin electrodeposition in an acidic medium in the presence of N,N’-1,3-bis-[N-3-(6-deoxy-3-O-methyl-D-glucopyranose-6-yl-2-oxobenzimidazol-1-yl]-2-tetradecyloxypropane as an additive was investigated in this work. The adequate current density and the appropriate additive concentration were determined by gravimetric measurements. Chronopotentiometric curves showed that the presence of the additive caused an increase in the overpotential of tin reduction. The investigations by cyclic voltammetry technique revealed that, in the presence and in absence of the additive, there were two peaks, one in the cathodic side attributed to the reduction of Sn2+ and the other one in the anodic side assigned to the oxidation of tin previously formed during the cathodic scan. The surface morphology of the tin deposits was studied by scanning electron microscopy (SEM and XRD.

Preparation, composition, and solid state investigations of TiN, ZrN, NbN, and compounds from the pseudobinary systems NbN-NbC, NbN-TiC, and NbN-TiN

International Nuclear Information System (INIS)

Christensen, A.N.; Fregerslev, S.

1977-01-01

Single crystals of the cubic phases TiN, ZrN, delta-NbN and of compounds from the pseudobinary systems NbN-NbC, NbN-TiC, and NbN-TiN were obtained by zone melting, zone annealing and annealing of the metal carbides in nitrogen gas of 2 MPa. Single crystals of the tetragonal phase gamma-NbN were obtained in a similar way by annealing of niobium. The nitrides are non-stochiometric. TiN was obtained in the composition range TiNsub(0.99) to TiNsub(0.50), ZrN in the range ZrNsub(1.00) to ZrNsub(0.63), and in niobium nitrides were obtained in the composition range NbNsub(0.90) to NbNsub(0.69). The compounds from the pseudobinary systems have up to 35% vacant sites in the nitrogen-carbon sublattice. TiN and ZrN have only vacant sites in the nitrogen sublattice. A correlation is found between the unit cell parameters for titanium nitride and zirconium nitride and the nitrogen-metal ratios. (orig.) [de

Indium Tin Oxide thin film gas sensors for detection of ethanol vapours

International Nuclear Information System (INIS)

Vaishnav, V.S.; Patel, P.D.; Patel, N.G.

2005-01-01

Indium Tin Oxide (ITO: In 2 O 3 + 17% SnO 2 ) thin films grown on alumina substrate at 648 K temperatures using direct evaporation method with two gold pads deposited on the top for electrical contacts were exposed to ethanol vapours (200-2500 ppm). The operating temperature of the sensor was optimized. The sensitivity variation of films having different thickness was studied. The sensitivity of the films deposited on Si substrates was studied. The response of the film with MgO catalytic layer on sensitivity and selectivity was observed. A novel approach of depositing thin stimulating layer of various metals/oxides below the ITO film was tried and tested

The Moessbauer effect in binary tin chalcogenides of tin 119

International Nuclear Information System (INIS)

Ortalli, I.; Fano, V.

1975-01-01

The values of the isomer shift, quadrupole splitting, Moessbauer coefficient, Debye temperature for the tin chalcogenides SnS. SnSe, SnTe are tabulated for the temperatures 80 and 300 K. Temperature dependences of the Moessbauer coefficient and of the effective Debye temperature for SnS, SnSe and SnTe in a temperature range of 78 to 300 K are presented. (Z.S.)

P-channel differential multiple-time programmable memory cells by laterally coupled floating metal gate fin field-effect transistors

Science.gov (United States)

Wang, Tai-Min; Chien, Wei-Yu; Hsu, Chia-Ling; Lin, Chrong Jung; King, Ya-Chin

2018-04-01

In this paper, we present a new differential p-channel multiple-time programmable (MTP) memory cell that is fully compatible with advanced 16 nm CMOS fin field-effect transistors (FinFET) logic processes. This differential MTP cell stores complementary data in floating gates coupled by a slot contact structure, which make different read currents possible on a single cell. In nanoscale CMOS FinFET logic processes, the gate dielectric layer becomes too thin to retain charges inside floating gates for nonvolatile data storage. By using a differential architecture, the sensing window of the cell can be extended and maintained by an advanced blanket boost scheme. The charge retention problem in floating gate cells can be improved by periodic restoring lost charges when significant read window narrowing occurs. In addition to high programming efficiency, this p-channel MTP cells also exhibit good cycling endurance as well as disturbance immunity. The blanket boost scheme can remedy the charge loss problem under thin gate dielectrics.

Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

Science.gov (United States)

Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

2010-01-01

To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish .