Biopolymer nanostructures induced by plasma irradiation and metal sputtering

Energy Technology Data Exchange (ETDEWEB)

Slepička, P., E-mail: petr.slepicka@vscht.cz [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Juřík, P. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic); Malinský, P.; Macková, A. [Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Rez, Prague 25068 (Czech Republic); Faculty of Science, J.E. Purkyně University, Ústí nad Labem (Czech Republic); Kasálková, N. Slepičková; Švorčík, V. [Department of Solid State Engineering, Institute of Chemical Technology, 166 28 Prague (Czech Republic)

2014-08-01

Modification based on polymer surface exposure to plasma treatment exhibits an easy and cheap technique for polymer surface nanostructuring. The influence of argon plasma treatment on biopolymer poly(L-lactide acid (PLLA) will be presented in this paper. The combination of Ar{sup +} ion irradiation, consequent sputter metallization (platinum) and thermal annealing of polymer surface will be summarized. The surface morphology was studied using atomic force microscopy. The Rutherford Backscattering Spectroscopy and X-ray Photoelectron Spectroscopy were used as analytical methods. The combination of plasma treatment with consequent thermal annealing and/or metal sputtering led to the change of surface morphology and its elemental ratio. The surface roughness and composition has been strongly influenced by the modification parameters and metal layer thickness. By plasma treatment of polymer surface combined with consequent annealing or metal deposition can be prepared materials applicable both in tissue engineering as cell carriers, but also in integrated circuit manufacturing.

The sputtering of the deformed gold under irradiation with krypton swift heavy ions

International Nuclear Information System (INIS)

Didyk, A.Yu.; Semina, V.K.; Hofman, A.

2002-01-01

The results about sputtering yield of gold irradiated by 86 Kr ions with high inelastic energy losses up to a fluence of 10 14 ion/cm 2 are presented. It was shown that the sputtering (evaporation) yield strongly depends on the initial defect concentration in gold. The sputtering yield begins to grow very strongly with the increasing of damage created by heavy ion elastic and inelastic energy losses. The temperature on the surface in the area around krypton ion trajectory is much higher than the melting and evaporation temperatures for gold as follows from calculations with the various expressions and models

Charge-state related effects in sputtering of LiF by swift heavy ions

Energy Technology Data Exchange (ETDEWEB)

Assmann, W. [Ludwig-Maximilians-Universität München, 85748 Garching (Germany); Ban-d' Etat, B. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Bender, M. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Boduch, P. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Grande, P.L. [Univ. Fed. Rio Grande do Sul, BR-91501970 Porto Alegre, RS (Brazil); Lebius, H.; Lelièvre, D. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Marmitt, G.G. [Univ. Fed. Rio Grande do Sul, BR-91501970 Porto Alegre, RS (Brazil); Rothard, H. [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Seidl, T.; Severin, D.; Voss, K.-O. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Toulemonde, M., E-mail: toulemonde@ganil.fr [Centre de Recherche sur les Ions, les Matériaux et la photonique, CIMAP-GANIL, CEA–CNRS–ENSICAEN–Univ. Caen, 14070 Caen (France); Trautmann, C. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Technische Universität Darmstadt, 64289 Darmstadt (Germany)

2017-02-01

Sputtering experiments with swift heavy ions in the electronic energy loss regime were performed by using the catcher technique in combination with elastic recoil detection analysis. The angular distribution of particles sputtered from the surface of LiF single crystals is composed of a jet-like peak superimposed on a broad isotropic distribution. By using incident ions of fixed energy but different charges states, the influence of the electronic energy loss on both components is probed. We find indications that isotropic sputtering originates from near-surface layers, whereas the jet component may be affected by contributions from depth up to about 150 nm.

Spatiotemporal synchronization of drift waves in a magnetron sputtering plasma

Czech Academy of Sciences Publication Activity Database

Martines, E.; Zuin, M.; Cavazzana, R.; Adámek, Jiří; Antoni, V.; Serianni, G.; Spolaore, M.; Vianello, N.

2014-01-01

Roč. 21, č. 10 (2014), s. 102309-102309 ISSN 1070-664X Institutional support: RVO:61389021 Keywords : Drift waves * Magnetron sputtering plasma * Spatiotemporal synchronization Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.142, year: 2014 http://dx.doi.org/10.1063/1.4898693

Study on re-sputtering during CN{sub x} film deposition through spectroscopic diagnostics of plasma

Energy Technology Data Exchange (ETDEWEB)

Liang, Peipei; Yang, Xu; Li, Hui; Cai, Hua [Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Sun, Jian; Xu, Ning [Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433 (China); Wu, Jiada, E-mail: jdwu@fudan.edu.cn [Department of Optical Science and Engineering, Fudan University, Shanghai 200433 (China); Shanghai Engineering Research Center of Ultra-Precision Optical Manufacturing, Fudan University, Shanghai 200433 (China); Engineering Research Center of Advanced Lighting Technology, Ministry of Education, Fudan University, Shanghai 200433 (China)

2015-10-15

A nitrogen-carbon plasma was generated during the deposition of carbon nitride (CN{sub x}) thin films by pulsed laser ablation of a graphite target in a discharge nitrogen plasma, and the optical emission of the generated nitrogen-carbon plasma was measured for the diagnostics of the plasma and the characterization of the process of CN{sub x} film deposition. The nitrogen-carbon plasma was recognized to contain various species including nitrogen molecules and molecular ions excited in the ambient N{sub 2} gas, carbon atoms and atomic ions ablated from the graphite target and CN radicals. The temporal evolution and spatial distribution of the CN emission and their dependence on the substrate bias voltage show two groups of CN radicals flying in opposite directions. One represents the CN radicals formed as the products of the reactions occurring in the nitrogen-carbon plasma, revealing the reactive deposition of CN{sub x} film due to the reactive expansion of the ablation carbon plasma in the discharge nitrogen plasma and the effective formation of gaseous CN radicals as precursors for CN{sub x} film growth. The other one represents the CN radicals re-sputtered from the growing CN{sub x} film by energetic plasma species, evidencing the re-sputtering of the growing film accompanying film growth. And, the re-sputtering presents ion-induced sputtering features.

Sputtering of Lunar Regolith Simulant by Protons and Multicharged Heavy Ions at Solar Wind Energies

International Nuclear Information System (INIS)

Meyer, Fred W.; Harris, Peter R.; Taylor, C.N.; Meyer, Harry M. III; Barghouty, N.; Adams, J. Jr.

2011-01-01

We report preliminary results on sputtering of a lunar regolith simulant at room temperature by singly and multiply charged solar wind ions using quadrupole and time-of-flight (TOF) mass spectrometry approaches. Sputtering of the lunar regolith by solar-wind heavy ions may be an important particle source that contributes to the composition of the lunar exosphere, and is a possible mechanism for lunar surface ageing and compositional modification. The measurements were performed in order to assess the relative sputtering efficiency of protons, which are the dominant constituent of the solar wind, and less abundant heavier multicharged solar wind constituents, which have higher physical sputtering yields than same-velocity protons, and whose sputtering yields may be further enhanced due to potential sputtering. Two different target preparation approaches using JSC-1A AGGL lunar regolith simulant are described and compared using SEM and XPS surface analysis.

Study of Au- production in a plasma-sputter type negative ion source

International Nuclear Information System (INIS)

Okabe, Yushirou.

1991-10-01

A negative ion source of plasma-sputter type has been constructed for the purpose of studying physical processes which take place in the ion source. Negative ions of gold are produced on the gold target which is immersed in an argon discharge plasma and biased negatively with respect to the plasma. The work function of the target surface was lowered by the deposition of Cs on the target. An in-situ method has been developed to determine the work function of the target surface in the ion source under discharge conditions. The observed minimum work function of a cesiated gold surface in an argon plasma was 1.3 eV, when the negative ion production rate took the maximum value. The production rate increased monotonically and saturated when the surface work function was reduced from 1.9 eV to 1.3 eV. The dependence of Au - production rate on the incident ion energy and on the number of the incident ion was studied. From the experimental results, it is shown that the sputtering process is an important physical process for the negative ion production in the plasma-sputter type negative ion source. The energy distribution function was also measured. When the bias voltage was smaller than 280 V, the high energy component in the distribution decreased as the target voltage was decreased. Therefore, the energy spread ΔE, of the observed negative ion energy distribution also decreased. This tendency is also seen in the energy spectrum of Cu atoms sputtered in normal direction by Ar + ions. (J.P.N.)

Targets on the basis of ferrites and high-temperature superconductors for ion-plasma sputtering

International Nuclear Information System (INIS)

Lepeshev, A.A.; Saunin, V.N.; Telegin, S.V.; Polyakova, K.P.; Seredkin, V.A.; Pol'skij, A.I.

2000-01-01

Paper describes a method to produce targets for ion-plasma sputtering using plasma splaying of the appropriate powders on a cooled metal basis. Application of the plasma process was demonstrated to enable to produce complex shaped targets under the controlled atmosphere on the basis of ceramic materials ensuring their high composition homogeneity, as well as, reliable mechanical and thermal contact of the resultant coating with the base. One carried out experiments in ion-plasma sputtering of targets to prepare ferrite polycrystalline films to be used in magnetooptics and to prepare high-temperature superconductor epitaxial films [ru

Arc generation from sputtering plasma-dielectric inclusion interactions

CERN Document Server

Wickersham, C E J; Fan, J S

2002-01-01

Arcing during sputter deposition and etching is a significant cause of particle defect generation during device fabrication. In this article we report on the effect of aluminum oxide inclusion size, shape, and orientation on the propensity for arcing during sputtering of aluminum targets. The size, shape, and orientation of a dielectric inclusion plays a major role in determining the propensity for arcing and macroparticle emission. In previous studies we found that there is a critical inclusion size required for arcing to occur. In this article we used high-speed videos, electric arc detection, and measurements of particle defect density on wafers to study the effect of Al sub 2 O sub 3 inclusion size, shape, and orientation on arc rate, intensity, and silicon wafer particle defect density. We found that the cross-sectional area of the inclusion exposed to the sputtering plasma is the critical parameter that determines the arc rate and rate of macroparticle emission. Analysis of the arc rate, particle defect...

A condition for scrape-off plasmas in self-sputtering

International Nuclear Information System (INIS)

Sengoku, Seio; Azumi, Masahumi; Matsumoto, Yasuo; Maeda, Hikosuke; Shimomura, Yasuo

1978-10-01

Behavior of self-sputtered impurities from limiters or divertor neutralizer plates was investigated. The upper limit of boundary plasma temperature determined under the condition that the impurities of wall materials was not on increase is shown to be low. (author)

Measurements of sputtering yields for low-energy plasma ions

International Nuclear Information System (INIS)

Nishi, M.; Yamada, M.; Suckewer, S.; Rosengaus, E.

1979-04-01

Sputtering yields of various wall/limiter materials of fusion devices have been extensively measured in the relevant plasma environment for low-energy light ions (E 14 cm -3 and electron temperature up to 10eV. Target materials used were C (graphite), Ti, Mo, Ta, W, and Fe (stainless steel). In order to study the dependence of the sputtering yields on the incident energy of ions, the target samples were held at negative bias voltage up to 300V. The sputtering yields were determined by a weight-loss method and by spectral line intensity measurements. The data obtained in the present experiment agree well with those previously obtained at the higher energies (E greater than or equal to 200eV) by other authors using different schemes; the present data also extend to substantially lower energies (E approx. > 30eV) than hitherto

Preparation of Pb(Zr, Ti)O3 Thin Films by Plasma-Assisted Sputtering

Science.gov (United States)

Hioki, Tsuyoshi; Akiyama, Masahiko; Ueda, Tomomasa; Onozuka, Yutaka; Suzuki, Kouji

1999-09-01

A novel plasma-assisted RF magnetron sputtering system with an immersed coil antenna between a target and a substrate was applied for preparing Pb(Zr, Ti)O3 (PZT) thin films. The antenna enabled the generation of inductively coupled plasma (ICP) independently of the target RF source. The plasma assisted by the antenna resulted in the changes of ion fluxes and these energy distributions irradiating to the substrate. The crystalline phase of the deposited PZT thin films was occupied by the perovskite phase depending on the antenna power. In addition, a high deposition rate, modified uniformity of film thickness, and a dense film structure with large columnar grains were obtained as a result of effects of the assisted plasma. The application of the plasma-assisted sputtering method may enable the preparation of PZT thin films that haveexcellent properties.

Sputter deposition of tantalum-nitride films on copper using an rf-plasma

International Nuclear Information System (INIS)

Walter, K.C.; Fetherston, R.P.; Sridharan, K.; Chen, A.; Shamim, M.M.; Conrad, J.R.

1994-01-01

A tantalum-nitride film was successfully deposited at ambient temperature on copper with a modified ion-assisted-deposition (IAD) technique. The process uses an argon and nitrogen plasma to sputter deposit from a tantalum rf-cathode and ion implant the deposited film simultaneously. Both argon and nitrogen ions are used for sputtering and ion implantation. Auger spectroscopy and x-ray diffraction were used to characterize the resulting film

Sputtering of water ice

International Nuclear Information System (INIS)

Baragiola, R.A.; Vidal, R.A.; Svendsen, W.; Schou, J.; Shi, M.; Bahr, D.A.; Atteberrry, C.L.

2003-01-01

We present results of a range of experiments of sputtering of water ice together with a guide to the literature. We studied how sputtering depends on the projectile energy and fluence, ice growth temperature, irradiation temperature and external electric fields. We observed luminescence from the decay of H(2p) atoms sputtered by heavy ion impact, but not bulk ice luminescence. Radiolyzed ice does not sputter under 3.7 eV laser irradiation

ERO modeling of Cr sputtering in the linear plasma device PSI-2

Science.gov (United States)

Eksaeva, A.; Borodin, D.; Kreter, A.; Nishijima, D.; Pospieszczyk, A.; Schlummer, T.; Ertmer, S.; Terra, A.; Unterberg, B.; Kirschner, A.; Romazanov, J.; Brezinsek, S.; Rasinski, M.; Henderson, S.; O'Mullane, M.; Summers, H.; Bluteau, M.; Marenkov, E.

2017-12-01

The prediction of the first wall deterioration and possible plasma contamination by impurities is a high priority task for ITER. 3D Monte-Carlo code ERO is a tool for modeling of eroded impurity transport and spectroscopy in plasma devices useful for experiment interpretation. Chromium (Cr) is a fusion-relevant reactor wall element (e.g. component of RAFM steels expected for use in DEMO). Linear plasma devices including PSI-2 are effective tools for investigations of plasma-surface interaction effects, allowing continuous plasma operation and good control over irradiation parameters. Experiments on Cr sputtering were conducted at PSI-2. In these experiments the Cr erosion was measured by three techniques: mass loss of the sample, quartz micro-balance of deposited impurities at a distance from it and optical emission spectroscopy. Experiments were modeled with the 3D Monte-Carlo code ERO, previously validated by application to similar experiments with tungsten (W). The simulations are demonstrated to reproduce the main experimental outcomes proving the quality of the sputtering data used. A significant focuses of the paper is the usage and validation of atomic data (resent metastable-resolved dataset from ADAS) for interpretation of Cr spectroscopy. Initial population of quasi-metastable state was fitted by matching the modeling with the experimental line intensity profiles.

Remote plasma sputtering of indium tin oxide thin films for large area flexible electronics

International Nuclear Information System (INIS)

Yeadon, A.D.; Wakeham, S.J.; Brown, H.L.; Thwaites, M.J.; Whiting, M.J.; Baker, M.A.

2011-01-01

Indium tin oxide (ITO) thin films with a specific resistivity of 3.5 × 10 −4 Ω cm and average visible light transmission (VLT) of 90% have been reactively sputtered onto A4 Polyethylene terephthalate (PET), glass and silicon substrates using a remote plasma sputtering system. This system offers independent control of the plasma density and the target power enabling the effect of the plasma on ITO properties to be studied. Characterization of ITO on glass and silicon has shown that increasing the plasma density gives rise to a decrease in the specific resistivity and an increase in the optical band gap of the ITO films. Samples deposited at plasma powers of 1.5 kW, 2.0 kW and 2.5 kW and optimized oxygen flow rates exhibited specific resistivity values of 3.8 × 10 −4 Ω cm, 3.7 × 10 −4 Ω cm and 3.5 × 10 −4 Ω cm and optical gaps of 3.48 eV, 3.51 eV and 3.78 eV respectively. The increase in plasma density also influenced the crystalline texture and the VLT increased from 70 to 95%, indicating that more oxygen is being incorporated into the growing film. It has been shown that the remote plasma sputter technique can be used in an in-line process to produce uniform ITO coatings on PET with specific resistivities of between 3.5 × 10 −4 and 4.5 × 10 −4 Ω cm and optical transmission of greater than 85% over substrate widths of up to 30 cm.

Hydrophobization of track membrane surface by ion-plasma sputtering method

Science.gov (United States)

Kuklin, I. E.; Khlebnikov, N. A.; Barashev, N. R.; Serkov, K. V.; Polyakov, E. V.; Zdorovets, M. V.; Borgekov, D. B.; Zhidkov, I. S.; Cholakh, S. O.; Kozlovskiy, A. L.

2017-09-01

This article reviews the possibility of applying inorganic coatings of metal compounds on PTM by ion-plasma sputtering. The main aim of this research is to increase the contact angle of PTM surfaces and to impart the properties of a hydrophobic material to it. After the modification, the initial contact angle increased from 70° to 120°.

Modeling and analysis of surface roughness effects on sputtering, reflection, and sputtered particle transport

International Nuclear Information System (INIS)

Brooks, J.N.; Ruzic, D.N.

1990-01-01

The microstructure of the redeposited surface in tokamaks may affect sputtering and reflection properties and subsequent particle transport. This subject has been studied numerically using coupled models/codes for near-surface plasma particle kinetic transport (WBC code) and rough surface sputtering (fractal-TRIM). The coupled codes provide an overall Monte Carlo calculation of the sputtering cascade resulting from an initial flux of hydrogen ions. Beryllium, carbon, and tungsten surfaces are analyzed for typical high recycling, oblique magnetic field, divertor conditions. Significant variations in computed sputtering rates are found with surface roughness. Beryllium exhibits high D-T and self-sputtering coefficients for the plasma regime studied (T e = 30-75 eV). Carbon and tungsten sputtering is significantly lower. 9 refs., 6 figs., 1 tab

Simulation calculations of physical sputtering and reflection coefficient of plasma-irradiated carbon surface

International Nuclear Information System (INIS)

Kawamura, T.; Ono, T.; Yamamura, Y.

1994-08-01

Physical sputtering yields from the carbon surface irradiated by the boundary plasma are obtained with the use of a Monte Carlo simulation code ACAT. The yields are calculated for many random initial energy and angle values of incident protons or deuterons with a Maxwellian velocity distribution, and then averaged. Here the temperature of the boundary plasma, the sheath potential and the angle δ between the magnetic field line and the surface normal are taken into account. A new fitting formula for an arrangement of the numerical data of sputtering yield is introduced, in which six fitting parameters are determined from the numerical results and listed. These results provide a way to estimate the erosion of carbon materials irradiated by boundary plasma. The particle reflection coefficients for deuterons and their neutrals from a carbon surface are also calculated by the same code and presented together with, for comparison, that for the case of monoenergetic normal incidence. (author)

Fabrication and characterization of He-charged ODS-FeCrNi films deposited by a radio-frequency plasma magnetron sputtering technique

Science.gov (United States)

Song, Liang; Wang, Xianping; Wang, Le; Zhang, Ying; Liu, Wang; Jiang, Weibing; Zhang, Tao; Fang, Qianfeng; Liu, Changsong

2017-04-01

He-charged oxide dispersion strengthened (ODS) FeCrNi films were prepared by a radio-frequency (RF) plasma magnetron sputtering method in a He and Ar mixed atmosphere at 150 °C. As a comparison, He-charged FeCrNi films were also fabricated at the same conditions through direct current (DC) plasma magnetron sputtering. The doping of He atoms and Y2O3 in the FeCrNi films was realized by the high backscattered rate of He ions and Y2O3/FeCrNi composite target sputtering method, respectively. Inductive coupled plasma (ICP) and x-ray photoelectron spectroscopy (XPS) analysis confirmed the existence of Y2O3 in FeCrNi films, and Y2O3 content hardly changed with sputtering He/Ar ratio. Cross-sectional scanning electron microscopy (SEM) shows that the FeCrNi films were composed of dense columnar nanocrystallines and the thickness of the films was obviously dependent on He/Ar ratio. Nanoindentation measurements revealed that the FeCrNi films fabricated through DC/RF plasma magnetron sputtering methods exhibited similar hardness values at each He/Ar ratio, while the dispersion of Y2O3 apparently increased the hardness of the films. Elastic recoil detection (ERD) showed that DC/RF magnetron sputtered FeCrNi films contained similar He amounts (˜17 at.%). Compared with the minimal change of He level with depth in DC-sputtered films, the He amount decreases gradually in depth in the RF-sputtered films. The Y2O3-doped FeCrNi films were shown to exhibit much smaller amounts of He owing to the lower backscattering possibility of Y2O3 and the inhibition effect of nano-sized Y2O3 particles on the He element.

Nano-structuring of PTFE surface by plasma treatment, etching, and sputtering with gold

International Nuclear Information System (INIS)

Reznickova, Alena; Kolska, Zdenka; Hnatowicz, Vladimir; Svorcik, Vaclav

2011-01-01

Properties of pristine, plasma modified, and etched (by water and methanol) polytetrafluoroethylene (PTFE) were studied. Gold nanolayers sputtered on this modified PTFE have been also investigated. Contact angle, measured by goniometry, was studied as a function of plasma exposure and post-exposure aging times. Degradation of polymer chains was examined by etching of plasma modified PTFE in water or methanol. The amount of ablated and etched layer was measured by gravimetry. In the next step the pristine, plasma modified, and etched PTFE was sputtered with gold. Changes in surface morphology were observed using atomic force microscopy. Chemical structure of modified polymers was characterized by X-ray photoelectron spectroscopy (XPS). Surface chemistry of the samples was investigated by electrokinetic analysis. Sheet resistance of the gold layers was measured by two-point technique. The contact angle of the plasma modified PTFE decreases with increasing exposure time. The PTFE amount, ablated by the plasma treatment, increases with the plasma exposure time. XPS measurements proved that during the plasma treatment the PTFE macromolecular chains are degraded and oxidized and new –C–O–C–, –C=O, and –O–C=O groups are created in modified surface layer. Surface of the plasma modified PTFE is weakly soluble in methanol and intensively soluble in water. Zeta potential and XPS shown dramatic changes in PTFE surface chemistry after the plasma exposure, water etching, and gold deposition. When continuous gold layer is formed a rapid decrease of the sheet resistance of the gold layer is observed.

Dependence of Au- production upon the target work function in a plasma-sputter-type negative ion source

International Nuclear Information System (INIS)

Okabe, Yushirou; Sasao, Mamiko; Fujita, Junji; Yamaoka, Hitoshi; Wada, Motoi.

1991-01-01

A method to measure the work function of the target surface in a plasma-sputter-type negative ion source has been developed. The method can determine the work function by measuring the photoelectric current induced by two lasers (He-Ne, Ar + laser). The dependence of Au - production upon the work function of the target surface in the ion source was studied using this method. The time variation of the target work function and Au - production rate were measured during the cesium coverage decrease due to the plasma ion sputtering. The observed minimum work function of a cesiated gold surface in an Ar plasma was 1.3 eV. At the same time, the negative ion production rate (Au - current/target current) took the maximum value. The negative ion production rate indicated the same dependence on the incident ion energy as that of the sputtering rate when the work function was constant. (author)

Comparative study of nanocomposites prepared by pulsed and dc sputtering combined with plasma polymerization suitable for photovoltaic device applications

International Nuclear Information System (INIS)

Hussain, Amreen A.; Pal, Arup R.; Kar, Rajib; Bailung, Heremba; Chutia, Joyanti; Patil, Dinkar S.

2014-01-01

Plasma processing, a single step method for production of large area composite films, is employed to deposit plasma polymerized aniline-Titanium dioxide (PPani-TiO 2 ) nanocomposite thin films. The deposition of PPani-TiO 2 nanocomposite films are made using reactive magnetron sputtering and plasma polymerization combined process. This study focuses on the direct comparison between continuous and pulsed dc magnetron sputtering techniques of titanium in combination with rf plasma polymerization of aniline. The deposited PPani-TiO 2 nanocomposite films are characterized and discussed in terms of structural, morphological and optical properties. A self powered hybrid photodetector has been developed by plasma based process. The proposed method provides a new route where the self-assembly of molecules, that is, the spontaneous association of atomic or molecular building blocks under plasma environment, emerge as a successful strategy to form well-defined structural and morphological units of nanometer dimensions. - Highlights: • PPani-TiO 2 nanocomposite by pulsed and dc sputtering with rf plasma polymerization. • In-situ and Ex-situ H 2 SO 4 doping in PPani-TiO 2 nanocomposite. • PPani-TiO 2 nanocomposite based self-powered-hybrid photodetector

Experimental study of the discharge in the low pressure plasma jet sputtering system

Czech Academy of Sciences Publication Activity Database

Klusoň, J.; Kudrna, P.; Kolpaková, A.; Picková, I.; Hubička, Zdeněk; Tichý, M.

2013-01-01

Roč. 53, č. 1 (2013), s. 10-15 ISSN 0863-1042 Institutional support: RVO:68378271 Keywords : hollow cathode * plasma jet sputtering system * Langmuir probe Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.983, year: 2013

Semi-empirical formulas for sputtering yield

International Nuclear Information System (INIS)

Yamamura, Yasumichi

1994-01-01

When charged particles, electrons, light and so on are irradiated on solid surfaces, the materials are lost from the surfaces, and this phenomenon is called sputtering. In order to understand sputtering phenomenon, the bond energy of atoms on surfaces, the energy given to the vicinity of surfaces and the process of converting the given energy to the energy for releasing atoms must be known. The theories of sputtering and the semi-empirical formulas for evaluating the dependence of sputtering yield on incident energy are explained. The mechanisms of sputtering are that due to collision cascade in the case of heavy ion incidence and that due to surface atom recoil in the case of light ion incidence. The formulas for the sputtering yield of low energy heavy ion sputtering, high energy light ion sputtering and the general case between these extreme cases, and the Matsunami formula are shown. At the stage of the publication of Atomic Data and Nuclear Data Tables in 1984, the data up to 1983 were collected, and about 30 papers published thereafter were added. The experimental data for low Z materials, for example Be, B and C and light ion sputtering data were reported. The combination of ions and target atoms in the collected sputtering data is shown. The new semi-empirical formula by slightly adjusting the Matsunami formula was decided. (K.I.)

Comparisons of physical and chemical sputtering in high density divertor plasmas with the Monte Carlo Impurity (MCI) transport model

International Nuclear Information System (INIS)

Evans, T.E.; Loh, Y.S.; West, W.P.; Finkenthal, D.F.

1997-11-01

The MCI transport model was used to compare chemical and physical sputtering for a DIII-D divertor plasma near detachment. With physical sputtering alone the integrated carbon influx was 8.4 x 10 19 neutral/s while physical plus chemical sputtering produced an integrated carbon influx of 1.7 x 10 21 neutrals/s. The average carbon concentration in the computational volume increased from 0.012% with only physical sputtering to 0.182% with both chemical and physical sputtering. This increase in the carbon inventory produced more radiated power which is in better agreement with experimental measurements

Comparative study of nanocomposites prepared by pulsed and dc sputtering combined with plasma polymerization suitable for photovoltaic device applications

Energy Technology Data Exchange (ETDEWEB)

Hussain, Amreen A. [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Pal, Arup R., E-mail: arpal@iasst.gov.in [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Kar, Rajib [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai (India); Bailung, Heremba; Chutia, Joyanti [Physical Sciences Division, Institute of Advanced Study in Science and Technology, Guwahati, Assam (India); Patil, Dinkar S. [Laser and Plasma Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai (India)

2014-12-15

Plasma processing, a single step method for production of large area composite films, is employed to deposit plasma polymerized aniline-Titanium dioxide (PPani-TiO{sub 2}) nanocomposite thin films. The deposition of PPani-TiO{sub 2} nanocomposite films are made using reactive magnetron sputtering and plasma polymerization combined process. This study focuses on the direct comparison between continuous and pulsed dc magnetron sputtering techniques of titanium in combination with rf plasma polymerization of aniline. The deposited PPani-TiO{sub 2} nanocomposite films are characterized and discussed in terms of structural, morphological and optical properties. A self powered hybrid photodetector has been developed by plasma based process. The proposed method provides a new route where the self-assembly of molecules, that is, the spontaneous association of atomic or molecular building blocks under plasma environment, emerge as a successful strategy to form well-defined structural and morphological units of nanometer dimensions. - Highlights: • PPani-TiO{sub 2} nanocomposite by pulsed and dc sputtering with rf plasma polymerization. • In-situ and Ex-situ H{sub 2}SO{sub 4} doping in PPani-TiO{sub 2} nanocomposite. • PPani-TiO{sub 2} nanocomposite based self-powered-hybrid photodetector.

WO.sub.3./sub. thin films prepared by sedimentation and plasma sputtering

Czech Academy of Sciences Publication Activity Database

Olejníček, Jiří; Brunclíková, Michaela; Kment, Š.; Hubička, Zdeněk; Kmentová, N.; Kšírová, Petra; Čada, Martin; Zlámal, M.; Krýsa, J.

2017-01-01

Roč. 318, Jun (2017), s. 281-288 ISSN 1385-8947 R&D Projects: GA TA ČR(CZ) TF01000084; GA ČR(CZ) GA15-00863S; GA TA ČR TA03010743; GA ČR GAP108/12/2104 Institutional support: RVO:68378271 Keywords : WO 3 * thin films * water splitting * pulsed magnetron sputtering * sedimentation * photo-electro-chemistry Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 6.216, year: 2016

One-dimensional analysis of the rate of plasma-assisted sputter deposition

International Nuclear Information System (INIS)

Palmero, A.; Rudolph, H.; Habraken, F. H. P. M.

2007-01-01

In this article a recently developed model [A. Palmero, H. Rudolph, and F. H. P. M. Habraken, Appl. Phys. Lett. 89, 211501 (2006)] is applied to analyze the transport of sputtered material from the cathode toward the growing film when using a plasma-assisted sputtering deposition technique. The argon pressure dependence of the deposition rate of aluminum, silicon, vanadium, chromium, germanium, tantalum, and tungsten under several different experimental conditions has been analyzed by fitting experimental results from the literature to the above-mentioned theory. Good fits are obtained. Three quantities are deduced from the fit: the temperature of the cathode and of the growing film, and the value of the effective cross section for thermalization due to elastic scattering of a sputtered particle on background gas atoms. The values derived from the fits for the growing film and cathode temperature are very similar to those experimentally determined and reported in the literature. The effective cross sections have been found to be approximately the corresponding geometrical cross section divided by the average number of collisions required for the thermalization, implying that the real and effective thermalization lengths have a similar value. Finally, the values of the throw distance appearing in the Keller-Simmons model, as well as its dependence on the deposition conditions have been understood invoking the values of the cathode and film temperature, as well as of the value of the effective cross section. The analysis shows the overall validity of this model for the transport of sputtered particles in sputter deposition

Effect of Wall Material on H– Production in a Plasma Sputter-Type Ion Source

Directory of Open Access Journals (Sweden)

Y. D. M. Ponce

2004-12-01

Full Text Available The effect of wall material on negative hydrogen ion (H– production was investigated in a multicusp plasma sputter-type ion source (PSTIS. Steady-state cesium-seeded hydrogen plasma was generated by a tungsten filament, while H– was produced through surface production using a molybdenum sputter target. Plasma parameters and H– yields were determined from Langmuir probe and Faraday cup measurements, respectively. At an input hydrogen pressure of 1.2 mTorr and optimum plasma discharge parameters Vd = –90 V and Id = –2.25 A, the plasma parameters ne was highest and T–e was lowest as determined from Langmuir probe measurements. At these conditions, aluminum generates the highest ion current density of 0.01697 mA/cm2, which is 64% more than the 0.01085 mA/cm2 that stainless steel produces. The yield of copper, meanwhile, falls between the two materials at 0.01164 mA/cm2. The beam is maximum at Vt = –125 V. Focusing is achieved at VL = –70 V for stainless steel, Vt = –60 V for aluminum, and Vt = –50 V for copper. The results demonstrate that proper selection of wall material can greatly enhance the H– production of the PSTIS.

Impact of Plasma Electron Flux on Plasma Damage-Free Sputtering of Ultrathin Tin-Doped Indium Oxide Contact Layer on p-GaN for InGaN/GaN Light-Emitting Diodes.

Science.gov (United States)

Son, Kwang Jeong; Kim, Tae Kyoung; Cha, Yu-Jung; Oh, Seung Kyu; You, Shin-Jae; Ryou, Jae-Hyun; Kwak, Joon Seop

2018-02-01

The origin of plasma-induced damage on a p -type wide-bandgap layer during the sputtering of tin-doped indium oxide (ITO) contact layers by using radiofrequency-superimposed direct current (DC) sputtering and its effects on the forward voltage and light output power (LOP) of light-emitting diodes (LEDs) with sputtered ITO transparent conductive electrodes (TCE) is systematically studied. Changing the DC power voltage from negative to positive bias reduces the forward voltages and enhances the LOP of the LEDs. The positive DC power drastically decreases the electron flux in the plasma obtained by plasma diagnostics using a cutoff probe and a Langmuir probe, suggesting that the repulsion of plasma electrons from the p -GaN surface can reduce plasma-induced damage to the p -GaN. Furthermore, electron-beam irradiation on p -GaN prior to ITO deposition significantly increases the forward voltages, showing that the plasma electrons play an important role in plasma-induced damage to the p -GaN. The plasma electrons can increase the effective barrier height at the ITO/deep-level defect (DLD) band of p -GaN by compensating DLDs, resulting in the deterioration of the forward voltage and LOP. Finally, the plasma damage-free sputtered-ITO TCE enhances the LOP of the LEDs by 20% with a low forward voltage of 2.9 V at 20 mA compared to LEDs with conventional e-beam-evaporated ITO TCE.

Computer-controlled back scattering and sputtering-experiment using a heavy-ion-accelerator

International Nuclear Information System (INIS)

Becker, H.; Birnbaum, M.; Degenhardt, K.H.; Mertens, P.; Tschammer, V.

1978-12-01

Control and data acquisition of a PDP 11/40 computer and CAMAC instrumentation are reported for an experiment that has been developed to measure sputtering in yields and energy losses for heavy 100 - 300 keV ions in thin metal foils. Besides a quadrupole mass filter or a bending magnet, a multichannel analyser is coupled to the computer, so that also pulse height analysis can be performed under computer control. CAMAC instrumentation and measuring programs are built in a modular form to enable an easy application to other experimental problems. (orig.) 891 KBE/orig. 892 BRE

Electronic sputtering

International Nuclear Information System (INIS)

Johnson, R.E.

1989-01-01

Electronic sputtering covers a range of phenomena from electron and photon stimulated desorption from multilayers to fast heavy ion-induced desorption (sputtering) of biomolecules. In this talk the author attempted. Therefore, to connect the detailed studies of argon ejection from solid argon by MeV ions and keV electrons to the sputtering of low temperatures molecular ices by MeV ions then to biomolecule ejection from organic solids. These are related via changing (dE/dx) e , molecular size, and transport processes occurring in materials. In this regard three distinct regions of (dE/dx) e have been identified. Since the talk this picture has been made explicit using a simple spike model for individual impulsive events in which spike interactions are combined linearly. Since that time also the molecular dynamics programs (at Virginia and Uppsala) have quantified both single atom and dimer processes in solid Ar and the momentum transport in large biomolecule sputtering. 5 refs

Spatiotemporal synchronization of drift waves in a magnetron sputtering plasma

Energy Technology Data Exchange (ETDEWEB)

Martines, E.; Zuin, M.; Cavazzana, R.; Antoni, V.; Serianni, G.; Spolaore, M.; Vianello, N. [Consorzio RFX, Padova (Italy); Adámek, J. [Institute of Plasma Physics AS CR, Prague (Czech Republic)

2014-10-15

A feedforward scheme is applied for drift waves control in a magnetized magnetron sputtering plasma. A system of driven electrodes collecting electron current in a limited region of the explored plasma is used to interact with unstable drift waves. Drift waves actually appear as electrostatic modes characterized by discrete wavelengths of the order of few centimeters and frequencies of about 100 kHz. The effect of external quasi-periodic, both in time and space, travelling perturbations is studied. Particular emphasis is given to the role played by the phase relation between the natural and the imposed fluctuations. It is observed that it is possible by means of localized electrodes, collecting currents which are negligible with respect to those flowing in the plasma, to transfer energy to one single mode and to reduce that associated to the others. Due to the weakness of the external action, only partial control has been achieved.

Spatiotemporal synchronization of drift waves in a magnetron sputtering plasma

International Nuclear Information System (INIS)

Martines, E.; Zuin, M.; Cavazzana, R.; Antoni, V.; Serianni, G.; Spolaore, M.; Vianello, N.; Adámek, J.

2014-01-01

A feedforward scheme is applied for drift waves control in a magnetized magnetron sputtering plasma. A system of driven electrodes collecting electron current in a limited region of the explored plasma is used to interact with unstable drift waves. Drift waves actually appear as electrostatic modes characterized by discrete wavelengths of the order of few centimeters and frequencies of about 100 kHz. The effect of external quasi-periodic, both in time and space, travelling perturbations is studied. Particular emphasis is given to the role played by the phase relation between the natural and the imposed fluctuations. It is observed that it is possible by means of localized electrodes, collecting currents which are negligible with respect to those flowing in the plasma, to transfer energy to one single mode and to reduce that associated to the others. Due to the weakness of the external action, only partial control has been achieved

A High-Intensity, RF Plasma-Sputter Negative Ion Source

International Nuclear Information System (INIS)

Alton, G.D.; Bao, Y.; Cui, B.; Lohwasser, R.; Reed, C.A.; Zhang, T.

1999-01-01

A high-intensity, plasma-sputter negative-ion source based on the use of RF power for plasma generation has been developed that can be operated in either pulsed or dc modes. The source utilizes a high-Q, self-igniting, inductively coupled antenna system, operating at 80 MHz that has been optimized to generate Cs-seeded plasmas at low pressures (typically, - (610 microA); F - (100 microA); Si - (500 microA); S - (500 microA); P - (125 microA); Cl - (200 microA); Ni - (150 microA); Cu - (230 microA); Ge - (125 microA); As - (100 microA); Se - (200 microA); Ag - (70 microA); Pt - (125 microA); Au - (250 microA). The normalized emittance var e psilon n of the source at the 80% contour is: var e psilon n = 7.5 mm.mrad.(MeV) 1/2 . The design principles of the source, operational parameters, ion optics, emittance and intensities for a number of negative-ion species will be presented in this report

Hydrogen and helium trapping in tungsten deposition layers formed by RF plasma sputtering

International Nuclear Information System (INIS)

Kazunari Katayama; Kazumi Imaoka; Takayuki Okamura; Masabumi Nishikawa

2006-01-01

Understanding of tritium behavior in plasma facing materials is an important issue for fusion reactor from viewpoints of fuel control and radiation safety. Tungsten is used as a plasma facing material in the divertor region of ITER. However, investigation of hydrogen isotope behavior in tungsten deposition layer is not sufficient so far. It is also necessary to evaluate an effect of helium on a formation of deposition layer and an accumulation of hydrogen isotopes because helium generated by fusion reaction exists in fusion plasma. In this study, tungsten deposition layers were formed by sputtering method using hydrogen and helium RF plasma. An erosion rate and a deposition rate of tungsten were estimated by weight measurement. Hydrogen and helium retention were investigated by thermal desorption method. Tungsten deposition was performed using a capacitively-coupled RF plasma device equipped with parallel-plate electrodes. A tungsten target was mounted on one electrode which is supplied with RF power at 200 W. Tungsten substrates were mounted on the other electrode which is at ground potential. The plasma discharge was continued for 120 hours where pressure of hydrogen or helium was controlled to be 10 Pa. The amounts of hydrogen and helium released from deposition layers was quantified by a gas chromatograph. The erosion rate of target tungsten under helium plasma was estimated to be 1.8 times larger than that under hydrogen plasma. The deposition rate on tungsten substrate under helium plasma was estimated to be 4.1 times larger than that under hydrogen plasma. Atomic ratio of hydrogen to tungsten in a deposition layer formed by hydrogen plasma was estimated to be 0.17 by heating to 600 o C. From a deposition layer formed by helium plasma, not only helium but also hydrogen was released by heating to 500 o C. Atomic ratios of helium and hydrogen to tungsten were estimated to be 0.080 and 0.075, respectively. The trapped hydrogen is probably impurity hydrogen

Plasma polymer films rf sputtered from PTFE under various argon pressures

Czech Academy of Sciences Publication Activity Database

Stelmashuk, Vitaliy; Biederman, H.; Slavinská, D.; Zemek, Josef; Trchová, Miroslava

2005-01-01

Roč. 77, č. 2 (2005), s. 131-137 ISSN 0042-207X R&D Projects: GA MŠk(CZ) OC 527.10; GA MŠk(CZ) OC 527.90 Grant - others:EUREKAΣ2080(XE) OE57 Institutional research plan: CEZ:AV0Z10100521; CEZ:AV0Z20430508 Keywords : RF sputtering * PTFE * fluorcarbon plasma polymers * thin film * teflon * deposition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.909, year: 2005

Fluence-dependent sputtering yield of micro-architectured materials

Energy Technology Data Exchange (ETDEWEB)

Matthes, Christopher S.R.; Ghoniem, Nasr M., E-mail: ghoniem@ucla.edu; Li, Gary Z.; Matlock, Taylor S.; Goebel, Dan M.; Dodson, Chris A.; Wirz, Richard E.

2017-06-15

Highlights: • Sputtering yield is shown to be transient and heavily dependent on surface architecture. • Fabricated nano- and Microstructures cause geometric re-trapping of sputtered material, which leads to a self-healing mechanism. • Initially, the sputtering yield of micro-architectured Mo is approximately 1/2 the value as that of a planar surface. • The study demonstrates that the sputtering yield is a dynamic property, dependent on the surface structure of a material. • A developed phenomenological model mathematically describes the transient behavior of the sputtering yield as a function of plasma fluence. - Abstract: We present an experimental examination of the relationship between the surface morphology of Mo and its instantaneous sputtering rate as function of low-energy plasma ion fluence. We quantify the dynamic evolution of nano/micro features of surfaces with built-in architecture, and the corresponding variation in the sputtering yield. Ballistic deposition of sputtered atoms as a result of geometric re-trapping is observed, and re-growth of surface layers is confirmed. This provides a self-healing mechanism of micro-architectured surfaces during plasma exposure. A variety of material characterization techniques are used to show that the sputtering yield is not a fundamental property, but that it is quantitatively related to the initial surface architecture and to its subsequent evolution. The sputtering yield of textured molybdenum samples exposed to 300 eV Ar plasma is roughly 1/2 of the corresponding value for flat samples, and increases with ion fluence. Mo samples exhibited a sputtering yield initially as low as 0.22 ± 5%, converging to 0.4 ± 5% at high fluence. The sputtering yield exhibits a transient behavior as function of the integrated ion fluence, reaching a steady-state value that is independent of initial surface conditions. A phenomenological model is proposed to explain the observed transient sputtering phenomenon, and to

Heavy ion irradiation of crystalline water ice. Cosmic ray amorphisation cross-section and sputtering yield

Science.gov (United States)

Dartois, E.; Augé, B.; Boduch, P.; Brunetto, R.; Chabot, M.; Domaracka, A.; Ding, J. J.; Kamalou, O.; Lv, X. Y.; Rothard, H.; da Silveira, E. F.; Thomas, J. C.

2015-04-01

Context. Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. Aims: We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. Methods: We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). Results: The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic stopping power. Conclusions: The final state of cosmic ray irradiation for porous amorphous and crystalline ice, as monitored by infrared spectroscopy, is the same, but with a large difference in cross-section, hence in time scale in an astrophysical context. The cosmic ray water-ice sputtering rates compete with the UV photodesorption yields reported in the literature. The prevalence of direct cosmic ray sputtering over cosmic-ray induced photons photodesorption may be particularly true for ices strongly bonded to the ice mantles surfaces, such as hydrogen-bonded ice structures or more generally the so-called polar ices. Experiments performed at the Grand Accélérateur National d'Ions Lourds (GANIL) Caen, France. Part of this work has been financed by the French INSU-CNRS programme "Physique et Chimie du Milieu Interstellaire" (PCMI) and the ANR IGLIAS.

Carbon dust formation in a cold plasma from cathode sputtering

International Nuclear Information System (INIS)

Arnas, C.; Mouberi, A.; Hassouni, K.; Michau, A.; Lombardi, G.; Bonnin, X.; Benedic, F.; Pegourie, B.

2009-01-01

Nanoparticles are produced in argon glow plasmas where carbon is introduced by sputtering of a graphite cathode. A scaling law of growth is reported on as a function of the discharge time. Two successive stages of growth of concomitant agglomeration and carbon deposition are observed, followed by a final stage of growth by carbon deposition. A model of formation of molecular precursors by coagulation of neutral clusters on the one hand and of neutral-negative clusters on the other hand is presented, based on formation enthalpy and cluster geometry.

Carbon dust formation in a cold plasma from cathode sputtering

Science.gov (United States)

Arnas, C.; Mouberi, A.; Hassouni, K.; Michau, A.; Lombardi, G.; Bonnin, X.; Bénédic, F.; Pégourié, B.

2009-06-01

Nanoparticles are produced in argon glow plasmas where carbon is introduced by sputtering of a graphite cathode. A scaling law of growth is reported on as a function of the discharge time. Two successive stages of growth of concomitant agglomeration and carbon deposition are observed, followed by a final stage of growth by carbon deposition. A model of formation of molecular precursors by coagulation of neutral clusters on the one hand and of neutral-negative clusters on the other hand is presented, based on formation enthalpy and cluster geometry.

Deposition of nanostructured fluorocarbon plasma polymer films by RF magnetron sputtering of polytetrafluoroethylene

Energy Technology Data Exchange (ETDEWEB)

Kylian, Ondrej, E-mail: ondrej.kylian@gmail.com; Drabik, Martin; Polonskyi, Oleksandr; Cechvala, Juraj; Artemenko, Anna; Gordeev, Ivan; Choukourov, Andrei; Matolinova, Iva; Slavinska, Danka; Biederman, Hynek, E-mail: bieder@kmf.troja.mff.cuni.cz

2011-07-29

The RF magnetron sputtering of polytetrafluoroethylene target is studied with the aim to find out conditions leading to the deposition of super-hydrophobic thin films. It is shown that such coatings can be prepared at elevated pressures and a longer distance between the sputtered target and the substrate. This is explained by an increase in the density of longer C{sub x}F{sub y} molecules that reach the substrate and a lower flux of ions and CF{sub 2} radicals on the surface of growing film under such deposition conditions, as observed by optical emission spectroscopy and mass spectrometry. Such changes in plasma composition result in a deposition of rough films having F/C ratio close to 2 as observed by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. These findings clearly distinguish our results from the previous investigations of polytetrafluoroethylene sputtering performed at shorter distances from the target, where either low F/C ratio or low roughness of the deposited films did not allow reaching super-hydrophobic character of the coatings.

Sputtering and inelastic processes

International Nuclear Information System (INIS)

Baranov, I.A.; Tsepelevic, S.O.

1987-01-01

Experimental data and models of a new type of material sputtering with ions of relatively high energies due to inelastic (electron) processes are reviewed. This area of investigations began to develop intensively during the latest years. New experimental data of the authors on differential characteristics of ultradisperse gold and americium dioxide layers with fission fragments are given as well. Practical applications of the new sputtering type are considered as well as setup of possibl experiments at heavy multiply charged ion accelerators

Contribution to the study of sputtering and damage of uranium dioxide by fast heavy ions; Contribution a l'etude de la pulverisation et de l'endommagement du dioxyde d'uranium par les ions lourds rapides

Energy Technology Data Exchange (ETDEWEB)

Schlutig, S

2001-03-01

Swift heavy ion-solid interaction leads in volume to track creation and on the surface to the ejection of particles into the vacuum. To learn more about initial mechanisms of track formation, we are focused on the sputtering of uranium dioxide by fast heavy ions. This present study is exclusively devoted to the influence of the electronic stopping power on the emission of neutral particles and especially on their angular distribution. These measurements are completed by those of the ions emitted from UO{sub 2} targets bombarded with swift heavy ions. The whole experimental results give access to: i) the nature of the sputtered particles; ii) the charge state of the emitted particles; iii) the direction of ejection of the sputtered particles ; iv) the sputtering yields deduced from the angular distributions. These results are compared to the prediction of the sputtering models proposed in the literature and it seems that the supersonic gas flow model is well suited to describe our results. Finally, the sputtering yields are compared with a set of earlier experimental data on uranium dioxide damage obtained by T. Wiss and we observe that only a small fraction of UO{sub 2} monolayers are sputtered. (author)

Nanoscale morphogenesis of nylon-sputtered plasma polymer particles

Science.gov (United States)

Choukourov, Andrei; Shelemin, Artem; Pleskunov, Pavel; Nikitin, Daniil; Khalakhan, Ivan; Hanuš, Jan

2018-05-01

Sub-micron polymer particles are highly important in various fields including astrophysics, thermonuclear fusion and nanomedicine. Plasma polymerization offers the possibility to produce particles with tailor-made size, crosslink density and chemical composition to meet the requirements of a particular application. However, the mechanism of nucleation and growth of plasma polymer particles as well as diversity of their morphology remain far from being clear. Here, we prepared nitrogen-containing plasma polymer particles by rf magnetron sputtering of nylon in a gas aggregation cluster source with variable length. The method allowed the production of particles with roughly constant chemical composition and number density but with the mean size changing from 80 to 320 nm. Atomic Force Microscopy with super-sharp probes was applied to study the evolution of the particle surface topography as they grow in size. Height–height correlation and power spectral density functions were obtained to quantify the roughness exponent α  =  0.78, the growth exponent β  =  0.35, and the dynamic exponent 1/z  =  0.50. The set of critical exponents indicates that the particle surface evolves in a self-affine mode and the overall particle growth is caused by the accretion of polymer-forming species from the gas phase and not by coagulation. Redistribution of the incoming material over the surface coupled with the inhomogeneous distribution of inner stress is suggested as the main factor that determines the morphogenesis of the plasma polymer particles.

Data compilation of angular distributions of sputtered atoms

International Nuclear Information System (INIS)

Yamamura, Yasunori; Takiguchi, Takashi; Tawara, Hiro.

1990-01-01

Sputtering on a surface is generally caused by the collision cascade developed near the surface. The process is in principle the same as that causing radiation damage in the bulk of solids. Sputtering has long been regarded as an undesirable dirty effect which destroys the cathodes and grids in gas discharge tubes or ion sources and contaminates plasma and the surrounding walls. However, sputtering is used today for many applications such as sputter ion sources, mass spectrometers and the deposition of thin films. Plasma contamination and the surface erosion of first walls due to sputtering are still the major problems in fusion research. The angular distribution of the particles sputtered from solid surfaces can possibly provide the detailed information on the collision cascade in the interior of targets. This report presents a compilation of the angular distribution of sputtered atoms at normal incidence and oblique incidence in the various combinations of incident ions and target atoms. The angular distribution of sputtered atoms from monatomic solids at normal incidence and oblique incidence, and the compilation of the data on the angular distribution of sputtered atoms are reported. (K.I.)

An economic analysis of the deposition of electrochromic WO3 via sputtering or plasma enhanced chemical vapor deposition

International Nuclear Information System (INIS)

Garg, D.; Henderson, P.B.; Hollingsworth, R.E.; Jensen, D.G.

2005-01-01

The costs of manufacturing electrochromic WO 3 thin films deposited by either radio frequency plasma enhanced chemical vapor deposition (PECVD) or DC reactive magnetron sputtering of metal targets were modeled. Both inline systems for large area glass substrates and roll-to-roll systems for flexible webs were compared. Costs of capital, depreciation, raw materials, labor, power, and other miscellaneous items were accounted for in the model. The results predict that on similar sized systems, PECVD can produce electrochromic WO 3 for as little as one-third the cost, and have more than 10 times the annual production capacity of sputtering. While PECVD cost is dominated by raw materials, primarily WF 6 , sputtering cost is dominated by labor and depreciation

Spectroscopic ellipsometry on Si/SiO2/graphene tri-layer system exposed to downstream hydrogen plasma: Effects of hydrogenation and chemical sputtering

International Nuclear Information System (INIS)

Eren, Baran; Fu, Wangyang; Marot, Laurent; Calame, Michel; Steiner, Roland; Meyer, Ernst

2015-01-01

In this work, the optical response of graphene to hydrogen plasma treatment is investigated with spectroscopic ellipsometry measurements. Although the electronic transport properties and Raman spectrum of graphene change after plasma hydrogenation, ellipsometric parameters of the Si/SiO2/graphene tri-layer system do not change. This is attributed to plasma hydrogenated graphene still being electrically conductive, since the light absorption of conducting 2D materials does not depend on the electronic band structure. A change in the light transmission can only be observed when higher energy hydrogen ions (30 eV) are employed, which chemically sputter the graphene layer. An optical contrast is still apparent after sputtering due to the remaining traces of graphene and hydrocarbons on the surface. In brief, plasma treatment does not change the light transmission of graphene; and when it does, this is actually due to plasma damage rather than plasma hydrogenation

Energy loss of heavy ion beams in plasma

Energy Technology Data Exchange (ETDEWEB)

Okada, T; Hotta, T [Tokyo Univ. of Agriculture and Technology, Koganei (Japan). Faculty of Technology

1997-12-31

The energy loss of heavy-ion beams (HIB) is studied by means of Vlasov theory and Particle-in-Cell (PIC) simulations in a plasma. The interaction of HIB with a plasma is of central importance for inertial confinement fusion (ICF). A number of studies on the HIB interaction with target plasma have been published. It is important for heavy-ion stopping that the effects of the non-linear interaction of HIB within the Vlasov theory are included. Reported are results of a numerical study of nonlinear effects to the stopping power for HIB in plasma. It is shown that the PIC simulations of collective effects of the stopping power are in a good agreement with the Vlasov theory. (author). 2 tabs., 1 fig., 5 refs.

Atomic and plasma-material interaction data for fusion. V. 7, part B. Particle induced erosion of Be, C and W in fusion plasmas. Part B: Physical sputtering and radiation-enhanced sublimation

International Nuclear Information System (INIS)

Eckstein, W.; Stephens, J.A.; Clark, R.E.H.; Davis, J.W.; Haasz, A.A.; Vietzke, E.; Hirooka, Y.

2001-01-01

The present volume of Atomic and Plasma-Material Interaction Data for Fusion is devoted to a critical review of the physical sputtering and radiation enhanced sublimation (RES) behaviour of fusion plasma-facing materials, in particular carbon, beryllium and tungsten. The present volume is intended to provide fusion reactor designers a detailed survey and parameterization of existing, critically assessed data for the chemical erosion of plasma-facing materials by particle impact. The survey and data compilation is presented for a variety of materials containing the elements C, Be and W (including dopants in carbon materials) and impacting plasma species. The dependencies of physical sputtering and RES yields on the material temperature, incident projectile energy, and incident flux are considered. The main data compilation is presented as separate data sheets indicating the material, impacting plasma species, experimental conditions, and parameterizations in terms of analytic functions

Geometric considerations in magnetron sputtering

International Nuclear Information System (INIS)

Thornton, J.A.

1982-01-01

The recent development of high performance magnetron type discharge sources has greatly enhaced the range of coating applications where sputtering is a viable deposition process. Magnetron sources can provide high current densities and sputtering rates, even at low pressures. They have much reduced substrate heating rates and can be scaled to large sizes. Magnetron sputter coating apparatuses can have a variety of geometric and plasma configurations. The target geometry affects the emission directions of both the sputtered atoms and the energetic ions which are neutralized and reflected at the cathode. This fact, coupled with the long mean free particle paths which are prevalent at low pressures, can make the coating properties very dependent on the apparatus geometry. This paper reviews the physics of magnetron operation and discusses the influences of apparatus geometry on the use of magnetrons for rf sputtering and reactive sputtering, as well as on the microstructure and internal stresses in sputtered metallic coatings. (author) [pt

''Heavy light bullets'' in electron-positron plasma

International Nuclear Information System (INIS)

Berezhiani, V.I.; Mahajan, S.M.

1995-03-01

The nonlinear propagation of circularly polarized electromagnetic waves with relativistically strong amplitudes in an unmagnetized hot electron-positron plasma with a small fraction of ions is investigated. The possibility of finding localized solutions in such a plasma is explored. It is shown that these plasmas support the propagation of ''heavy light bullets''; nondiffracting and nondispersive electromagnetic (EM) pulses with large density bunching. (author). 24 refs, 12 figs

Effect of sputtering on self-damaged recrystallized W mirror specimens

Energy Technology Data Exchange (ETDEWEB)

Voitsenya, V.S. [Institute of Plasma Physics, National Scientific Center “KIPT”, 61108 Kharkov (Ukraine); Balden, M. [Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Belyaeva, A.I. [National Technical University, “Kharkiv Polytechnical Institute”, 61002 Kharkov (Ukraine); Alimov, V.Kh. [Hydrogen Isotope Research Center, University of Toyama, Toyama 930-8555 (Japan); Tyburska-Püschel, B., E-mail: tyburska@engr.wisc.edu [Max-Planck-Institut für Plasmaphysik, EURATOM Association, D-85748 Garching (Germany); Galuza, A.A. [Institute of Electrophysics and Radiation Technologies, NAS of Ukraine, 61002 Kharkov (Ukraine); Kasilov, A.A.; Kolenov, I.V. [Institute of Plasma Physics, National Scientific Center “KIPT”, 61108 Kharkov (Ukraine); Konovalov, V.G. [National Technical University, “Kharkiv Polytechnical Institute”, 61002 Kharkov (Ukraine); Skoryk, O.O.; Solodovchenko, S.I. [Institute of Plasma Physics, National Scientific Center “KIPT”, 61108 Kharkov (Ukraine)

2013-03-15

The effect of heavy sputtering and of neutron irradiation simulated by displacement damaging with of 20 MeV W{sup 6+} ions on the optical properties of tungsten mirrors was studied. Ar{sup +} ions with 600 eV of energy were used as imitation of charge exchange atoms ejected from fusion plasma. The ion fluence dependence of the surface topography and the optical properties of polycrystalline, recrystallized tungsten (grain size 20–100 μm) were studied by optical microscopy, interferometry, reflectometry and ellipsometry. Furthermore, after sputtering in total a layer of 3.9 μm in thickness, the orientation and the thickness of the eroded layer of many individual grains was determined by electron backscattering diffraction and confocal laser scanning microscopy. Concluding from the obtained data the neutron irradiation, at least at the damage level would be achieved in ITER, has not to make an additional contribution in the processes developing under impact of charge exchange atoms only.

Plasma polymer-functionalized silica particles for heavy metals removal.

Science.gov (United States)

Akhavan, Behnam; Jarvis, Karyn; Majewski, Peter

2015-02-25

Highly negatively charged particles were fabricated via an innovative plasma-assisted approach for the removal of heavy metal ions. Thiophene plasma polymerization was used to deposit sulfur-rich films onto silica particles followed by the introduction of oxidized sulfur functionalities, such as sulfonate and sulfonic acid, via water-plasma treatments. Surface chemistry analyses were conducted by X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectroscopy. Electrokinetic measurements quantified the zeta potentials and isoelectric points (IEPs) of modified particles and indicated significant decreases of zeta potentials and IEPs upon plasma modification of particles. Plasma polymerized thiophene-coated particles treated with water plasma for 10 min exhibited an IEP of less than 3.5. The effectiveness of developed surfaces in the adsorption of heavy metal ions was demonstrated through copper (Cu) and zinc (Zn) removal experiments. The removal of metal ions was examined through changing initial pH of solution, removal time, and mass of particles. Increasing the water plasma treatment time to 20 min significantly increased the metal removal efficiency (MRE) of modified particles, whereas further increasing the plasma treatment time reduced the MRE due to the influence of an ablation mechanism. The developed particulate surfaces were capable of removing more than 96.7% of both Cu and Zn ions in 1 h. The combination of plasma polymerization and oxidative plasma treatment is an effective method for the fabrication of new adsorbents for the removal of heavy metals.

Spectroscopic ellipsometry on Si/SiO{sub 2}/graphene tri-layer system exposed to downstream hydrogen plasma: Effects of hydrogenation and chemical sputtering

Energy Technology Data Exchange (ETDEWEB)

Eren, Baran [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Fu, Wangyang; Marot, Laurent, E-mail: laurent.marot@unibas.ch; Calame, Michel; Steiner, Roland; Meyer, Ernst [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

2015-01-05

In this work, the optical response of graphene to hydrogen plasma treatment is investigated with spectroscopic ellipsometry measurements. Although the electronic transport properties and Raman spectrum of graphene change after plasma hydrogenation, ellipsometric parameters of the Si/SiO2/graphene tri-layer system do not change. This is attributed to plasma hydrogenated graphene still being electrically conductive, since the light absorption of conducting 2D materials does not depend on the electronic band structure. A change in the light transmission can only be observed when higher energy hydrogen ions (30 eV) are employed, which chemically sputter the graphene layer. An optical contrast is still apparent after sputtering due to the remaining traces of graphene and hydrocarbons on the surface. In brief, plasma treatment does not change the light transmission of graphene; and when it does, this is actually due to plasma damage rather than plasma hydrogenation.

Hydrogen gas driven permeation through tungsten deposition layer formed by hydrogen plasma sputtering

International Nuclear Information System (INIS)

Uehara, Keiichiro; Katayama, Kazunari; Date, Hiroyuki; Fukada, Satoshi

2015-01-01

Highlights: • H permeation tests for W layer formed by H plasma sputtering are performed. • H permeation flux through W layer is larger than that through W bulk. • H diffusivity in W layer is smaller than that in W bulk. • The equilibrium H concentration in W layer is larger than that in W bulk. - Abstract: It is important to evaluate the influence of deposition layers formed on plasma facing wall on tritium permeation and tritium retention in the vessel of a fusion reactor from a viewpoint of safety. In this work, tungsten deposition layers having different thickness and porosity were formed on circular nickel plates by hydrogen RF plasma sputtering. Hydrogen permeation experiment was carried out at the temperature range from 250 °C to 500 °C and at hydrogen pressure range from 1013 Pa to 101,300 Pa. The hydrogen permeation flux through the nickel plate with tungsten deposition layer was significantly smaller than that through a bare nickel plate. This indicates that a rate-controlling step in hydrogen permeation was not permeation through the nickel plate but permeation though the deposition layer. The pressure dependence on the permeation flux differed by temperature. Hydrogen permeation flux through tungsten deposition layer is larger than that through tungsten bulk. From analysis of the permeation curves, it was indicated that hydrogen diffusivity in tungsten deposition layer is smaller than that in tungsten bulk and the equilibrium hydrogen concentration in tungsten deposition layer is enormously larger than that in tungsten bulk at same hydrogen pressure.

Development of an inductively coupled impulse sputtering source for coating deposition

Science.gov (United States)

Loch, Daniel Alexander Llewellyn

In recent years, highly ionised pulsed plasma processes have had a great impact on improving the coating performance of various applications, such as for cutting tools and ITO coatings, allowing for a longer service life and improved defect densities. These improvements stem from the higher ionisation degree of the sputtered material in these processes and with this the possibility of controlling the flux of sputtered material, allowing the regulation of the hardness and density of coatings and the ability to sputter onto complex contoured substrates. The development of Inductively Coupled Impulse Sputtering (ICIS) is aimed at the potential of utilising the advantages of highly ionised plasma for the sputtering of ferromagnetic material. In traditional magnetron based sputter processes ferromagnetic materials would shunt the magnetic field of the magnetron, thus reducing the sputter yield and ionisation efficiency. By generating the plasma within a high power pulsed radio frequency (RF) driven coil in front of the cathode, it is possible to remove the need for a magnetron by applying a high voltage pulsed direct current to the cathode attracting argon ions from the plasma to initiate sputtering. This is the first time that ICIS technology has been deployed in a sputter coating system. To study the characteristics of ICIS, current and voltage waveforms have been measured to examine the effect of increasing RF-power. Plasma analysis has been conducted by optical emission spectroscopy to investigate the excitation mechanisms and the emission intensity. These are correlated to the set RF-power by modelling assumptions based on electron collisions. Mass spectroscopy is used to measure the plasma potential and ion energy distribution function. Pure copper, titanium and nickel coatings have been deposited on silicon with high aspect ratio via to measure the deposition rate and characterise the microstructure. For titanium and nickel the emission modelling results are in

Composite materials obtained by the ion-plasma sputtering of metal compound coatings on polymer films

Science.gov (United States)

Khlebnikov, Nikolai; Polyakov, Evgenii; Borisov, Sergei; Barashev, Nikolai; Biramov, Emir; Maltceva, Anastasia; Vereshchagin, Artem; Khartov, Stas; Voronin, Anton

2016-01-01

In this article, the principle and examples composite materials obtained by deposition of metal compound coatings on polymer film substrates by the ion-plasma sputtering method are presented. A synergistic effect is to obtain the materials with structural properties of the polymer substrate and the surface properties of the metal deposited coatings. The technology of sputtering of TiN coatings of various thicknesses on polyethylene terephthalate films is discussed. The obtained composites are characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and scanning tunneling microscopy (STM) is shown. The examples of application of this method, such as receiving nanocomposite track membranes and flexible transparent electrodes, are considered.

Comparison of gate dielectric plasma damage from plasma-enhanced atomic layer deposited and magnetron sputtered TiN metal gates

Energy Technology Data Exchange (ETDEWEB)

Brennan, Christopher J.; Neumann, Christopher M.; Vitale, Steven A., E-mail: steven.vitale@ll.mit.edu [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 (United States)

2015-07-28

Fully depleted silicon-on-insulator transistors were fabricated using two different metal gate deposition mechanisms to compare plasma damage effects on gate oxide quality. Devices fabricated with both plasma-enhanced atomic-layer-deposited (PE-ALD) TiN gates and magnetron plasma sputtered TiN gates showed very good electrostatics and short-channel characteristics. However, the gate oxide quality was markedly better for PE-ALD TiN. A significant reduction in interface state density was inferred from capacitance-voltage measurements as well as a 1200× reduction in gate leakage current. A high-power magnetron plasma source produces a much higher energetic ion and vacuum ultra-violet (VUV) photon flux to the wafer compared to a low-power inductively coupled PE-ALD source. The ion and VUV photons produce defect states in the bulk of the gate oxide as well as at the oxide-silicon interface, causing higher leakage and potential reliability degradation.

An economic analysis of the deposition of electrochromic WO{sub 3} via sputtering or plasma enhanced chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Garg, D. [Air Products and Chemicals Inc., 7201 Hamilton Blvd., Allentown, PA 18195-7201 (United States); Henderson, P.B. [Air Products and Chemicals Inc., 7201 Hamilton Blvd., Allentown, PA 18195-7201 (United States)]. E-mail: henderpb@airproducts.co; Hollingsworth, R.E. [ITN Energy Systems Inc., 8130 Shaffer Pkwy, Littleton, CO 80127 (United States); Jensen, D.G. [ITN Energy Systems Inc., 8130 Shaffer Pkwy, Littleton, CO 80127 (United States)

2005-06-15

The costs of manufacturing electrochromic WO{sub 3} thin films deposited by either radio frequency plasma enhanced chemical vapor deposition (PECVD) or DC reactive magnetron sputtering of metal targets were modeled. Both inline systems for large area glass substrates and roll-to-roll systems for flexible webs were compared. Costs of capital, depreciation, raw materials, labor, power, and other miscellaneous items were accounted for in the model. The results predict that on similar sized systems, PECVD can produce electrochromic WO{sub 3} for as little as one-third the cost, and have more than 10 times the annual production capacity of sputtering. While PECVD cost is dominated by raw materials, primarily WF{sub 6}, sputtering cost is dominated by labor and depreciation.

Development of negative heavy ion sources for plasma potential measurement

International Nuclear Information System (INIS)

Sasao, M.; Okabe, Y.; Fujisawa, A.; Iguchi, H.; Fujita, J.; Yamaoka, H.; Wada, M.

1991-10-01

A plasma sputter negative ion source was studied for its applicability to the potential measurement of a fusion plasma. Both the beam current density and the beam energy spread are key issues. Energy spectra of a self extracted Au - beam from the source were measured under the condition of a constant work function of the production surface. The full width of half maximum (FWHM) increases from 3 eV to 9 eV monotonically as the target voltage increases from 50 V to 300 V, independently from the target surface work function of 2.2 - 3 eV. (author)

Cluster ion formation during sputtering processes: a complementary investigation by ToF-SIMS and plasma ion mass spectrometry

International Nuclear Information System (INIS)

Welzel, T; Ellmer, K; Mändl, S

2014-01-01

Plasma ion mass spectrometry using a plasma process monitor (PPM) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) have been complementarily employed to investigate the sputtering and ion formation processes of Al-doped zinc oxide. By comparing the mass spectra, insights on ion formation and relative cross-sections have been obtained: positive ions as measured during magnetron sputtering by PPM are originating from the plasma while those in SIMS start at the surface leading to large differences in the mass spectra. In contrast, negative ions originating at the surface will be accelerated through the plasma sheath. They arrive at the PPM after traversing the plasma nearly collisionless as seen from the rather similar spectra. Hence, it is possible to combine the high mass resolution of ToF-SIMS to obtain insight for separating cluster ions, e.g. Zn x and ZnO y , and the energy resolution of PPM to find fragmentation patterns for negative ions. While the ion formation processes during both experiments can be assumed to be similar, differences may arise due to the lower volume probed by SIMS. In the latter case, there is a chance of small target inhomogeneities being able to be enhanced and lower surface temperatures leading to less outgassing and, thus, retention of volatile compounds. (paper)

Reactive dual magnetron sputtering for large area application

International Nuclear Information System (INIS)

Struempfel, J.

2002-01-01

Production lines for large area coating demand high productivity of reactive magnetron sputtering processes. Increased dynamic deposition rates for oxides and nitrides were already obtained by using of highly powered magnetrons in combination with advanced sputter techniques. However, besides high deposition rates the uniformity of such coatings has to be carefully considered. First the basics of reactive sputtering processes and dual magnetron sputtering are summarized. Different methods for process stabilization and control are commonly used for reactive sputtering. The Plasma Emission Monitor (PE M) offers the prerequisite for fast acting process control derived from the in-situ intensity measurements of a spectral line of the sputtered target material. Combined by multiple Plasma Emission Monitor control loops segmented gas manifolds are able to provide excellent thin film uniformity at high deposition rates. The Dual Magnetron allows a broad range of processing by different power supply modes. Medium frequency, DC and pulsed DC power supplies can be used for high quality layers. Whereas the large area coating of highly isolating layers like TiO 2 or SiO 2 is dominated by MF sputtering best results for coating with transparent conductive oxides are obtained by dual DC powering of the dual magnetron arrangement. (Author)

Composite SiOx/hydrocarbon plasma polymer films prepared by RF magnetron sputtering of SiO2 and polyimide

Czech Academy of Sciences Publication Activity Database

Drabik, M.; Kousal, J.; Pinosh, Y.; Choukourov, A.; Biederman, H.; Slavínská, D.; Macková, Anna; Boldyryeva, Hanna; Pešička, J.

2007-01-01

Roč. 81, č. 7 (2007), s. 920-927 ISSN 0042-207X Institutional research plan: CEZ:AV0Z10480505 Keywords : composite films * magnetron * sputtering * polyimide * SiO2 Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.881, year: 2007

Modification of the electronic properties of As2Se3 films by erbium using ion-plasma sputtering method

International Nuclear Information System (INIS)

Prikhodko, O.Yu.; Sarsembinov, Sh.Sh.; Ryaguzov, A.P.; Maksimova, S.Ya.; Chuprynin, A.S.

2003-01-01

At present one of the vital problems of semiconductor materials studies is production of new light emitting materials for fiber optics, namely for light-emitting diode, emitting at room temperature in the range of minimum absorption of quartz optic fiber. It is well-known that heterostructures based on amorphous semiconductors, containing large concentrations of rare-earth elements have such properties. The method of ion-plasma co-sputtering (IPCM) of the original and doping materials allows us to obtain amorphous semiconductor films with large impurity concentration. This method was used to produce amorphous films of chalcogenide vitreous semiconductors (ChVS), doped with impurities of different chemical nature. But the capability of IPCM for ChVS doping with rare-earth elements has not been studied well yet. Therefore it is interesting to obtain amorphous films of arsenic selenide doped with erbium using IPCM and study its electronic properties. The films were produced using high frequency (13.56 MHz) ion-plasma co-sputtering of combined target of vitreous As 2 Se 3 and a metal. The sputtering of the target was conducted in argon atmosphere. Er concentration in the films varied between 0 and 4 atomic percent. Amorphism of the structure of the obtained films was monitored using X-ray diffraction methods. Electrical and optical properties of Er-doped As 2 Se 3 films and the charge carrier transportation processes were studied. It was determined that doped films significantly differ from the pure ones in the values of main electronic parameters: conductivity, energy activation of conductivity, optical band-gap, drift mobility of electrons and holes and mobility activation energy. Note that common rules of change of electronic parameters of As 2 Se 3 films affected by Er doping agree with the rules, established during modification of As 2 Se 3 films with dopes of transition metals with incomplete 3d-shell (Fe, Ni). Analysis of the obtained results showed that doing

Heating of polymer substrate by discharge plasma in radiofrequency magnetron sputtering deposition

International Nuclear Information System (INIS)

Sirghi, Lucel; Popa, Gheorghe; Hatanaka, Yoshinori

2006-01-01

The substrate used for the thin film deposition in a radiofrequency magnetron sputtering deposition system is heated by the deposition plasma. This may change drastically the surface properties of the polymer substrates. Deposition of titanium dioxide thin films on polymethyl methacrylate and polycarbonate substrates resulted in buckling of the substrate surfaces. This effect was evaluated by analysis of atomic force microscopy topography images of the deposited films. The amount of energy received by the substrate surface during the film deposition was determined by a thermal probe. Then, the results of the thermal probe measurements were used to compute the surface temperature of the polymer substrate. The computation revealed that the substrate surface temperature depends on the substrate thickness, discharge power and substrate holder temperature. For the case of the TiO 2 film depositions in the radiofrequency magnetron plasma, the computation indicated substrate surface temperature values under the polymer melting temperature. Therefore, the buckling of polymer substrate surface in the deposition plasma may not be regarded as a temperature driven surface instability, but more as an effect of argon ion bombardment

Spectroscopic imaging of self-organization in high power impulse magnetron sputtering plasmas

International Nuclear Information System (INIS)

Andersson, Joakim; Ni, Pavel; Anders, André

2013-01-01

Excitation and ionization conditions in traveling ionization zones of high power impulse magnetron sputtering plasmas were investigated using fast camera imaging through interference filters. The images, taken in end-on and side-on views using light of selected gas and target atom and ion spectral lines, suggest that ionization zones are regions of enhanced densities of electrons, and excited atoms and ions. Excited atoms and ions of the target material (Al) are strongly concentrated near the target surface. Images from the highest excitation energies exhibit the most localized regions, suggesting localized Ohmic heating consistent with double layer formation

A path integral for heavy-quarks in a hot plasma

CERN Document Server

Beraudo, A.; Faccioli, P.; Garberoglio, G.; 10.1016/j.nuclphysa.2010.06.007

2010-01-01

We propose a model for the propagation of a heavy-quark in a hot plasma, to be viewed as a first step towards a full description of the dynamics of heavy quark systems in a quark-gluon plasma, including bound state formation. The heavy quark is treated as a non relativistic particle interacting with a fluctuating field, whose correlator is determined by a hard thermal loop approximation. This approximation, which concerns only the medium in which the heavy quark propagates, is the only one that is made, and it can be improved. The dynamics of the heavy quark is given exactly by a quantum mechanical path integral that is calculated in this paper in the Euclidean space-time using numerical Monte Carlo techniques. The spectral function of the heavy quark in the medium is then reconstructed using a Maximum Entropy Method. The path integral is also evaluated exactly in the case where the mass of the heavy quark is infinite; one then recovers known results concerning the complex optical potential that controls the ...

Sputtering yields and surface chemical modification of tin-doped indium oxide in hydrocarbon-based plasma etching

Energy Technology Data Exchange (ETDEWEB)

Li, Hu; Karahashi, Kazuhiro; Hamaguchi, Satoshi, E-mail: hamaguch@ppl.eng.osaka-u.ac.jp [Center for Atomic and Molecular Technologies, Osaka University, Yamadaoka 2-1, Suita 565-0871 (Japan); Fukasawa, Masanaga; Nagahata, Kazunori; Tatsumi, Tetsuya [Device and Material R& D Group, RDS Platform, Sony Corporation, Kanagawa 243-0014 (Japan)

2015-11-15

Sputtering yields and surface chemical compositions of tin-doped indium oxide (or indium tin oxide, ITO) by CH{sup +}, CH{sub 3}{sup +}, and inert-gas ion (He{sup +}, Ne{sup +}, and Ar{sup +}) incidence have been obtained experimentally with the use of a mass-selected ion beam system and in-situ x-ray photoelectron spectroscopy. It has been found that etching of ITO is chemically enhanced by energetic incidence of hydrocarbon (CH{sub x}{sup +}) ions. At high incident energy incidence, it appears that carbon of incident ions predominantly reduce indium (In) of ITO and the ITO sputtering yields by CH{sup +} and CH{sub 3}{sup +} ions are found to be essentially equal. At lower incident energy (less than 500 eV or so), however, a hydrogen effect on ITO reduction is more pronounced and the ITO surface is more reduced by CH{sub 3}{sup +} ions than CH{sup +} ions. Although the surface is covered more with metallic In by low-energy incident CH{sub 3}{sup +} ions than CH{sup +} ions and metallic In is in general less resistant against physical sputtering than its oxide, the ITO sputtering yield by incident CH{sub 3}{sup +} ions is found to be lower than that by incident CH{sup +} ions in this energy range. A postulation to account for the relation between the observed sputtering yield and reduction of the ITO surface is also presented. The results presented here offer a better understanding of elementary surface reactions observed in reactive ion etching processes of ITO by hydrocarbon plasmas.

Properties of Erbium Doped Hydrogenated Amorphous Carbon Layers Fabricated by Sputtering and Plasma Assisted Chemical Vapor Deposition

Directory of Open Access Journals (Sweden)

V. Prajzler

2008-01-01

Full Text Available We report about properties of carbon layers doped with Er3+ ions fabricated by Plasma Assisted Chemical Vapor Deposition (PACVD and by sputtering on silicon or glass substrates. The structure of the samples was characterized by X-ray diffraction and their composition was determined by Rutherford Backscattering Spectroscopy and Elastic Recoil Detection Analysis. The Absorbance spectrum was taken in the spectral range from 400 nm to 600 nm. Photoluminescence spectra were obtained using two types of Ar laser (λex=514.5 nm, lex=488 nm and also using a semiconductor laser (λex=980 nm. Samples fabricated by magnetron sputtering exhibited typical emission at 1530 nm when pumped at 514.5 nm. 

Hydrodynamic motion of a heavy-ion-beam-heated plasma

International Nuclear Information System (INIS)

Jacoby, J.; Hoffmann, D.H.H.; Mueller, R.W.; Mahrt-Olt, K.; Arnold, R.C.; Schneider, V.; Maruhn, J.

1990-01-01

The first experimental study is reported of a plasma produced by a heavy-ion beam. Relevant parameters for heating with heavy ions are described, temperature and density of the plasma are determined, and the hydrodynamic motion in the target induced by the beam is studied. The measured temperature and the free-electron density are compared with a two-dimensional hydrodynamic-model calculation. In accordance with the model, a radial rarefaction wave reaching the center of the target was observed and the penetration velocity of the ion beam into the xenon-gas target was measured

Plasma focus as an heavy ion source in the problem of heavy ion fusion

International Nuclear Information System (INIS)

Gribkov, V.A.; Dubrovskij, A.V.; Kalachev, N.V.; Krokhin, O.N.; Silin, P.V.; Nikulin, V.Ya.; Cheblukov, Yu.N.

1984-01-01

Results of experiments on the ion flux formation in a plasma focus (PF) to develop a multicharged ion source for thermonuclear facility driver are presented. In plasma focus accelerating section copper ions were injected. Advantages of the suggested method of ion beam formation are demonstrated. Beam emittance equalling < 0.1 cmxmrad is obtained. Plasma focus ion energy exceeds 1 MeV. Plasma focus in combination with a neodymium laser is thought to be a perspective ion source for heavy ion fusion

Thin TiO2 films deposited by implantation and sputtering in RF inductively coupled plasmas

International Nuclear Information System (INIS)

Valencia-Alvarado, R; López-Callejas, R; Barocio, S R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

2012-01-01

The achievement of titanium dioxide (TiO 2 ) thin films in the rutile crystalline phase is reported. The samples result from the implantation of oxygen ions of Ti in argon/oxygen plasma generated by inductively coupled RF at a commercial 13.56 MHz frequency. Simultaneously, a sputtering process is conducted on the titanium target in order to produce TiO 2 thin films in the anatase phase over silicon and glass substrates. Both implantation and sputtering processes shared the same 500 W plasma with the target, polarized between 0 and -3 kV. The substrates were placed between 2 and 3 cm from the target, this distance being found to be determinant of the TiO 2 deposition rate. The rutile phase in the target was obtained at temperatures in the order of 680 degrees C and the anatase (unbiased) one at about 300 degrees C without any auxiliary heating. The crystalline phases were characterized by x ray diffraction and Raman spectroscopy. The morphology and average roughness were established by means of scanning electronic and atomic force microscopy, whereas the reaction products generated during the oxidation process were analyzed by mass spectrometry. Finally, the stoichiometric composition was measured by means of X-ray photoelectron spectroscopy.

Study of sterilization-treatment in pure and N- doped carbon thin films synthesized by inductively coupled plasma assisted pulsed-DC magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Javid, Amjed [Center for Advanced Plasma Surface Technology (CAPST), NU-SKKU Joint Institute for Plasma Nano-Materials (IPNM), Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Department of Textile Processing, National Textile University, Faisalabad 37610 (Pakistan); Kumar, Manish, E-mail: manishk@skku.edu [Center for Advanced Plasma Surface Technology (CAPST), NU-SKKU Joint Institute for Plasma Nano-Materials (IPNM), Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Han, Jeon Geon, E-mail: hanjg@skku.edu [Center for Advanced Plasma Surface Technology (CAPST), NU-SKKU Joint Institute for Plasma Nano-Materials (IPNM), Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

2017-01-15

Highlights: • Pure and N-doped nanocrystallie carbon films are synthesized by ICP assisted pulsed DC plasma process. • ICP power induces the increase in average graphitic crystallite size from 4.86 nm to 6.42 nm. • Beneficial role of ICP source assistance to achieve high sputtering throughput (deposition rate ∼55 nm/min). • Post-sterilization electron-transport study shows N-doped carbon films having promising stability. - Abstract: Electrically-conductive nanocrystalline carbon films, having non-toxic and non-immunogenic characteristics, are promising candidates for reusable medical devices. Here, the pure and N- doped nanocrystalline carbon films are deposited by the assistance of inductively coupled plasma (ICP) in an unbalanced facing target pulsed-DC magnetron sputtering process. Through the optical emission spectroscopy study, the role of ICP assistance and N-doping on the reactive components/radicals during the synthesis is presented. The N-doping enhances the three fold bonding configurations by increasing the ionization and energies of the plasma species. Whereas, the ICP addition increases the plasma density to control the deposition rate and film structure. As a result, sputtering-throughput (deposition rate: 31–55 nm/min), electrical resistivity (4–72 Ωcm) and water contact angle (45.12°–54°) are significantly tailored. Electric transport study across the surface microchannel confirms the superiority of N-doped carbon films for sterilization stability over the undoped carbon films.

Synthesis of ZnO nanorods-Au nanoparticles hybrids via in-situ plasma sputtering-assisted method for simultaneous electrochemical sensing of ascorbic acid and uric acid

Energy Technology Data Exchange (ETDEWEB)

Hou, Chao [College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Liu, Hongying, E-mail: liuhongying@hdu.edu.cn [College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210093 (China); Zhang, Dan; Yang, Chi [Department of Pharmacy, Nantong University, Nantong 226001 (China); Zhang, Mingzhen [College of Life Information Science & Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)

2016-05-05

In this study, ZnO nanorods-Au nanoparticles (ZnO NRs-Au NPs) hybrids were prepared using an in-situ plasma sputtering-assisted method without any template. Characterization results from scanning electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy showed that Au NPs are highly dispersed and tightly anchored on the surface of ZnO NRs. The size and surface coverage of Au NPs were well controlled by plasma sputtering time. Moreover, the hybrids exhibited excellent electrocatalytic properties towards oxidation of ascorbic acid (AA) and uric acid (UA) due to large surface area of Au NPs and ZnO NRs, and thus can be used as electrochemical sensors. Differential pulse voltammetry results showed that AA and UA could be detected simultaneously by ZnO NRs-Au NPs hybrids modified glassy carbon electrode. The linear ranges for AA and UA are 0.1 to 4 mM and 0.01 to 0.4 mM, respectively. The results suggest promising future applications in clinical diagnosis. - Highlights: • ZnO nanorods-Au nanoparticles were synthesized by in-situ plasma sputtering method. • Influence of sputtering time on the formation of Au nanoparticles was studied. • It exhibited a strong electrocatalytic activity toward the oxidation of ascorbic acid and uric acid. • A portable and cheap approach for simultaneous detection of ascorbic acid and uric acid was developed.

Synthesis of ZnO nanorods-Au nanoparticles hybrids via in-situ plasma sputtering-assisted method for simultaneous electrochemical sensing of ascorbic acid and uric acid

International Nuclear Information System (INIS)

Hou, Chao; Liu, Hongying; Zhang, Dan; Yang, Chi; Zhang, Mingzhen

2016-01-01

In this study, ZnO nanorods-Au nanoparticles (ZnO NRs-Au NPs) hybrids were prepared using an in-situ plasma sputtering-assisted method without any template. Characterization results from scanning electron microscopy, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy showed that Au NPs are highly dispersed and tightly anchored on the surface of ZnO NRs. The size and surface coverage of Au NPs were well controlled by plasma sputtering time. Moreover, the hybrids exhibited excellent electrocatalytic properties towards oxidation of ascorbic acid (AA) and uric acid (UA) due to large surface area of Au NPs and ZnO NRs, and thus can be used as electrochemical sensors. Differential pulse voltammetry results showed that AA and UA could be detected simultaneously by ZnO NRs-Au NPs hybrids modified glassy carbon electrode. The linear ranges for AA and UA are 0.1 to 4 mM and 0.01 to 0.4 mM, respectively. The results suggest promising future applications in clinical diagnosis. - Highlights: • ZnO nanorods-Au nanoparticles were synthesized by in-situ plasma sputtering method. • Influence of sputtering time on the formation of Au nanoparticles was studied. • It exhibited a strong electrocatalytic activity toward the oxidation of ascorbic acid and uric acid. • A portable and cheap approach for simultaneous detection of ascorbic acid and uric acid was developed.

Characterization of plasma coated tungsten heavy alloy

International Nuclear Information System (INIS)

Bose, A.; Kapoor, D.; Lankford, J. Jr.; Nicholls, A.E.

1996-01-01

The detrimental environmental impact of Depleted Uranium-based penetrators have led to tremendous development efforts in the area of tungsten heavy alloy based penetrators. One line of investigation involves the coating of tungsten heavy alloys with materials that are prone to shear localization. Plasma spraying of Inconel 718 and 4340 steel have been used to deposit dense coatings on tungsten heavy alloy substrates. The aim of the investigation was to characterize the coating primarily in terms of its microstructure and a special push-out test. The paper describes the results of the push-out tests and analyzes some of the possible failure mechanisms by carrying out microstructural characterization of the failed rings obtained from the push out tests

Distribution of Fe atom density in a dc magnetron sputtering plasma source measured by laser-induced fluorescence imaging spectroscopy

Science.gov (United States)

Shibagaki, K.; Nafarizal, N.; Sasaki, K.; Toyoda, H.; Iwata, S.; Kato, T.; Tsunashima, S.; Sugai, H.

2003-10-01

Magnetron sputtering discharge is widely used as an efficient method for thin film fabrication. In order to achieve the optimized fabrication, understanding of the kinetics in plasmas is essential. In the present work, we measured the density distribution of sputtered Fe atoms using laser-induced fluorescence imaging spectroscopy. A dc magnetron plasma source with a Fe target was used. An area of 20 × 2 mm in front of the target was irradiated by a tunable laser beam having a planar shape. The picture of laser-induced fluorescence on the laser beam was taken using an ICCD camera. In this way, we obtained the two-dimensional image of the Fe atom density. As a result, it has been found that the Fe atom density observed at a distance of several centimeters from the target is higher than that adjacent to the target, when the Ar gas pressure was relatively high. It is suggested from this result that some gas-phase production processes of Fe atoms are available in the plasma. This work has been performed under the 21st Century COE Program by the Ministry of Education, Culture, Sports, Science and Technology in Japan.

High rate reactive sputtering in an opposed cathode closed-field unbalanced magnetron sputtering system

Science.gov (United States)

Sproul, William D.; Rudnik, Paul J.; Graham, Michael E.; Rohde, Suzanne L.

1990-01-01

Attention is given to an opposed cathode sputtering system constructed with the ability to coat parts with a size up to 15 cm in diameter and 30 cm in length. Initial trials with this system revealed very low substrate bias currents. When the AlNiCo magnets in the two opposed cathodes were arranged in a mirrored configuration, the plasma density at the substrate was low, and the substrate bias current density was less than 1 mA/sq cm. If the magnets were arranged in a closed-field configuration where the field lines from one set of magnets were coupled with the other set, the substrate bias current density was as high as 5.7 mA/sq cm when NdFeB magnets were used. In the closed-field configuration, the substrate bias current density was related to the magnetic field strength between the two cathodes and to the sputtering pressure. Hard well-adhered TiN coatings were reactively sputtered in the opposed cathode system in the closed-field configuration, but the mirrored configuration produced films with poor adhesion because of etching problems and low plasma density at the substrate.

Review of the works on plasma-wall interactions in fusion reactors, 1

International Nuclear Information System (INIS)

Sone, Kazuho

1975-09-01

A review is made of the works on sputtering as one of the plasma-wall interactions in thermonuclear fusion devices. The present status and future problems are described mainly in experiments of low-energy light ions such as H + , H 2 + , D + , D 2 + and He + , heavy ions including self-ions, and fast neutrons for polycrystalline metal targets. (auth.)

Formation of large clusters during sputtering of silver

International Nuclear Information System (INIS)

Staudt, C.; Heinrich, R.; Wucher, A.

2000-01-01

We have studied the formation of polyatomic clusters during sputtering of metal surfaces by keV ion bombardment. Both positively charged (secondary cluster ions) and neutral clusters have been detected in a time-of-flight mass spectrometer under otherwise identical experimental conditions, the sputtered neutrals being post-ionized by single photon absorption using a pulsed 157 nm VUV laser beam. Due to the high achievable laser intensity, the photoionization of all clusters could be saturated, thus enabling a quantitative determination of the respective partial sputtering yields. We find that the relative yield distributions of sputtered clusters are strongly correlated with the total sputtering yield in a way that higher yields lead to higher abundances of large clusters. By using heavy projectile ions (Xe + ) in connection with bombarding energies up to 15 keV, we have been able to detect sputtered neutral silver clusters containing up to about 60 atoms. For cluster sizes above 40 atoms, doubly charged species are shown to be produced in the photoionization process with non-negligible efficiency. From a direct comparison of secondary neutral and ion yields, the ionization probability of sputtered clusters is determined as a function of the cluster size. It is demonstrated that even the largest silver clusters are still predominantly sputtered as neutrals

Variables affecting simulated Be sputtering yields

Energy Technology Data Exchange (ETDEWEB)

Björkas, C., E-mail: carolina.bjorkas@helsinki.fi; Nordlund, K.

2013-08-15

Since beryllium is a strong candidate for the main plasma-facing material in future fusion reactors, its sputtering behaviour plays an important role in predicting the reactor’s life-time. Consensus about the actual sputtering yields has not yet been achieved, as observations are influenced by experimental method and/or studied sample. In this work, the beryllium sputtering due to deuterium and beryllium self-bombardment is analyzed using molecular dynamics simulations. The main methodological aspects that influence the outcome, such as flux and fluence of the bombardment, are highlighted, and it is shown that the simulated yields also depend on the sample structure and deuterium content.

Experiments on the interaction of heavy ions with dense plasma at GSI-Darmstadt

International Nuclear Information System (INIS)

Stoeckl, C.; Boine-Frankenheim, O.; Geissel, M.; Roth, M.; Wetzler, H.; Seelig, W.; Iwase, O.; Spiller, P.; Bock, R.; Suess, W.; Hoffmann, D.H.H.

1998-01-01

One of the main objectives of the experimental plasma physics activities at the Gesellschaft fuer Schwerionenforschung (GSI) are the interaction processes of heavy ions with dense ionized matter. Gas-discharge plasma targets were used for energy loss and charge state measurements in a regime of electron density and temperature up to 10 19 cm -3 and 20 eV, respectively. An improved model of the charge exchange processes in fully ionized hydrogen plasma, taking into account multiple excited electronic configurations which subsequently ionize, has removed the discrepancies of previous theoretical descriptions. The energy loss of the ion beam in partially ionized plasmas such as argon was found to agree very well with our simple theoretical model based on the modified Bethe-Bloch theory. A new setup with a 100 J/5 GW Nd-glass laser now provides access to density ranges up to 10 21 cm -3 and temperatures of up to 100 eV. First results of interaction experiments with laser-produced plasma are presented. To fully exploit the experimental possibilities of the new laser-plasma setup both improved charge state detection systems and better plasma diagnostics are indispensable. Present developments and future possibilities in these fields are presented. This paper summarizes the following contributions: Interaction of heavy-ion beams with laser plasma by C. Stoeckl et al. Energy loss of heavy ions in a laser-produced plasma by M. Roth et al. Charge state measurements of heavy ions passing a laser produced plasma with high time resolution by W. Suess et al. Plasma diagnostics for laser-produced plasma by O. Iwase et al. Future possibilities of plasma diagnostics at GSI by M. Geissel et al. (orig.)

Plasma analysis of inductively coupled impulse sputtering of Cu, Ti and Ni

Science.gov (United States)

Loch, D. A. L.; Aranda Gonzalvo, Y.; Ehiasarian, A. P.

2017-06-01

Inductively coupled impulse sputtering (ICIS) is a new development in the field of highly ionised pulsed PVD processes. For ICIS the plasma is generated by an internal inductive coil, replacing the need for a magnetron. To understand the plasma properties, measurements of the current and voltage waveforms at the cathode were conducted. The ion energy distribution functions (IEDFs) were measured by energy resolved MS and plasma chemistry was analysed by OES and then compared to a model. The target was operated in pulsed DC mode and the coil was energised by pulsed RF power, with a duty cycle of 7.5%. At a constant pressure (14 Pa) the set peak RF power was varied from 1000-4000 W. The DC voltage to the target was kept constant at 1900 V. OES measurements have shown a monotonic increase in intensity with increasing power. Excitation and ionisation processes were single step for ICIS of Ti and Ni and multi-step for Cu. The latter exhibited an unexpectedly steep rise in ionisation efficiency with power. The IEDFs measured by MS show the material- and time-dependant plasma potential in the range of 10-30 eV, ideal for increased surface mobility without inducing lattice defects. A lower intensity peak, of high energetic ions, is visible at 170 eV during the pulse.

Secondary ion formation during electronic and nuclear sputtering of germanium

Science.gov (United States)

Breuer, L.; Ernst, P.; Herder, M.; Meinerzhagen, F.; Bender, M.; Severin, D.; Wucher, A.

2018-06-01

Using a time-of-flight mass spectrometer attached to the UNILAC beamline located at the GSI Helmholtz Centre for Heavy Ion Research, we investigate the formation of secondary ions sputtered from a germanium surface under irradiation by swift heavy ions (SHI) such as 5 MeV/u Au by simultaneously recording the mass spectra of the ejected secondary ions and their neutral counterparts. In these experiments, the sputtered neutral material is post-ionized via single photon absorption from a pulsed, intensive VUV laser. After post-ionization, the instrument cannot distinguish between secondary ions and post-ionized neutrals, so that both signals can be directly compared in order to investigate the ionization probability of different sputtered species. In order to facilitate an in-situ comparison with typical nuclear sputtering conditions, the system is also equipped with a conventional rare gas ion source delivering a 5 keV argon ion beam. For a dynamically sputter cleaned surface, it is found that the ionization probability of Ge atoms and Gen clusters ejected under electronic sputtering conditions is by more than an order of magnitude higher than that measured for keV sputtered particles. In addition, the mass spectra obtained under SHI irradiation show prominent signals of GenOm clusters, which are predominantly detected as positive or negative secondary ions. From the m-distribution for a given Ge nuclearity n, one can deduce that the sputtered material must originate from a germanium oxide matrix with approximate GeO stoichiometry, probably due to residual native oxide patches even at the dynamically cleaned surface. The results clearly demonstrate a fundamental difference between the ejection and ionization mechanisms in both cases, which is interpreted in terms of corresponding model calculations.

Pulsed dc self-sustained magnetron sputtering

International Nuclear Information System (INIS)

Wiatrowski, A.; Posadowski, W. M.; Radzimski, Z. J.

2008-01-01

The magnetron sputtering has become one of the commonly used techniques for industrial deposition of thin films and coatings due to its simplicity and reliability. At standard magnetron sputtering conditions (argon pressure of ∼0.5 Pa) inert gas particles (necessary to sustain discharge) are often entrapped in the deposited films. Inert gas contamination can be eliminated during the self-sustained magnetron sputtering (SSS) process, where the presence of the inert gas is not a necessary requirement. Moreover the SSS process that is possible due to the high degree of ionization of the sputtered material also gives a unique condition during the transport of sputtered particles to the substrate. So far it has been shown that the self-sustained mode of magnetron operation can be obtained using dc powering (dc-SSS) only. The main disadvantage of the dc-SSS process is its instability related to random arc formation. In such case the discharge has to be temporarily extinguished to prevent damaging both the magnetron source and power supply. The authors postulate that pulsed powering could protect the SSS process against arcs, similarly to reactive pulsed magnetron deposition processes of insulating thin films. To put this concept into practice, (i) the high enough plasma density has to be achieved and (ii) the type of pulsed powering has to be chosen taking plasma dynamics into account. In this article results of pulsed dc self-sustained magnetron sputtering (pulsed dc-SSS) are presented. The planar magnetron equipped with a 50 mm diameter and 6 mm thick copper target was used during the experiments. The maximum target power was about 11 kW, which corresponded to the target power density of ∼560 W/cm 2 . The magnetron operation was investigated as a function of pulse frequency (20-100 kHz) and pulse duty factor (50%-90%). The discharge (argon) extinction pressure level was determined for these conditions. The plasma emission spectra (400-410 nm range) and deposition

Optical emission and mass spectroscopy of plasma processes in reactive DC pulsed magnetron sputtering of aluminium oxide

Czech Academy of Sciences Publication Activity Database

Novotný, Michal; Bulíř, Jiří; Pokorný, Petr; Bočan, Jiří; Fitl, Přemysl; Lančok, Ján; Musil, Jindřich

2010-01-01

Roč. 12, č. 3 (2010), 697-700 ISSN 1454-4164 R&D Projects: GA AV ČR IAA100100718; GA AV ČR KAN400100653; GA ČR GP202/09/P324 Institutional research plan: CEZ:AV0Z10100522 Keywords : reactive magnetron sputtering * alumina * plasma spectroscopy * mass spectroscopy * optical emission spectroscopy Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.412, year: 2010

Measurement and modeling of plasma parameters in reactive high-power impulse magnetron sputtering of Ti in Ar/O.sub.2./sub. mixtures

Czech Academy of Sciences Publication Activity Database

Čada, Martin; Lundin, D.; Hubička, Zdeněk

2017-01-01

Roč. 121, č. 17 (2017), s. 1-7, č. článku 171913. ISSN 0021-8979 R&D Projects: GA ČR(CZ) GA15-00863S EU Projects: European Commission(XE) 608800 - HIPPOCAMP Institutional support: RVO:68378271 Keywords : reactive sputtering * HiPIMS * Langmuir probe * R-IRM model * plasma density * electron temperature Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.068, year: 2016

Control of composition and crystallinity in hydroxyapatite films deposited by electron cyclotron resonance plasma sputtering

Science.gov (United States)

Akazawa, Housei; Ueno, Yuko

2014-01-01

Hydroxyapatite (HAp) films were deposited by electron cyclotron resonance plasma sputtering under a simultaneous flow of H2O vapor gas. Crystallization during sputter-deposition at elevated temperatures and solid-phase crystallization of amorphous films were compared in terms of film properties. When HAp films were deposited with Ar sputtering gas at temperatures above 460 °C, CaO byproducts precipitated with HAp crystallites. Using Xe instead of Ar resolved the compositional problem, yielding a single HAp phase. Preferentially c-axis-oriented HAp films were obtained at substrate temperatures between 460 and 500 °C and H2O pressures higher than 1×10-2 Pa. The absorption signal of the asymmetric stretching mode of the PO43- unit (ν3) in the Fourier-transform infrared absorption (FT-IR) spectra was the narrowest for films as-crystallized during deposition with Xe, but widest for solid-phase crystallized films. While the symmetric stretching mode of PO43- (ν1) is theoretically IR-inactive, this signal emerged in the FT-IR spectra of solid-phase crystallized films, but was absent for as-crystallized films, indicating superior crystallinity for the latter. The Raman scattering signal corresponding to ν1 PO43- sensitively reflected this crystallinity. The surface hardness of as-crystallized films evaluated by a pencil hardness test was higher than that of solid-phase crystallized films.

Titanium dioxide (TIO2) thin film and plasma properties in RF magnetron sputtering

International Nuclear Information System (INIS)

Ali, Riyaz Ahmad Mohamed; Nayan, Nafarizal

2013-01-01

Lately, titanium dioxide (TiO 2 ) films with anatase crystalline property received numerous attentions as unique material properties. There are wide applications of TiO 2 thin film such as for photocatalytic application in solar cell. In the present study, radio frequency (RF) magnetron sputtering technique has been used to produce high dense, homogeneously controllable film layer at low deposition temperature using titanium (Ti) target. The diameter of the Ti target is 3 inch with fixed discharge power of 400W. Magnetron sputtering plasma has been produced in high purity 99.99% Argon (Ar) and 99.99% Oxygen (O 2 ) environment pressure ranging from 5 to 20 mTorr. The TiO2 were growth on silicon and glass substrates. Substrate temperature during deposition was kept constant at 400°C. The distance between target and substrate holder was maintain at 14 cm with rotation of 10 rotation-per-minutes. Our X-ray diffraction result, shows anatase crystalline successfully formed with characterization peaks of plane (101) at 2θ = 25.28°, plane (202) at 2θ = 48.05° and plane (211) at 2θ = 55.06°. In addition, it is our interest to study the plasma properties and optical spectrum of Ti, Ti+ , O- , ArM and Ar+ in the chamber during the deposition process. Result of emission line intensities, electron density and temperature from optical spectroscope and Langmuir probe will be discuss further during the workshop. This works were supported by Graduate Incentive Scheme of Universiti Tun Hussein Onn Malaysia (UTHM) and Fundamental Research Grant Scheme of Ministry of Higher Education, Malaysia. (author)

Preparation of Ag-containing diamond-like carbon films on the interior surface of tubes by a combined method of plasma source ion implantation and DC sputtering

Science.gov (United States)

Hatada, R.; Flege, S.; Bobrich, A.; Ensinger, W.; Dietz, C.; Baba, K.; Sawase, T.; Watamoto, T.; Matsutani, T.

2014-08-01

Adhesive diamond-like carbon (DLC) films can be prepared by plasma source ion implantation (PSII), which is also suitable for the treatment of the inner surface of a tube. Incorporation of a metal into the DLC film provides a possibility to change the characteristics of the DLC film. One source for the metal is DC sputtering. In this study PSII and DC sputtering were combined to prepare DLC films containing low concentrations of Ag on the interior surfaces of stainless steel tubes. A DLC film was deposited using a C2H4 plasma with the help of an auxiliary electrode inside of the tube. This electrode was then used as a target for the DC sputtering. A mixture of the gases Ar and C2H4 was used to sputter the silver. By changing the gas flow ratios and process time, the resulting Ag content of the films could be varied. Sample characterizations were performed by X-ray photoelectron spectroscopy, secondary ion mass spectrometry, atomic force microscopy and Raman spectroscopy. Additionally, a ball-on-disk test was performed to investigate the tribological properties of the films. The antibacterial activity was determined using Staphylococcus aureus bacteria.

Effect of plasma immersion on crystallinity of V2O5 film grown by dc reactive sputtering at room temperature

International Nuclear Information System (INIS)

Choi, Sun Hee; Kim, Joosun; Yoon, Young Soo

2005-01-01

Vanadium oxide thin films were grown at room temperature by direct current reactive sputtering. To investigate the effect of plasma immersion on the crystallinity of as-grown film, we immersed samples in plasma during the deposition process. X-ray diffraction (XRD) measurements show that as-deposited thin films immersed in plasma are crystalline, whereas those not immersed in the plasma are amorphous. Images taken with scanning electron microscopy show that the surface of films exposed to plasma have a different morphology to the surface of films not exposed to plasma. The Li-intercalation feature of as-deposited films immersed in plasma shows the typical behavior of crystalline vanadium oxide; such behavior is unsuitable for the cathode of thin film batteries (TFBs). These results indicate that direct current plasma promotes the growth of crystalline vanadium oxide films

Probing the Quark Gluon Plasma with Heavy Flavours: recent results from ALICE

CERN Multimedia

CERN. Geneva

2017-01-01

The study of open heavy-flavour physics allows us to investigate the key properties of the Quark-Gluon Plasma (QGP) and the microscopic processes ongoing in the medium produced in heavy-ion collisions at relativistic energies. Heavy quarks are produced in the early stages of heavy-ion collisions and their further production and annihilation rates in the medium are expected to be very small throughout the evolution of the system. Therefore, they serve as penetrating probes that traverse the hot and dense medium, interact with the partonic constituents of the plasma and lose energy. Understanding the interactions of heavy quarks with the medium requires precise measurements over a wide momentum range in heavy-ion collisions, but also in smaller systems like pp collisions, which also test next-to-leading order perturbative QCD calculations, and proton-nucleus collisions, which are sensitive to Cold Nuclear Matter effects (CNM), such as the modification of the parton distribution functions of nuclei, and parton ...

Sputtering properties of tungsten 'fuzzy' surfaces

International Nuclear Information System (INIS)

Nishijima, D.; Baldwin, M.J.; Doerner, R.P.; Yu, J.H.

2011-01-01

Sputtering yields of He-induced W 'fuzzy' surfaces bombarded by Ar have been measured in the linear divertor plasma simulator PISCES-B. It is found that the sputtering yield of a fuzzy surface, Y fuzzy , decreases with increasing fuzzy layer thickness, L, and saturates at ∼10% of that of a smooth surface, Y smooth , at L > 1 μm. The reduction in the sputtering yield is suspected to be due mainly to the porous structure of fuzz, since the ratio, Y fuzzy /Y smooth follows (1 - p fuzz ), where p fuzz is the fuzz porosity. Further, Y fuzzy /Y smooth is observed to increase with incident ion energy, E i . This may be explained by an energy dependent change in the angular distribution of sputtered W atoms, since at lower E i , the angular distribution is observed to become more butterfly-shaped. That is, a larger fraction of sputtered W atoms can line-of-sight deposit/stick onto neighboring fuzz nanostructures for lower E i butterfly distributions, resulting in lower ratio of Y fuzzy /Y smooth .

Spatial survey of a magnetron plasma sputtering system using a Langmuir probe

International Nuclear Information System (INIS)

Field, D.J.; Dew, S.K.; Burrell, R.E.

2002-01-01

A two-dimensional spatial survey is conducted for a magnetron sputtering plasma at two pressures (40 and 5 mTorr) using a Langmuir probe. The plasma density is found to be highest (up to 6.0x10 10 cm -3 ) above the etch region of the cathode, near the magnetic trap. The density drops between the etch regions, near the edges of the cathode and also at distances farther away from the cathode. The floating potential was found to be most negative (down to -12 V) in regions where the highest electron temperatures were observed (up to almost 4 eV) and became less negative (near 0 V) in regions where the electron temperature was lowest (less than 0.5 eV). This complementary trend was consistent in all spatial locations and at both pressures. The plasma potential was found to have very weak dependence, if any, on spatial location and pressure. The relationship between electron transport processes, collision processes and electron temperatures is discussed. Electron energy distribution functions were found to be either Maxwellian or bi-Maxwellian in nature, depending on pressure and spatial location. Maxwellian distributions were found near the magnetic trap or source of the plasma. Bi-Maxwellian distributions were found further away from the source, and it appears they result from Maxwellian distributions bifurcating as they diffuse away from the source. The suitability of the popular models for this bifurcation is discussed

Composite SiOx/fluorocarbon plasma polymer films prepared by r.f. magnetron sputtering of SiO2 and PTFE

Czech Academy of Sciences Publication Activity Database

Pihosh, Y.; Biederman, H.; Slavínská, D.; Kousal, J.; Choukourov, A.; Trchová, Miroslava; Macková, Anna; Boldyryeva, Hanna

2006-01-01

Roč. 81, 1-4 (2006), s. 38-44 ISSN 0042-207X R&D Projects: GA MŠk OC 527.10; GA MŠk ME 553 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z10480505 Keywords : composite films * magnetron * sputtering Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.834, year: 2006

Energy change of a heavy quark in a viscous quark–gluon plasma with fluctuations

International Nuclear Information System (INIS)

Jiang, Bing-feng; Hou, De-fu; Li, Jia-rong

2016-01-01

When a heavy quark travels through the quark–gluon plasma, the polarization and fluctuating chromoelectric fields will be produced simultaneously in the plasma. The drag force due to those fields exerting in return on the moving heavy quark will cause energy change to it. Based on the dielectric functions derived from the viscous chromohydrodynamics, we have studied the collisional energy change of a heavy quark traversing the viscous quark–gluon plasma including fluctuations of chromoelectric field. Numerical results indicate that the chromoelectric field fluctuations lead to an energy gain of the moving heavy quark. Shear viscosity suppresses the fluctuation-induced energy gain and the viscous suppression effect for the charm quark is much more remarkable than that for the bottom quark. While, the fluctuation energy gain is much smaller than the polarization energy loss in magnitude and the net energy change for the heavy quark is at loss.

Ultra relativistic heavy ions collisions or the search for quark-gluon plasmas

International Nuclear Information System (INIS)

Blaizot, J.P.

1985-03-01

This paper reviews some aspects of the physics of ultra-relativistic heavy ion collisions. The qualitative changes expected in the properties of hadronic matter at high temperature and/or large baryon density are described in terms of simple models. We discuss a scenario giving the space-time evolution of a quark-gluon plasma. Finally we address the difficult question of the possible signatures of the formation of a quark-gluon plasma in heavy ion collisions

Plasma effects for heavy ions in implanted silicon detectors

International Nuclear Information System (INIS)

Aiello, S.; Anzalone, A.; Campisi, M.G.; Cardella, G.; Cavallaro, Sl.; Filippo, E. De; Geraci, E.; Geraci, M.; Guazzoni, P.; Manno, M.C. Iacono; Lanzalone, G.; Lanzano, G.; Nigro, S. Lo; Pagano, A.; Papa, M.; Pirrone, S.; Politi, G.; Porto, F.; Rizzo, F.; Sambataro, S.; Sperduto, M.L.; Sutera, C.; Zetta, L.

1999-01-01

Plasma effects for heavy ions in implanted silicon detectors have been investigated for different detector characteristics as a function of type and energy of the detected particles. A new approach is presented and used to reproduce the effect of the plasma delay in the timing performances. The results are in good agreement with the present data and with previous measurements found in the literature

Synthesis and characterization of Al2O3 and SiO2 films with fluoropolymer content using rf-plasma magnetron sputtering technique

International Nuclear Information System (INIS)

Islam, Mohammad; Inal, Osman T.

2008-01-01

Pure and molecularly mixed inorganic films for protection against atomic oxygen in lower earth orbit were prepared using radio-frequency (rf) plasma magnetron sputtering technique. Alumina (Al 2 O 3 ) and silica (SiO 2 ) films with average grain size in the range of 30-80 nm and fully dense or dense columnar structure were synthesized under different conditions of pressure and power. Simultaneous oxide sputtering and plasma polymerization (PP) of hexafluoropropylene (HFP) led to the formation of molecularly mixed films with fluoropolymer content. The degree of plasma polymerization was strongly influenced by total chamber pressure and the argon to HFP molar ratio (n Ar /n M ). An order of magnitude increase in pressure due to argon during codeposition changed the plasma-polymerization mechanism from radical-chain- to radical-radical-type processes. Subsequently, a shift from linear CH 2 group based chain polymerization to highly disordered fluoropolymer content with branching and cross-linking was observed. Fourier transform infrared spectroscopy studies revealed chemical interaction between depositing SiO 2 and PP-HFP through appearance of absorption bands characteristic of Si-F stretching and expansion of SiO 2 network. The relative amount and composition of plasma-polymerized fluoropolymer in such films can be controlled by changing argon to HFP flow ratio, total chamber pressure, and applied power. These films offer great potential for use as protective coatings in aerospace applications

Study of the chemical sputtering in Tore-Supra

International Nuclear Information System (INIS)

Cambe, A.

2002-01-01

The work presented in this thesis focuses on the interactions between energetic particles coming from thermonuclear plasma and the inner components of a fusion machine. This interaction induces two major problems: erosion of the wall, and tritium retention. This report treats the erosion of carbon based materials. The first part is devoted to chemical sputtering, that appears to be the principal erosion mechanism, compared to physical sputtering and radiation enhanced sublimation that both can be limited. Chemical sputtering has been studied in situ in the tokamak Tore-Supra for ohmic and lower hybrid (LH) heated discharges, by means of mass spectrometry and optical spectroscopy. We have shown that it is necessary to take into account both methane and heavier hydrocarbons (C 2 D x and C 3 D y ) in the determination of the chemical sputtering yield. It is found that for the ohmic discharges, the sputtering yield of CD 4 (Y CD4 ) is highly flux (φ) dependent, showing a variation of the form: Y CD4 ∝ φ -0.23 . The experimental study also reveals that an increase of the surface temperature induces an augmentation of Y CD4 . The interpretation and the modelling of the experimental results have been performed with a Monte Carlo code (BBQ. In the second part of this work, we have developed and installed an infrared spectroscopy diagnostic in the 0.8-1.6, μm wavelength range dedicated to the measurement of surface temperature, and the identification of atomic and molecular lines emitted during plasma/wall interactions. In the third part, we present the feasibility study of an in situ tungsten deposition process at low temperature(<80 deg C) in order to suppress the chemical sputtering. This study shows that, with this method call Plasma Assisted Chemical Vapor Deposition (PACVD), we are able to coat the whole inner vessel of a tokamak with 1 μm of tungsten. (author)

Note: Easy-to-maintain electron cyclotron resonance (ECR) plasma sputtering apparatus featuring hybrid waveguide and coaxial cables for microwave delivery

Energy Technology Data Exchange (ETDEWEB)

Akazawa, Housei, E-mail: akazawa.housei@lab.ntt.co.jp [NTT Device Innovation Center, Morinosato Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

2016-06-15

The branched-waveguide electron cyclotron resonance plasma sputtering apparatus places quartz windows for transmitting microwaves into the plasma source not in the line of sight of the target. However, the quartz windows must be replaced after some time of operation. For maintenance, the loop waveguide branching from the T-junction must be dismounted and re-assembled accurately, which is a time-consuming job. We investigated substituting the waveguide branches with two sets of coaxial cables and waveguide/coaxial cable converters to simplify assembly as far as connection and disconnection go. The resulting hybrid system worked well for the purposes of plasma generation and film deposition.

Note: Easy-to-maintain electron cyclotron resonance (ECR) plasma sputtering apparatus featuring hybrid waveguide and coaxial cables for microwave delivery

Science.gov (United States)

Akazawa, Housei

2016-06-01

The branched-waveguide electron cyclotron resonance plasma sputtering apparatus places quartz windows for transmitting microwaves into the plasma source not in the line of sight of the target. However, the quartz windows must be replaced after some time of operation. For maintenance, the loop waveguide branching from the T-junction must be dismounted and re-assembled accurately, which is a time-consuming job. We investigated substituting the waveguide branches with two sets of coaxial cables and waveguide/coaxial cable converters to simplify assembly as far as connection and disconnection go. The resulting hybrid system worked well for the purposes of plasma generation and film deposition.

Photonometers for coating and sputtering machines

Science.gov (United States)

Oupický, P.; Jareš, D.; Václavík, J.; Vápenka, D.

2013-04-01

The concept of photonometers (alternative name of optical monitor of a vacuum deposition process) for coating and sputtering machines is based on photonometers produced by companies like SATIS or HV Dresden. Photometers were developed in the TOPTEC centre and its predecessor VOD (Optical Development Workshop of Institut of Plasma Physics AS CR) for more than 10 years. The article describes current status of the technology and ideas which will be incorporated in next development steps. Hardware and software used on coating machines B63D, VNA600 and sputtering machine UPM810 is presented.

Target surface condition during reactive glow discharge sputtering of copper

International Nuclear Information System (INIS)

Depla, D; Haemers, J; Gryse, R De

2002-01-01

During reactive glow discharge sputtering of copper in an argon/nitrogen plasma, we noticed an abrupt change of the target voltage and the deposition rate when the nitrogen concentration in the plasma exceeds a critical value. To explain this behaviour, the target surface after reactive glow discharge sputtering was examined by x-ray photoelectron spectroscopy (XPS). An experimental arrangement was constructed that allows direct transfer of the glow discharge cathode to the XPS analysis chamber without air exposure. These XPS measurements revealed that several different chemical states of nitrogen are present in the layer that forms on the target surface. The relative concentration of these different states changes when the critical nitrogen concentration in the plasma is exceeded

Arc-discharge and magnetron sputtering combined equipment for nanocomposite coating deposition

International Nuclear Information System (INIS)

Koval, N.N.; Borisov, D.P.; Savostikov, V.M.

2005-01-01

It is known that characteristics of nanocomposite coatings produced by reactive magnetron sputtering undergo an essential influence on the following parameters such as original component composition of targets being sputtered, as well as abundance ratio of such components in the coatings deposited, relative content of inert and reactionary gases in a gas mixture used and a value of operating pressure in a chamber, substrate temperature, and a value of substrate bias potential, determining energy of ionized atoms, ionized atoms flow density, i.e. ion current density on a substrate. The multifactor character of production process of nanocomposite coatings with certain physical and mechanical properties demands a purposeful and complex control on all above-mentioned parameters. To solve such a problem, an arc-discharge and magnetron sputtering combined equipment including a vacuum chamber of approximately ∼ 0.5 m 3 with a built-in low-pressure plasma generator made on the basis of non-self-sustained discharge with a thermal cathode and a planar magnetron combined with two sputtered targets has been created. Construction of such a complex set-up provides both an autonomous mode of operation and simultaneous operation of an arc plasma generator and magnetron sputtering system. Magnetron sputtering of either one or two targets simultaneously is provided as well. An arc plasma generator enables ions current density control on a substrate in a wide range due to discharge current varying from 1 to 100 A. Energy of ions is also being controlled in a wide range by a negative bias potential from 0 to 1000 V applied to a substrate. The wide control range of gas plasma density of a arc discharge of approximately 10 9 -10 11 cm -3 and high uniformity of its distribution over the total volume of an operating chamber (about 15% error with regard to the mean value) provides a purposeful and simultaneous control either of magnetron discharge characteristics (operating pressure of

Tests of a new axial sputtering technique in an ECRIS

International Nuclear Information System (INIS)

Scott, R.; Pardo, R.; Vondrasek, R.

2012-01-01

Axial and radial sputtering techniques have been used over the years to create beams from an ECRIS at multiple accelerator facilities. Operational experience has shown greater beam production when using the radial sputtering method versus axial sputtering. At Argonne National Laboratory, previous work with radial sputtering has demonstrated that the position of the sputter sample relative to the plasma chamber wall influences sample drain current, beam production and charge state distribution. The possibility of the chamber wall acting as a ground plane which influences the sputtering of material has been considered, and an attempt has been made to mimic this possible ground plane effect with a coaxial sample introduced from the injection end. Results of these tests will be shown as well as comparisons of outputs using the two methods. The paper is followed by the associated poster. (authors)

Influence of ion source configuration and its operation parameters on the target sputtering and implantation process.

Science.gov (United States)

Shalnov, K V; Kukhta, V R; Uemura, K; Ito, Y

2012-06-01

In the work, investigation of the features and operation regimes of sputter enhanced ion-plasma source are presented. The source is based on the target sputtering with the dense plasma formed in the crossed electric and magnetic fields. It allows operation with noble or reactive gases at low pressure discharge regimes, and, the resulting ion beam is the mixture of ions from the working gas and sputtering target. Any conductive material, such as metals, alloys, or compounds, can be used as the sputtering target. Effectiveness of target sputtering process with the plasma was investigated dependently on the gun geometry, plasma parameters, and the target bias voltage. With the applied accelerating voltage from 0 to 20 kV, the source can be operated in regimes of thin film deposition, ion-beam mixing, and ion implantation. Multi-component ion beam implantation was applied to α-Fe, which leads to the surface hardness increasing from 2 GPa in the initial condition up to 3.5 GPa in case of combined N(2)-C implantation. Projected range of the implanted elements is up to 20 nm with the implantation energy 20 keV that was obtained with XPS depth profiling.

Thin films of thermoelectric compound Mg2Sn deposited by co-sputtering assisted by multi-dipolar microwave plasma

International Nuclear Information System (INIS)

Le-Quoc, H.; Lacoste, A.; Hlil, E.K.; Bes, A.; Vinh, T. Tan; Fruchart, D.; Skryabina, N.

2011-01-01

Highlights: → Mg 2 Sn thin films deposited by plasma co-sputtering, on silicon and glass substrates. → Formation of nano-grained polycrystalline films on substrates at room temperature. → Structural properties vary with target biasing and target-substrate distance. → Formation of the hexagonal phase of Mg 2 Sn in certain deposition conditions. → Power factor ∼5.0 x 10 -3 W K -2 m -1 for stoichiometric Mg 2 Sn films doped with ∼1 at.% Ag. - Abstract: Magnesium stannide (Mg 2 Sn) thin films doped with Ag intended for thermoelectric applications are deposited on both silicon and glass substrates at room temperature by plasma assisted co-sputtering. Characterization by scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction confirms the formation of fine-grained polycrystalline thin films with thickness of 1-3 μm. Stoichiometry, microstructure and crystal structure of thin films are found to vary with target biasing and the distance from targets to substrate. Measurements of electrical resistivity and Seebeck coefficient at room temperature show the maximum power factor of ∼5.0 x 10 -3 W K -2 m -1 for stoichiometric Mg 2 Sn thin films doped with ∼1 at.% Ag.

Heavy duty plasma spray gun

International Nuclear Information System (INIS)

Irons, G.C.; Klein, J.F.; Lander, R.D.; Thompson, H.C.; Trapani, R.D.

1984-01-01

A heavy duty plasma spray gun for extended industrial service is disclosed. The gun includes a gas distribution member made of a material having a coefficient of expansion different from that of the parts surrounding it. The gas distribution member is forcibly urged by a resilient member such as a coiled spring against a seal so as to assure the plasma gas is introduced into the gun arc in a manner only defined by the gas distribution member. The gun has liquid cooling for the nozzle (anode) and the cathode. Double seals are provided between the coolant and the arc region and a vent is provided between the seals which provides an indication when a seal has failed. Some parts of the gun are electrically isolated from others by an intermediate member which is formed as a sandwich of two rigid metal face pieces and an insulator disposed between them. The metal face pieces provide a rigid body to attach the remaining parts in proper alignment therewith

Copper deposition on fabrics by rf plasma sputtering for medical applications

International Nuclear Information System (INIS)

Segura, G; Guzmán, P; Barrantes, Y; Navarro, G; Asenjo, J; Guadamuz, S; Vargas, VI; Zuñiga, P; Chaves, S; Chaves, J

2015-01-01

The present work is about preparation and characterization of RF sputtered Cu films on cotton by the usage of a Magnetron Sputter Source and 99.995% purity Cu target at room temperature. Cotton fabric samples of 1, 2 and 4 min of sputtering time at discharge pressure of 1×10 −2 Torr and distance between target and sample of 8 cm were used. The main goal was to qualitatively test the antimicrobial action of copper on fabrics. For that purpose, a reference strain of Escherichia Coli ATCC 35218 that were grown in TSA plates was implemented. Results indicated a decrease in the growth of bacteria by contact with Cu; for fabric samples with longer sputtering presented lower development of E. coli colonies. The scope of this research focused on using these new textiles in health field, for example socks can be made with this textile for the treatment of athlete's foot and the use in pajamas, sheets, pillow covers and robes in hospital setting for reducing the spread of microorganisms. (paper)

Contributions of solar-wind induced potential sputtering to the lunar surface erosion rate and it's exosphere

Science.gov (United States)

Alnussirat, S. T.; Barghouty, A. F.; Edmunson, J. E.; Sabra, M. S.; Rickman, D. L.

2018-04-01

Sputtering of lunar regolith by solar-wind protons and heavy ions with kinetic energies of about 1 keV/amu is an important erosive process that affects the lunar surface and exosphere. It plays an important role in changing the chemical composition and thickness of the surface layer, and in introducing material into the exosphere. Kinetic sputtering is well modeled and understood, but understanding of mechanisms of potential sputtering has lagged behind. In this study we differentiate the contributions of potential sputtering from the standard (kinetic) sputtering in changing the chemical composition and erosion rate of the lunar surface. Also we study the contribution of potential sputtering in developing the lunar exosphere. Our results show that potential sputtering enhances the total characteristic sputtering erosion rate by about 44%, and reduces sputtering time scales by the same amount. Potential sputtering also introduces more material into the lunar exosphere.

Origins of Beta Tantalum in Sputtered Coatings

National Research Council Canada - National Science Library

Mulligan, C

2001-01-01

.... Some of the most recent work has attempted to relate the energetics (i.e., atom/ion energy) of the plasma to the alpha right arrow beta transition. It has been shown that the energetics of the plasma can relate to the most crucial sputtering parameters. The most significant feature of the use of plasma energy to explain the alpha right arrow beta transition is that it relates the formation of beta-tantalum to a quantifiable measure.

Photonometers for coating and sputtering machines

Directory of Open Access Journals (Sweden)

Václavík J.

2013-05-01

Full Text Available The concept of photonometers (alternative name of optical monitor of a vacuum deposition process for coating and sputtering machines is based on photonometers produced by companies like SATIS or HV Dresden. Photometers were developed in the TOPTEC centre and its predecessor VOD (Optical Development Workshop of Institut of Plasma Physics AS CR for more than 10 years. The article describes current status of the technology and ideas which will be incorporated in next development steps. Hardware and software used on coating machines B63D, VNA600 and sputtering machine UPM810 is presented.

Sputtering of nano-grains by energetic ions

CERN Document Server

Bringa, E M

2002-01-01

Sputtering from grains with a size of tens of nanometers is important in a number of astrophysical environments having a variety of plasma properties and can have applications in nano-technology. Since energy deposition by incident ions or electrons can create 'hot' regions in a small grain, thermal spike (TS) models have been applied to estimate the sputtering. The excitations produced by a fast ion are often assumed to form a 'hot' cylindrical track. In this paper we use molecular dynamics (MD) calculations to describe the energy transport and sputtering due to the creation of a 'hot' track in a grain with one quarter million atoms. We show the enhancement due to grain size and find that TS models work over a limited range of excitation densities. Discrepancies of several orders of magnitude are found when comparing our MD results for sputtering of small dust grains to those obtained by the astrophysical community using spike models.

Basic electrochemical properties of sputtered gold film electrodes

International Nuclear Information System (INIS)

Libansky, Milan; Zima, Jiri; Barek, Jiri; Reznickova, Alena; Svorcik, Vaclav; Dejmkova, Hana

2017-01-01

Gold nanolayers made by sputtering of pure gold (physical vapour deposition) are commonly used for many biophysical and material applications. However, the use of sputtering method for fabrication of working electrodes for electroanalytical purposes is less common. This paper focuses on the testing and characterization of sputtered working roughened gold nanostructured film electrodes, which fall into category of upcoming desirable new generation of nanostructured gold working electrodes. Gold nanostructured films (80 nm thin) were sputtered onto 50 μm thin PTFE substrates with three different types of treatment: pristine, plasma treated, and plasma treated and subsequently spontaneously grafted with biphenyl-4,4′-dithiol. The characterization of gold nanostructured film electrodes was carried out by examination of the electrode reaction of standard redox probes (ferrocyanide/ferricyanide, hydroquinone/benzoquinone) in different types of supporting electrolytes (BR buffers of various pH, KCl, KNO 3 , H 2 SO 4 ), by exploration of the electrode surface by scanning electron microscopy, by atomic force microscopy accompanied by elementary analysis and contact angle measurements. The testing of electrodes was complemented by an attempt to calculate their real surface areas from Randles-Sevcik equation. All results were compared to conventional bulk gold electrode. The practical applicability of the nanostructured gold electrodes as sensors for the determination of environmental pollutants was verified by voltammetric determination of hydroquinone as a model electrochemically oxidisable organic environmental pollutant.

Heavy quark production form jet conversions in a quark-gluon plasma

Energy Technology Data Exchange (ETDEWEB)

Liu , W.; Fries, R.

2008-05-22

Recently, it has been demonstrated that the chemical composition of jets in heavy ion collisions is significantly altered compared to the jets in the vacuum. This signal can be used to probe the medium formed in nuclear collisions. In this study we investigate the possibility that fast light quarks and gluons can convert to heavy quarks when passing through a quark-gluon plasma. We study the rate of light to heavy jet conversions in a consistent Fokker-Planck framework and investigate their impact on the production of high-p{sub T} charm and bottom quarks at the Relativistic Heavy Ion Collider and the Large Hadron Collider.

Characterization of Niobium Oxide Films Deposited by High Target Utilization Sputter Sources

International Nuclear Information System (INIS)

Chow, R; Ellis, A D; Loomis, G E; Rana, S I

2007-01-01

High quality, refractory metal, oxide coatings are required in a variety of applications such as laser optics, micro-electronic insulating layers, nano-device structures, electro-optic multilayers, sensors and corrosion barriers. A common oxide deposition technique is reactive sputtering because the kinetic mechanism vaporizes almost any solid material in vacuum. Also, the sputtered molecules have higher energies than those generated from thermal evaporation, and so the condensates are smoother and denser than those from thermally-evaporated films. In the typical sputtering system, target erosion is a factor that drives machine availability. In some situations such as nano-layered capacitors, where the device's performance characteristics depends on thick layers, target life becomes a limiting factor on the maximizing device functionality. The keen interest to increase target utilization in sputtering has been addressed in a variety of ways such as target geometry, rotating magnets, and/or shaped magnet arrays. Also, a recent sputtering system has been developed that generates a high density plasma, directs the plasma beam towards the target in a uniform fashion, and erodes the target in a uniform fashion. The purpose of this paper is to characterize and compare niobia films deposited by two types of high target utilization sputtering sources, a rotating magnetron and a high density plasma source. The oxide of interest in this study is niobia because of its high refractive index. The quality of the niobia films were characterized spectroscopically in optical transmission, ellipsometrically, and chemical stoichiometry with X-ray photo-electron spectroscopy. The refractive index, extinction coefficients, Cauchy constants were derived from the ellipsometric modeling. The mechanical properties of coating density and stress are also determined

The Z-pinch as plasma lens for the focusing of heavy ion beams

International Nuclear Information System (INIS)

Elfers, M.

1992-04-01

In the present thesis the influence of a Z-pinch plasma on the shape of heavy-ion beams and the for the understanding of this interaction most important plasma parameters were studied. For this the Z-pinch at the heavy-ion accelerator UNILAC was operated. The magnet field gradients of up to (25 ± 3) T/m occuring in the Z-pinch lead to the plasma-lens effect - the focusing of a charged-particle beam traversing axially the Z-pinch. In this thesis for the first time the focusing of a heavy-ion beam by the azimutal magnetic field of a Z-pinch is described. Different beams with an original diameter of 10 mm were focused. The smallest measured beam diameter amounts to 1 mm half-width. The beam energy amounts to 11.4 MeV/u, which leads at gold as projectile matter to a beam energy of 2.25 GeV. (orig./HSI) [de

Peculiarities in film growth of ferroelectric complex oxides in ion-plasma sputtering

International Nuclear Information System (INIS)

Mukhortov, V.M.; Golovko, Yu.I.; Mukhortov, Vl.M.; Dudkevich, V.P.

1981-01-01

Experimental investigation into the process of complex oxide film growth (using BaTiO 3 and (Ba,Sr)TiO 3 as an example) during ion-plasma sputtering has been carried out. It is shown that neutral excited atoms are knocked out of a ceramic target during its ion bombardment. Removing from the target they loss energy at the expence of collisions and at some distance hsub(cr) the oxidation reaction (BaO, TiO, TiO 2 , SrO) becomes possible. So the ''construction'' material comes in either in the form of atoms or in the form of molecules of simple oxides depending on a distance between cathode and substrate. Two mechanisms of synthesis and crystallization distinguished with dependences of growth rate, elementary cell parameters and other structure characteristics on precipitation temperature correspond to two precipitation mechanisms. Part of re-evaporation and reduction processes is discussed [ru

Electronic sputtering by swift highly charged ions of nitrogen on amorphous carbon

International Nuclear Information System (INIS)

Caron, M.; Haranger, F.; Rothard, H.; Ban d'Etat, B.; Boduch, P.; Clouvas, A.; Potiriadis, C.; Neugebauer, R.; Jalowy, T.

2001-01-01

Electronic sputtering with heavy ions as a function of both electronic energy loss dE/dx and projectile charge state q was studied at the French heavy ion accelerator GANIL. Amorphous carbon (untreated, and sputter-cleaned and subsequently exposed to nitrogen) was irradiated with swift highly charged ions (Z=6-73, q=6-54, energy 6-13 MeV/u) in an ultrahigh vacuum scattering chamber. The fluence dependence of ion-induced electron yields allows to deduce a desorption cross-section σ which varies approximately as σ∼(dE/dx) 1.65 or σ∼q 3.3 for sputter-cleaned amorphous carbon exposed to nitrogen. This q dependence is close to the cubic charge dependence observed for the emission of H + secondary ions which are believed to be emitted from the very surface. However, the power law σ∼(dE/dx) 1.65 , related to the electronic energy loss gives the best empirical description. The dependence on dE/dx is close to a quadratic one thus rather pointing towards a thermal evaporation-like effect

Electronic sputtering of biomolecules and its application in mass spectrometry

International Nuclear Information System (INIS)

Haakansson, P.; Sundqvist, B.U.R.

1989-01-01

In 1974 Macfarlane discovered that fast heavy ions from a 252-Cf source can desorb and ionize molecules from a solid surface. The mass of the molecules was determined by time-of-flight technique. It has been shown that the desorption mechanism is associated with the electron part of the stopping power of the primary ion and the name 'electron sputtering' has been adopted for the phenomenon to distinguish it from the well-known sputtering process with ions of KeV energy. A review of electronic sputtering of biomolecules will be given as well as recent measurements on Langmuir-Blodgett films. One important application of electronic sputtering is in the field of mass spectrometry. With this technique large and nonvolatile molecules can be studied. Particularly adsorption of biomolecules to a nitrocellulose backing has proven to be very useful. Examples will be given of mass spectra from peptides with a molecular weight above 20,000 u. (author)

Thermal spike model interpretation of sputtering yield data for Bi thin films irradiated by MeV {sup 84}Kr{sup 15+} ions

Energy Technology Data Exchange (ETDEWEB)

Mammeri, S. [Centre de Recherche Nucléaire d’Alger, B.P. 399, 02 Bd. Frantz Fanon, Alger-gare, Algiers (Algeria); Ouichaoui, S., E-mail: souichaoui@gmail.com [Université des Sciences et de la Technologie H. Boumediene (USTHB), Faculté de Physique, Laboratoire SNIRM, B.P. 32, El-Alia, 16111 Bab Ezzouar, Algiers (Algeria); Ammi, H. [Centre de Recherche Nucléaire d’Alger, B.P. 399, 02 Bd. Frantz Fanon, Alger-gare, Algiers (Algeria); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P.O. Box 722, Somerset West 7129 (South Africa); Faculty of Health and Wellness Sciences, CPUT, P.O. Box 1906, Bellville 7535 (South Africa); Dib, A. [Centre de Recherche Nucléaire d’Alger, B.P. 399, 02 Bd. Frantz Fanon, Alger-gare, Algiers (Algeria); Msimanga, M. [iThemba LABS, National Research Foundation, P. Bag 11, Wits 2050, Johannesburg (South Africa); Department of Physics, Tshwane University of Technology, P. Bag X680, Pretoria 001 (South Africa)

2015-07-01

A modified thermal spike model initially proposed to account for defect formation in metals within the high heavy ion energy regime is adapted for describing the sputtering of Bi thin films under MeV Kr ions. Surface temperature profiles for both the electronic and atomic subsystems have been carefully evaluated versus the radial distance and time with introducing appropriate values of the Bi target electronic stopping power for multi-charged Kr{sup 15+} heavy ions as well as different target physical proprieties like specific heats and thermal conductivities. Then, the total sputtering yields of the irradiated Bi thin films have been determined from a spatiotemporal integration of the local atomic evaporation rate. Besides, an expected non negligible contribution of elastic nuclear collisions to the Bi target sputtering yields and ion-induced surface effects has also been considered in our calculation. Finally, the latter thermal spike model allowed us to derive numerical sputtering yields in satisfactorily agreement with existing experimental data both over the low and high heavy ion energy regions, respectively, dominated by elastic nuclear collisions and inelastic electronic collisions, in particular with our data taken recently for Bi thin films irradiated by 27.5 MeV Kr{sup 15+} heavy ions. An overall consistency of our model calculation with the predictions of sputtering yield theoretical models within the target nuclear stopping power regime was also pointed out.

Kinetic and Potential Sputtering of Lunar Regolith: The Contribution of the Heavy Highly Charged (Minority) Solar Wind Ions

Science.gov (United States)

Meyer, F. W.; Barghouty, A. F.

2012-01-01

Solar wind sputtering of the lunar surface helps determine the composition of the lunar exosphere and contributes to surface weathering. To date, only the effects of the two dominant solar wind constituents, H+ and He+, have been considered. The heavier, less abundant solar wind constituents have much larger sputtering yields because they have greater mass (kinetic sputtering) and they are highly charged (potential sputtering) Their contribution to total sputtering can therefore be orders of magnitude larger than their relative abundances would suggest

Ferroelectric Plasma Source for Heavy Ion Beam Charge Neutralization

CERN Document Server

Efthimion, Philip; Gilson, Erik P; Grisham, Larry; Logan, B G; Waldron, William; Yu, Simon

2005-01-01

Plasmas are employed as a medium for charge neutralizing heavy ion beams to allow them to focus to a small spot size. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length ~ 0.1-1 m would be suitable. To produce 1 meter plasma, large-volume plasma sources based upon ferroelectric ceramics are being considered. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source will utilize the ferroelectric ceramic BaTiO3 to form metal plasma. The drift tube inner surface of the Neutralized Drift Compression Experiment (NDCX) will be covered with ceramic. High voltage (~ 1-5 kV) is applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. A prototype ferroelectric source 20 cm long produced plasma densities ~ 5x1011 cm-3. The source was integrated into the experiment and successfully charge neutralized the K ion beam. Presently, the 1 meter source ...

Production of Au clusters by plasma gas condensation and their incorporation in oxide matrixes by sputtering

Science.gov (United States)

Figueiredo, N. M.; Serra, R.; Manninen, N. K.; Cavaleiro, A.

2018-05-01

Gold clusters were produced by plasma gas condensation method and studied in great detail for the first time. The influence of argon flow, discharge power applied to the Au target and aggregation chamber length on the size distribution and deposition rate of Au clusters was evaluated. Au clusters with sizes between 5 and 65 nm were deposited with varying deposition rates and size dispersion curves. Nanocomposite Au-TiO2 and Au-Al2O3 coatings were then deposited by alternating sputtering. These coatings were hydrophobic and showed strong colorations due to the surface plasmon resonance effect. By simulating the optical properties of the nanocomposites it was possible to identify each individual contribution to the overall surface plasmon resonance signal. These coatings show great potential to be used as high performance localized surface plasmon resonance sensors or as robust self-cleaning decorative protective layers. The hybrid method used for depositing the nanocomposites offers several advantages over co-sputtering or thermal evaporation processes, since a broader range of particle sizes can be obtained (up to tens of nanometers) without the application of any thermal annealing treatments and the properties of clusters and matrix can be controlled separately.

Very low pressure high power impulse triggered magnetron sputtering

Science.gov (United States)

Anders, Andre; Andersson, Joakim

2013-10-29

A method and apparatus are described for very low pressure high powered magnetron sputtering of a coating onto a substrate. By the method of this invention, both substrate and coating target material are placed into an evacuable chamber, and the chamber pumped to vacuum. Thereafter a series of high impulse voltage pulses are applied to the target. Nearly simultaneously with each pulse, in one embodiment, a small cathodic arc source of the same material as the target is pulsed, triggering a plasma plume proximate to the surface of the target to thereby initiate the magnetron sputtering process. In another embodiment the plasma plume is generated using a pulsed laser aimed to strike an ablation target material positioned near the magnetron target surface.

Characteristics of growth of complex ferroelectric oxide films by plasma-ion sputtering

Science.gov (United States)

Mukhortov, V. M.; Golovko, Yu. I.; Mukhortov, Vl. M.; Dudkevich, V. P.

1981-02-01

An experimental investigation was made of the process of growth of a complex oxide film, such as BaTiO3 or (Ba, Sr)TiO3, by plasma-ion sputtering. It was found that ion bombardment of a ceramic target knocked out neutral excited atoms. These atoms lost energy away from the target by collisions and at a certain critical distance hcr they were capable of oxidation to produce BaO, TiO, TiO2, and SrO. Therefore, depending on the distance between the cathode and the substrate, the “construction” material arrived in the form of atoms or molecules of simple oxides. These two (atomic and molecular) deposition mechanisms corresponded to two mechanisms of synthesis and crystallization differing in respect of the dependences of the growth rate, unit cell parameters, and other structural properties on the deposition temperature. The role of re-evaporation and of oxidation-reduction processes was analyzed.

Deuterium sputtering of Li and Li-O films

Science.gov (United States)

Nelson, Andrew; Buzi, Luxherta; Kaita, Robert; Koel, Bruce

2017-10-01

Lithium wall coatings have been shown to enhance the operational plasma performance of many fusion devices, including NSTX and other tokamaks, by reducing the global wall recycling coefficient. However, pure lithium surfaces are extremely difficult to maintain in experimental fusion devices due to both inevitable oxidation and codeposition from sputtering of hot plasma facing components. Sputtering of thin lithium and lithium oxide films on a molybdenum target by energetic deuterium ion bombardment was studied in laboratory experiments conducted in a surface science apparatus. A Colutron ion source was used to produce a monoenergetic, mass-selected ion beam. Measurements were made under ultrahigh vacuum conditions as a function of surface temperature (90-520 K) using x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and temperature programmed desorption (TPD). Results are compared with computer simulations conducted on a temperature-dependent data-calibrated (TRIM) model.

Atomistic self-sputtering mechanisms of rf breakdown in high-gradient linacs

International Nuclear Information System (INIS)

Insepov, Z.; Norem, J.; Veitzer, S.

2010-01-01

Molecular dynamics (MD) models of sputtering solid and liquid surfaces - including the surfaces charged by interaction with plasma, Coulomb explosion, and Taylor cone formation - were developed. MD simulations of self-sputtering of a crystalline (1 0 0) copper surface by Cu + ions in a wide range of ion energies (50 eV-50 keV) were performed. In order to accommodate energetic ion impacts on a target, a computational model was developed that utilizes MD to simulate rapid atomic collisions in the central impact zone, and a finite-difference method to absorb the energy and shock wave for the collisional processes occurring at a longer time scales. The sputtering yield increases if the surface temperature rises and the surface melts as a result of heat from plasma. Electrostatic charging of the surface under bombardment with plasma ions is another mechanism that can dramatically increase the sputtering yield because it reduces the surface binding energy and the surface tension. An MD model of Taylor cone formation at a sharp tip placed in a high electric field was developed, and the model was used to simulate Taylor cone formation for the first time. Good agreement was obtained between the calculated Taylor cone angle (104.3 deg.) and the experimental one (98.6 deg.). A Coulomb explosion (CE) was proposed as the main surface failure mechanism triggering breakdown, and the dynamics of CE was studied by MD.

Spacecraft-plasma-debris interaction in an ion beam shepherd mission

Science.gov (United States)

Cichocki, Filippo; Merino, Mario; Ahedo, Eduardo

2018-05-01

This paper presents a study of the interaction between a spacecraft, a plasma thruster plume and a free floating object, in the context of an active space debris removal mission based on the ion beam shepherd concept. The analysis is performed with the EP2PLUS hybrid code and includes the evaluation of the transferred force and torque to the target debris, its surface sputtering due to the impinging hypersonic ions, and the equivalent electric circuit of the spacecraft-plasma-debris interaction. The electric potential difference that builds up between the spacecraft and the debris, the ion backscattering and the backsputtering contamination of the shepherd satellite are evaluated for a nominal scenario. A sensitivity analysis is carried out to evaluate quantitatively the effects of electron thermodynamics, ambient plasma, heavy species collisions, and debris position.

Emissions from heavy current carrying high density plasma and their diagnostics

International Nuclear Information System (INIS)

Hirano, Katsumi

1987-06-01

Workshop on ''Emissions from heavy current carrying high density plasma and diagnostics'' was held at Institute of Plasma Physics, Nagoya University on 3. and 4. December 1986 under a collaborating research Program. The workshop was attended by 43 researchers from 19 labolatories. A total of 22 papers were submitted and are presented in these proceedings. The largest group of papers was that on soft X-ray emission. It seems this topic is a foremost interest for groups which engaged in research of the Z pinch and the plasma focus. A variety of problems in pinched dense plasmas, namely spectroscopy, diagnostics, pinch dynamics, and related engineering aspects were also discussed. (author)

Particle porosity at plasma are spraying of metals

International Nuclear Information System (INIS)

Petrunichev, V.A.; Koroleva, E.B.; Pushilin, N.P.

1985-01-01

Quantitative dependences of porosity and character of pore distribution in particles of different materials on particle size and composition of atmosphere in a working chamber are studied experimentally as applied to the process of plasma wire sputtering. Wires 1.2 mm in diameter made of tungsten, molybdenum, Kh20N80 alloy, and zirconium served as sputtering materials. It is shown that pore size and character of their distribution in particles of powders obtained by the method of plasma wire sputtering are dependent on sizes of forming particles and determined by conditions of their cooling. Intensive porosity formation is characteristic of wire sputtering in argon plasma with nitrogen additions, but there are critical values of nitrogen concentration in plasma, above which intensive porosity formation in forming particles stops

High power pulsed magnetron sputtering of transparent conducting oxides

International Nuclear Information System (INIS)

Sittinger, V.; Ruske, F.; Werner, W.; Jacobs, C.; Szyszka, B.; Christie, D.J.

2008-01-01

High power pulsed magnetron sputtering (HPPMS) has been used in order to study the deposition of transparent conducting oxides. We summarize the studies carried out on different materials (indium tin oxide-ITO and aluminium-doped zinc oxide-AZO) using rather different technological approaches, namely sputtering of ceramic targets and reactive sputtering. For the deposition of AZO reactive HPPMS for metallic targets has been used. A feedback control loop has been implemented in order to stabilize the discharge at any given setpoint on the hysteresis curve. The hysteresis was also found to have a rather untypical form. Reactive HPPMS was found to be a promising tool for obtaining high quality films of low total thickness. In the case of ITO deposition a ceramic target has been used. The process has been characterized in terms of its plasma emission and increasing indium ionization was found for higher peak power densities. The properties of the deposited films were compared to DC sputtered films. While for DC sputtering the choice of oxygen addition and shieldings is crucial for determining surface morphology and resistivity, in HPPMS sputtering peak power density has been found to be a good parameter for influencing the crystal structure. The morphologies obtained differ strongly from those seen in DC sputtering. At high power densities films with low surface roughness and excellent resistivity could be deposited without the use of shieldings

Measurement of heavy metals by means of a plasma-assisted method

International Nuclear Information System (INIS)

Hernberg, R.; Haeyrinen, V.; Oikari, R.

1995-01-01

The plasma-assisted measuring device for on-line measurement of alkali metal concentrations in pressurised processes, which has been developed in the Laboratory, will be further developed to provide for simultaneous measurement of heavy metal concentrations. (author)

Results of Monte-Carlo studies on backscattering and sputtering from 'pocket' and 'finned' structures

International Nuclear Information System (INIS)

Brown, K.P.

1978-01-01

A Monte-Carlo computer program which has been developed for studying backscattering and sputtering processes involving high energy particles in complex vacuum structures has been used to show that useful reductions in backscattering and sputtering can be achieved by pocketing or finning the wall surfaces of plasma containment vessels. (author)

Observation of self-sputtering in energetic condensation of metal ions

International Nuclear Information System (INIS)

Anders, Andre

2004-01-01

The condensation of energetic metal ions on a surface may cause self-sputtering even in the absence of substrate bias. Charge-state-averaged self-sputtering yields were determined for both zirconium and gold ions generated by a cathodic vacuum arc. Films were deposited on differently biased substrates exposed to streaming Zr and Au vacuum arc plasma. The self-sputtering yields for both metals were estimated to be about 0.05 in the absence of bias, and exceeding 0.5 when bias reached-50 V. These surprisingly high values can be reconciled with binary collision theory and molecular dynamics calculations taking high the kinetic and potential energy of vacuum arc ions into account

Sputtering of amorphous carbon layers studied by laser induced fluorescence

International Nuclear Information System (INIS)

Pasch, E.

1992-07-01

In order to minimize the radiation losses, it is desirable to keep the plasmas in nuclear fusion devices free of high-Z-impurities. Therefore, the walls of TEXTOR and other tokamaks are covered with thin layers of amorphous carbon layers (a-C:H) or amorphous carbon/boron layers (a-C/B:H). The sputtering behaviour of these layers has been studied under bombardment by Ar + ions with energies of 1.5 keV and current densities of a few mA/cm 2 . Investigations of these coatings were carried out with the object to measure the velocity distribution of the sputtered atoms and the sputtered yields by laser induced fluorescence in the vacuum ultraviolet. (orig.)

RF plasma source for heavy ion beam charge neutralization

International Nuclear Information System (INIS)

Efthimion, Philip C.; Gilson, Erik; Grisham, Larry; Davidson, Ronald C.; Yu, Simon S.; Logan, B. Grant

2003-01-01

Highly ionized plasmas are being used as a medium for charge neutralizing heavy ion beams in order to focus the ion beam to a small spot size. A radio frequency (RF) plasma source has been built at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization with plasma. The goal is to operate the source at pressures ∼ 10 -5 Torr at full ionization. The initial operation of the source has been at pressures of 10 -4 -10 -1 Torr and electron densities in the range of 10 8 -10 11 cm -3 . Recently, pulsed operation of the source has enabled operation at pressures in the 10 -6 Torr range with densities of 10 11 cm -3 . Near 100% ionization has been achieved. The source has been integrated with the NTX facility and experiments have begun

Fully nonlinear heavy ion-acoustic solitary waves in astrophysical degenerate relativistic quantum plasmas

Science.gov (United States)

Sultana, S.; Schlickeiser, R.

2018-05-01

Fully nonlinear features of heavy ion-acoustic solitary waves (HIASWs) have been investigated in an astrophysical degenerate relativistic quantum plasma (ADRQP) containing relativistically degenerate electrons and non-relativistically degenerate light ion species, and non-degenerate heavy ion species. The pseudo-energy balance equation is derived from the fluid dynamical equations by adopting the well-known Sagdeev-potential approach, and the properties of arbitrary amplitude HIASWs are examined. The small amplitude limit for the propagation of HIASWs is also recovered. The basic features (width, amplitude, polarity, critical Mach number, speed, etc.) of HIASWs are found to be significantly modified by the relativistic effect of the electron species, and also by the variation of the number density of electron, light ion, and heavy ion species. The basic properties of HIASWs, that may propagated in some realistic astrophysical plasma systems (e.g., in white dwarfs), are briefly discussed.

Low resistivity of Ni–Al co-doped ZnO thin films deposited by DC magnetron sputtering at low sputtering power

Energy Technology Data Exchange (ETDEWEB)

Lee, JongWoo [Department of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Hui, K.N. [Department of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Hui, K.S., E-mail: kshui@hanyang.ac.kr [Department of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Cho, Y.R., E-mail: yescho@pusan.ac.kr [Department of Materials Science and Engineering, Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of); Chun, Ho-Hwan [Global Core Research Center for Ships and Offshore Plants (GCRC-SOP), Pusan National University, San 30 Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)

2014-02-28

Ni–Al co-doped ZnO (NiAl:ZnO) thin films were deposited on glass substrates by DC magnetron sputtering in Ar using a single ceramic, spark-plasma-sintered target with 2 wt% Al and 5 wt% Ni. The effects of the sputtering power and gas pressure on the NiAl:ZnO films were studied. The structural, electrical, and optical properties of the films were characterized by X-ray diffraction, field emission scanning electron microscopy, Hall effect measurements and UV–vis transmission spectroscopy. As the sputtering power and gas pressure increased, the crystallinity, electrical properties and optical band gap of the films were improved. The NiAl:ZnO film deposited at 40 W at 6.0 mTorr had the strongest (0 0 2) XRD peak and the lowest resistivity of approximately 2.19 × 10{sup −3} Ω cm with an optical transmittance of 90%.

Study of carbon impurity generation by chemical sputtering in JT-60U

International Nuclear Information System (INIS)

Higashijima, S.; Kubo, H.; Sugie, T.; Shimizu, K.; Asakura, N.; Itami, K.; Hosogane, N.; Sakasai, A.; Konoshima, S.; Sakurai, S.; Takenaga, H.

1997-01-01

CD/CH-band intensities emitted from hydrocarbon molecules have been measured in the divertor region of JT-60U and the chemical sputtering yield of methane was estimated as a function of the surface temperature and the deuterium ion flux. The chemical sputtering yield increases with the surface temperature and decreases with increasing ion flux density in the L-mode plasmas. The B 4 C converted CFC tiles are installed in JT-60U and it is found that the chemical sputtering of B 4 C converted CFC tiles is suppressed in comparison to normal CFC tiles. (orig.)

Niobium-based catalysts prepared by reactive radio-frequency magnetron sputtering and arc plasma methods as non-noble metal cathode catalysts for polymer electrolyte fuel cells

International Nuclear Information System (INIS)

Ohnishi, Ryohji; Katayama, Masao; Takanabe, Kazuhiro; Kubota, Jun; Domen, Kazunari

2010-01-01

Two vacuum methods, reactive radio-frequency (RF) magnetron sputtering and arc plasma deposition, were used to prepare niobium-based catalysts for an oxygen reduction reaction (ORR) as non-noble metal cathodes for polymer electrode fuel cells (PEFCs). Thin films with various N and O contents, denoted as NbO x and Nb-O-N, were prepared on glassy carbon plates by RF magnetron sputtering with controlled partial pressures of oxygen and nitrogen. Electrochemical measurements indicated that the introduction of the nitrogen species into the thin film resulted in improved ORR activity compared to the oxide-only film. Using an arc plasma method, niobium was deposited on highly oriented pyrolytic graphite (HOPG) substrates, and the sub-nanoscale surface morphology of the deposited particles was investigated using scanning tunneling microscopy (STM). To prepare practical cathode catalysts, niobium was deposited on carbon black (CB) powders by arc plasma method. STM and transmission electron microscopy observations of samples on HOPG and CB indicated that the prepared catalysts were highly dispersed at the atomic level. The onset potential of oxygen reduction on Nb-O-N/CB was 0.86 V vs. a reversible hydrogen electrode, and the apparent current density was drastically improved by the introduction of nitrogen.

Ion-induced sputtering

International Nuclear Information System (INIS)

Yamamura, Yasumichi; Shimizu, Ryuichi; Shimizu, Hazime; Ito, Noriaki.

1983-01-01

The research on ion-induced sputtering has been continued for a long time, since a hundred or more years ago. However, it was only in 1969 by Sigmund that the sputtering phenomena were theoretically arranged into the present form. The reason why the importance of sputtering phenomena have been given a new look recently is the application over wide range. This paper is a review centering around the mechanism of causing sputtering and its characteristics. Sputtering is such a phenomenon that the atoms in the vicinity of a solid surface are emitted into vacuum by receiving a part of ion energy, or in other words, it is a kind of irradiation damage in the vicinity of a solid surface. In this meaning, it can be considered that the sputtering based on the ions located on the clean surface of a single element metal is simple, and has already been basically understood. On the contrary, the phenomena can not be considered to be fully understood in the case of alloys and compounds, because these surface conditions under irradiation are not always clear due to segregation and others. In the paper, the physical of sputtering, single element sputtering, the sputtering in alloys and compounds, and the behaviour of emitted particles are explained. Finally, some recent topics of the sputtering measurement by laser resonant excitation, the sputtering by electron excitation, chemical sputtering, and the sputtering in nuclear fusion reactors are described. (Wakatsuki, Y.)

Means for obtaining a metal ion beam from a heavy-ion cyclotron source

Science.gov (United States)

Hudson, E.D.; Mallory, M.L.

1975-08-01

A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

Investigation of the energy loss and the charge state of high energy heavy ions in a hydrogen plasma

International Nuclear Information System (INIS)

Dietrich, K.G.

1991-07-01

For heavy ions with energy of 1.4 to 5.9 MeV/u the energy loss and charge state after transmission through a totally ionized hydrogen plasma are investigated. Plasma target was a Z-pinch device incorporated in the beam optics of the accelerator by a pumping system. In the 20 cm long pinch hydrogen plasmas with densities up to 1.5x10 19 cm -3 and temperatures above 5 eV are produced, with ionization efficiency higher than 99%. The ions pass the plasma on the symmetry axis of the plasma column through small apertures in the electrodes. The energy loss was measured by time-of-flight method, the plasma density by interferometry along the pinch axis. For the first time the ion charge after transmission through the plasma has been determined by a charge spectrometer being a combination of a dipole magnet and a position sensitive detector with high time resolution. A growth of the average charge of heavy ions in plasma higher than the equilibrium charge in cold gas was discovered, caused by a reduction of electron capture by fast heavy ions in ionized matter. The electron loss rates in plasma and cold gas are equal. (orig./AH) [de

Cold plasmas

International Nuclear Information System (INIS)

Franz, G.

1990-01-01

This textbook discusses the following topics: Phenomenological description of a direct current glow discharge; the plasma (temperature distribution and measurement, potential variation, electron energy distribution function, charge neutralization, wall potentials, plasma oscillations); Production of charge carriers (ions, electrons, ionization in the cathode zone, negative glowing zone, Faraday dark space, positive column, anode zone, hollow cathode discharges); RF-discharges (charge carrier production, RF-Shields, scattering mechanisms); Sputtering (ion-surface interaction, kinetics, sputtering yield and energy distribution, systems and conditions, film formation and stresses, contamination, bias techniques, multicomponent film deposition, cohesion, magnetrons, triode systems, plasma enhanced chemical vapor deposition); Dry etching (sputter etching, reactive etching, topography, process control, quantitative investigations); Etching mechanisms (etching of Si and SiO 2 with CF 4 , of III/V-compound-semiconductors, combination of isotrope and anisotrope etching methods, surface cleaning); ion beam systems (applications, etching); Dyclotron-resonance-systems (electron cyclotron resonance systems, whistler-sources and 'resonant inductive plasma etching'); Appendix (electron energy distribution functions, Bohm's transition zone, plasma oscillations, scattering cross sections and mean free path, metastable states, Child-Langmuir-Schottky equation, loss mechanisms, charge carrier distribution in the positive column, breakdown at high frequencies, motion in a magnetic field, skin depth of an electric field for a HF-discharge, whistler waves, dispersion relations for plane wave propagation). (orig.) With 138 figs

Experimental investigations of plasma lens focusing and plasma channel transport of heavy ion beams

International Nuclear Information System (INIS)

Tauschwitz, T.; Yu, S.S.; Eylon, S.; Reginato, L.; Leemans, W.; Rasmussen, J.O.; Bangerter, R.O.

1995-04-01

Final focusing of ion beams and propagation in a reactor chamber are crucial questions for heavy ion beam driven Fusion. An alternative solution to ballistic quadrupole focusing, as it is proposed in most reactor studies today, is the utilization of the magnetic field produced by a high current plasma discharge. This plasma lens focusing concept relaxes the requirements for low emittance and energy spread of the driver beam significantly and allows to separate the issues of focusing, which can be accomplished outside the reactor chamber, and of beam transport inside the reactor. For focusing a tapered wall-stabilized discharge is proposed, a concept successfully demonstrated at GSI, Germany. For beam transport a laser pre-ionized channel can be used

Long plasma source for heavy ion beam charge neutralization

International Nuclear Information System (INIS)

Efthimion, Philip C.; Gilson, Erik P.; Grisham, Larry; Davidson, Ronald C.; Grant Logan, Larry B.; Seidl, Peter A.; Waldron, William

2009-01-01

Plasmas are a source of unbound electrons for charge neutralizing intense heavy ion beams to focus them to a small spot size and compress their axial length. The plasma source should operate at low neutral pressures and without strong externally applied fields. To produce long plasma columns, sources based upon ferroelectric ceramics with large dielectric coefficients have been developed. The source utilizes the ferroelectric ceramic BaTiO 3 to form metal plasma. The drift tube inner surface of the Neutralized Drift Compression Experiment (NDCX) is covered with ceramic material. High voltage (∼8 kV) is applied between the drift tube and the front surface of the ceramics. A BaTiO 3 source comprised of five 20-cm-long sources has been tested and characterized, producing relatively uniform plasma in the 5x10 10 cm -3 density range. The source was integrated into the NDCX device for charge neutralization and beam compression experiments, and yielded current compression ratios ∼120. Present research is developing multi-meter-long and higher density sources to support beam compression experiments for high-energy-density physics applications.

Composite SiO.sub.x./sub./hydrocarbon plasma polymer films prepared by RF magnetron sputtering of SiO.sub.2./sub. and polyethylene or polypropylene

Czech Academy of Sciences Publication Activity Database

Pihosh, Y.; Biederman, H.; Slavínská, D.; Kousal, J.; Choukourov, A.; Trchová, Miroslava; Macková, Anna; Boldyryeva, Hanna

2006-01-01

Roč. 81, 1-4 (2006), s. 32-37 ISSN 0042-207X R&D Projects: GA MŠk 1P05ME754 Institutional research plan: CEZ:AV0Z40500505; CEZ:AV0Z10480505 Keywords : composite films * magnetron * sputtering Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.834, year: 2006

Sputtered catalysts

International Nuclear Information System (INIS)

Tyerman, W.J.R.

1978-01-01

A method is described for preparing a supported catalyst by a sputtering process. A material that is catalytic, or which is a component of a catalytic system, is sputtered on to the surface of refractory oxide particles that are compatible with the sputtered material and the sputtered particles are consolidated into aggregate form. The oxide particles before sputtering should have a diameter in the range 1000A to 50μ and a porosity less than 0.4 ml/g, and may comprise MgO, Al 2 O 3 or SiO 2 or mixtures of these oxides, including hydraulic cement. The particles may possess catalytic activity by themselves or in combination with the catalytic material deposited on them. Sputtering may be effected epitaxially and consolidation may be effected by compaction pelleting, extrusion or spray drying of a slurry. Examples of the use of such catalysts are given. (U.K.)

Carbon and tungsten effect on characteristics of sputtered and re-deposited beryllium target layers under deuteron bombardment

International Nuclear Information System (INIS)

Danelyan, L.S.; Gureev, V.M.; Elistratov, N.G.

2004-01-01

The behavior of the plasma facing Be-elements in the International Thermonuclear Experimental Reactor ITER will be affected by the re-deposition of other eroded plasma facing materials. The effect of carbon- and tungsten-additions on the microstructure, chemical composition and hydrogen isotope accumulation in the sputtered and re-deposited layers of beryllium TGP-56 at its interaction with 200 - 300 eV hydrogen isotope ions was studied in the MAGRAS facility equipped with a magnetron sputtering system. (author)

Use of spectra from foil-excited heavy-ion beams to interpret radiation from plasmas

International Nuclear Information System (INIS)

Johnson, B.M.

1978-01-01

Spectra from foil-excited heavy ion beams can be used to investigate the relative abundance and charge state composition of heavy metal contaminants which cause severe radiative energy losses in tokamak-produced plasmas. The degree of ionization of these metals in the tokamak plasma is not well known because of uncertainties in ionization and recombination rates and particle confinement times. Only a few stages of ionization are typically prominent in foil-excited spectra, however, and both the most probable charge state and distribution width are well known. Highly ionized heavy ions (e.g., Ti, Mo, W and Au) which span the range of charge states found in present tokamaks were produced by passing beams from the Brookhaven MP tandem Van de Graaff accelerator facility through 20 μg/cm 2 carbon stripping foils. EUV radiation was recorded with a grazing incidence spectrometer. Comparisons of the beam-foil spectra with radiation from plasmas, and recent direct determinations of atomic oscillator strengths for principal resonance lines of such highly ionized species as Li-like iron (Fe 23+ ), Na-like bromine (Br 24+ ), and Cu-like iodine (I 24+ ) are discussed

Interaction of heavy ions beams with hot and dense plasmas. Application to inertial fusion

International Nuclear Information System (INIS)

Maynard, Gilles

1987-01-01

The subject of this work is the variation with time, on one of the energy and charge state of an heavy ion beam which through a plasma, and on another side, of a target used in ion inertial confinement fusion. We take in account projectile excitation, and higher order corrections to the Born stopping power formula are calculated. Comparison with experimental results in gas and solid are good. In hot plasma case, non-equilibrium charge states are described. We present an hydrodynamic simulation code of one dimension and three temperatures. We show that the shortening of the heavy ions beams with temperature reinforces the radiative transfer importance. (author) [fr

Sputtering gases and pressure effects on the microstructure, magnetic properties and recording performance of TbFeCo films

International Nuclear Information System (INIS)

Murakami, Motoyoshi; Birukawa, Masahiro

2008-01-01

The MsHc value is considered to be a key factor in high-density recording, and controlling the microstructure on the magnetic underlayer was found to be an effective way of increasing the MsHc of the amorphous TbFeCo magneto-optical (MO) medium. In this paper, we investigate the TbFeCo film's magnetic properties and the effects on the microcolumnar structure, which depends on the sputtering conditions of using various sputtering gases including Ar, Kr, and Xe, and the recording characteristics of TbFeCo memory layers. With heavy sputtering gases such as Kr or Xe, the columnar structure can be prepared in a TbFeCo film at a pressure lower than 1.0 Pa. The columnar structure of a recording layer can be effectively formed thanks to the effects of the magnetic underlayer, which has a fine surface even in the sputtering process in which Xe gas is used. The above applies to the sputtering process in which Ar gas is used. Also, when Xe gas is used in the sputtering process, coercivity Hc is increased through the formation of a well-segregated microcolumnar structure built on domain wall pinning sites, and we obtain a large MsHc and a high squareness ratio of the Kerr-hysteresis loop. Our results indicate that processing a TbFeCo film with heavy sputtering gases is suitable for tiny mark stability because the temperature gradient of Hc is increased. The objective of the low-pressure sputtering process using Xe gas to produce the columnar structure is to achieve ultra-high-density recording with tiny mark stability in the TbFeCo medium. This has been confirmed with magnetic force microscope (MFM) images of stable tiny marks recorded on TbFeCo film

DC Magnetron sputtering of Y-Ba-Cu-O thin films

International Nuclear Information System (INIS)

Larsson, Gunnar.

1990-01-01

I have been studying dc magnetron sputtering of thin film YBa 2 Cu 3 O 6+x , one of the recently discovered high- temperatures superconductors. In the introduction a brief review of the subjects sputtering and superconductivity is given. Since partial pressure measurements, especially for oxygen, have been important in the work I include a short description of the operating principles of mass spectroscopy. Experimental results in addition to what is given in the papers concerning plasma are presented in an appendix at the end of the introduction. (au)

Vortex trapping in Pb-alloy Josephson junctions induced by strong sputtering of the base electrode

International Nuclear Information System (INIS)

Wada, M.; Nakano, J.; Yanagawa, F.

1985-01-01

It is observed that strong rf sputtering of the Pb-alloy base electrodes causes the junctions to trap magnetic vortices and thus induces Josephson current (I/sub J/) suppression. Trapping begins to occur when the rf sputtering that removes the native thermal oxide on the base electrode is carried out prior to rf plasma oxidation. Observed large I/sub J/ suppression is presumably induced by the concentration of vortices into the sputtered area upon cooling the sample below the transition temperature. This suggests a new method of the circumvention of the vortex trapping by strongly rf sputtering the areas of the electrode other than the junction areas

On contribution of energetic and heavy ions to the plasma pressure: Storm Sept 27 - Oct 4, 2002

Science.gov (United States)

Kronberg, E. A.; Mouikis, C.; Kistler, L. M.; Dandouras, I. S.; Daly, P. W.; Welling, D. T.; Grigorenko, E. E.

2015-12-01

Contribution of the energetic ions (>> 40 keV) and of heavy ions into the total plasma pressure is often neglected. In this study we evaluate the contribution of these components for the storm observed from September 27 to October 4 in 2002. The thermal component of the pressure for the protons, helium and oxygen at 0--40 keV/q is measured by the Cluster/CIS/CODIF sensor. The contribution of the energetic ions at energies >> 40 keV is calculated from the Cluster/RAPID/IIMS observations. The results show that before the storm has initiated, the contribution of the energetic ions in to the total pressure is indeed negligible in the tail plasma sheet, less than ˜1%. However, with the storm development contribution of the energetic part becomes significant, up to ˜30%, towards the recovery phase and cannot be neglected. Heavy ions contribute to the 27% of the total pressure and half of them are energetic. The contribution of energetic ions to the pressure of the ring current (L≃5) is significant. The heavy ions play a dominant role in the plasma pressure, about 62% during the main phase of the magnetic storm. Half of them are energetic ions. The SWMF/BATS-R-US MHD model underestimates the contribution of the energetic and heavy ions in to the ion distribution in the magnetotail plasma sheet and the ring current. The ring current plasma pressure distorts the terrestrial internal magnetic field and defines magnetic storm. Therefore, it is essential to take in to account the contribution of the energetic and heavy ions.

Heavy metals behavior during thermal plasma vitrification of incineration residues

International Nuclear Information System (INIS)

Cerqueira, N.; Vandensteendam, C.; Baronnet, J.M.

2005-01-01

In the developed world, incineration of wastes is widely and increasingly practiced. Worldwide, a total of approximately 100 millions of tons of municipal solid waste (MSW) material is incinerated annually. Incineration of one ton of MSW leads to the formation of 30 to 50 kg of fly ash, depending on the type of incinerator. The waste disposal of these dusts already causes great problems today; they are of low bulk density, they contain high concentrations of hazardous water-soluble heavy metal compounds, organohalogen compounds (dioxines, furanes), sulfur, and chlorinated compounds. Thermal processes, based mainly on electrical arc processes, show great promise: the residues are melted at high temperature and converted in a relatively inert glass. A few tens of plants, essentially in Japan and Taiwan, have been in industrial operation for a few years. To be authorized to be dumped in a common landfill, the glassy product has to satisfy the leaching test procedure to ensure long-term durability. But to satisfy the regulation to be reused, for example as a nonhazardous standard material in road building, the glassy product would probably include contents in some heavy metals lower than critical limits. So today, there are two alternatives: the first one is to improve the heavy toxic metals evaporation to get a 'light' glassy product and to recycle separately the said separated metals; the second is on the contrary to improve the incorporation of a maximum of heavy metals into the vitreous silicate matrix. Whatever, it is highly required to control, in situ and in real time, volatility of these metals during ash melting under electrical arc. The objective of this work was to reach basic data about metals volatility under the plasma column of an electrical arc transferred on the melt: an experiment has been designed to examine the effects of processing conditions, such as melt temperature, melt composition, and furnace atmosphere, upon volatilization and glassy slag

Radio frequency plasma excitation

International Nuclear Information System (INIS)

Burden, M.St.J.; Cross, K.B.

1979-01-01

An investigation into the use of rf sputtering for ion cleaning of insulating substrates before ion plating is reported. Initial experiments consisted of sputtering metals with rf power followed by the deposition of copper onto glass slides using rf plasma excitation and biasing supply. It was found that good quality films were obtained by rf ion plating onto plastics with excellent adhesion over a wide operating pressure range. A block schematic of the rf plasma excitation system is shown. (UK)

Serial co-sputtering. Development of a versatile coating technology and its characterization using the example of rate enhancement of metal oxides by co-doping; Serielles Co-Sputtern. Entwicklung einer flexiblen Beschichtungstechnologie und deren Charakterisierung am Beispiel der Ratenerhoehung von Metalloxiden durch Co-Dotierung

Energy Technology Data Exchange (ETDEWEB)

Austgen, Michael

2011-09-19

Focus of this work is the design and characterization of a versatile coating system based on magnetron sputter deposition. This technology consists of a rotary target (primary target) that will be sputtered at one position and also can be coated at a different position with a secondary material by another sputter process. This simultaneous operation and the serial order of two sputter processes is the serial co-sputter process. A highly elaborated gas separation allows the operation of the primary sputter process in a reactive gas atmosphere whereas the secondary process can be driven in a non-reactive atmosphere. Compared to conventional co-sputtering the gas separation enables a stable operation of the secondary sputter process even if reactive gas is added to the primary sputter process. To develop an understanding of the process dynamics of serial co-sputtering the rate enhancement of metal oxides by co-doping with heavy atoms has been investigated first. If heavy elements are added to the target material the collision cascades can be reflected back towards the target surface by a more efficient momentum transfer and therefore increase the sputtering rate. The addition of heavy atoms can be achieved by serial co-sputtering. In the secondary sputter process the heavy element will be sputter deposited onto the rotary target. When entering the erosion zone of the primary sputter process the heavy atoms will be partially sputtered away and partially recoil implanted beneath the target surface. The later will contribute to the sputter yield amplification effect described above. In this work the sputter yield amplification effect has been investigated for the metal oxides Al{sub 2}O{sub 3} and TiO{sub 2} by co-doping of a aluminum and titanium rotary target with the heavy element tungsten (Z=74) and bismuth (Z=83). The primary process variables are the O{sub 2}-gas flow which determines the working point of the primary sputtering process, the rotation speed of the

Influence of Substrate Biasing on (Ba,Sr)TiO3 Films Prepared by Electron Cyclotron Resonance Plasma Sputtering

Science.gov (United States)

Matsumoto, Takeshi; Niino, Atsushi; Ohtsu, Yasunori; Misawa, Tatsuya; Yonesu, Akira; Fujita, Hiroharu; Miyake, Shoji

2004-03-01

(Ba,Sr)TiO3 (BST) films were deposited by electron cyclotron resonance (ECR) plasma sputtering with mirror confinement. DC bias voltage was applied to Pt/Ti/SiO2/Si substrates during deposition to vary the intensity of bombardment of energetic ions and to modify film properties. BST films deposited on the substrates at floating potential (approximately +20 V) were found to be amorphous, while films deposited on +40 V-biased substrates were crystalline in spite of a low substrate temperature below 648 K. In addition, atomic diffusion, which causes deterioration in the electrical properties of the films, was hardly observed in the crystallized films deposited with +40 V bias perhaps due to the low substrate temperature. Plasma diagnoses revealed that application of a positive bias to the substrate reduced the energy of ion bombardment and increased the density of excited neutral particles, which was assumed to result in the promotion of chemical reactions during deposition and the crystallization of BST films at a low temperature.

Deuterium trapping in tungsten deposition layers formed by deuterium plasma sputtering

International Nuclear Information System (INIS)

Alimov, V.Kh.; Roth, J.; Shu, W.M.; Komarov, D.A.; Isobe, K.; Yamanishi, T.

2010-01-01

A study of the influence of the deposition conditions on the surface morphology and deuterium (D) concentration in tungsten (W) deposition layers formed by magnetron sputtering and in the linear plasma generator has been carried out. Thick W layers (≥0.4 μm) deposited onto copper substrates demonstrate areas of pilling and, after post-deposition heating to 1300 K, flaking-off and fracturing. For thin W layers (≤80 nm) deposited onto stainless steel (SS) and W substrates, no areas of flaking-off and fracturing exist both after deposition and after post-deposition heating to 673 K for the SS substrate and to 1300 K for the W substrate. The concentration of deuterium in the W layers was found to decrease with increasing substrate temperature and with increasing tungsten deposition rate. For layers with relatively high concentration of oxygen (0.20-0.60 O/W), a decrease of the D concentration with increasing substrate temperature is more pronounced than that for layers deposited in good vacuum conditions. To describe the evolution of the D/W ratio with the substrate temperature and the tungsten deposition rate, an empirical equation proposed by De Temmerman and Doerner [J. Nucl. Mater. 389 (2009) 479] but with alternative parameters has been used.

Study of crude and plasma-treated heavy oil by low- and high-field 1H NMR

Energy Technology Data Exchange (ETDEWEB)

Honorato, Hercilio D. A.; Silva, Renzo C.; Junior, Valdemar Lacerda; Castro, Eustaquio V. R. de; Freitas, Jair C. C. [Research and Methodology Development Laboratory for Crude Oil Analysis - LabPetro, Department of Chemistry, Federal University of Espirito Santo (Brazil)], email: jairccfreitas@yahoo.com.br; Piumbini, Cleiton K.; Cunha, Alfredo G.; Emmerich, Francisco G. [Department of Physics, Federal University of Espirito Santo (Brazil); Souza, Andre A. de; Bonagamba, Tito J. [Institute of Physics of Sao Carlos, University of Sao Paulo (Brazil)

2010-07-01

This document is intended to describe the combination of H low-field NMR and thermogravimetry (TG), rheological measurement and H high-field NMR to assess the physical and chemical changes that can occur in a heavy crude oil from treatment in a plasma reactor. This research was done using a heavy crude oil, API gravity of 10.1, which was treated in a double dielectric barrier (DDB) plasma reactor using different plasma gases: natural gas (NG), C02 or H2. The low-field HNMR experiments were conducted in a Maran Ultra spectrometer, from Oxford Instruments, at 27.5? C. After rheological analysis, a reduction in the viscosity of the plasma-treated oils in comparison to that of the crude oil was observed. Finally, it was confirmed that the use of H low-field NMR relaxometry and H high-field NMR spectroscopy allowed a separate analysis of the effects of the plasma treatment on the water and oil fractions to be made.

Particle beam experiments for the analysis of reactive sputtering processes in metals and polymer surfaces

Energy Technology Data Exchange (ETDEWEB)

Corbella, Carles; Grosse-Kreul, Simon; Kreiter, Oliver; Arcos, Teresa de los; Benedikt, Jan; Keudell, Achim von [RD Plasmas with Complex Interactions, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum (Germany)

2013-10-15

A beam experiment is presented to study heterogeneous reactions relevant to plasma-surface interactions in reactive sputtering applications. Atom and ion sources are focused onto the sample to expose it to quantified beams of oxygen, nitrogen, hydrogen, noble gas ions, and metal vapor. The heterogeneous surface processes are monitored in situ by means of a quartz crystal microbalance and Fourier transform infrared spectroscopy. Two examples illustrate the capabilities of the particle beam setup: oxidation and nitriding of aluminum as a model of target poisoning during reactive magnetron sputtering, and plasma pre-treatment of polymers (PET, PP)

Study of the Matrix Effect on the Plasma Characterization of Heavy Elements in Soil Sediments

Directory of Open Access Journals (Sweden)

Tawfik W.

2007-01-01

Full Text Available Laser-induced breakdown spectroscopy (LIBS has been applied to perform a study of the matrix effect on the plasma characterization of soil sediment targets. The plasma is generated by focusing a pulsed Nd: YAG laser on the target in air at atmospheric pressure. The plasma emission spectrum was detected using a portable Echelle spectrometer (Mechelle 7500 — Multichannel Instruments, Stockholm, Sweden with intensified CCD camera. Spectroscopic analysis of plasma evolution of laser produced plasmas has been characterized in terms of their spectra, and electron temperature. Four heavy elements V, Pb, Mn and Co were determined in the obtained spectra. The LTE and optically thin plasma conditions were verified for the produced plasma. The electron temperature and density were determined using the emission intensity and stark broadening, respectively, of the spectral lines of the heavy elements in the soil sediments. The electron temperature does not change with concentration. For environmental applications, the obtained results showed the capability of the proposed LIBS setup with the portable Mechelle 7500 spectrometer to be applied in-situ for real-time measurements of the variation of the matrix elemental composition of soil sediments by following up only a single element as a marker for the composition of the soil sediment without need of analysis of the other elements.

Structural, optical and electrical peculiarities of r.f. plasma sputtered indium tin oxide films

International Nuclear Information System (INIS)

Boycheva, Sylvia; Sytchkova, Anna Krasilnikova; Grilli, Maria Luisa; Piegari, Angela

2007-01-01

In this work the influence of the deposition conditions on the structural, electrical and optical properties of the ITO films was studied. Films were deposited by r.f. plasma sputtering technique in Ar and varying Ar + O 2 gas mixtures, with and without substrate heating. Transmittance and reflectance of the films were measured in the range 350-2500 nm; the refractive index (n) and the extinction coefficient (k) were calculated by the spectral data simulation. The sheet resistance of the films was measured by four-point probe method. X-ray diffraction analysis was performed to study the texture of the films. Threshold behaviour was observed in the optical and electrical properties of ITO films deposited in Ar + O 2 atmosphere at a certain oxygen concentration determined by a fix combination of all other deposition conditions. A schematic diagram for the change of the film properties versus composition was suggested, which explains the obtained results

Methods of optimization of reactive sputtering conditions of Al target during AlN films deposition

Directory of Open Access Journals (Sweden)

Chodun Rafal

2015-12-01

Full Text Available Encouraged by recent studies and considering the well-documented problems occurring during AlN synthesis, we have chosen two diagnostic methods which would enable us to fully control the process of synthesis and characterize the synthesized aluminum nitride films. In our experiment we have compared the results coming from OES measurements of plasma and circulating power characteristics of the power supply with basic features of the deposited layers. The dual magnetron system operating in AC mode was used in our studies. Processes of aluminum target sputtering were carried out in an atmosphere of a mixture of argon and nitrogen. The plasma emission spectra were measured with the use of a monochromator device. Analyses were made by comparing the positions and intensities of spectral lines of the plasma components. The results obtained allowed us to characterize the sputtering process under various conditions of gas mixture compositions as well as power distribution more precisely, which is reported in this work. The measured spectra were related to the deposition rate, the structure morphology of the films and chemical composition. Our work proved that the use of plasma OES and circulating power measurements make possible to control the process of sputtering and synthesis of deposited films in situ.

Isotope puzzle in sputtering

International Nuclear Information System (INIS)

Zheng Liping

1998-01-01

Mechanisms affecting multicomponent material sputtering are complex. Isotope sputtering is the simplest in the multicomponent materials sputtering. Although only mass effect plays a dominant role in the isotope sputtering, there is still an isotope puzzle in sputtering by ion bombardment. The major arguments are as follows: (1) At the zero fluence, is the isotope enrichment ejection-angle-independent or ejection-angle-dependent? (2) Is the isotope angular effect the primary or the secondary sputter effect? (3) How to understand the action of momentum asymmetry in collision cascade on the isotope sputtering?

Polarization mechanism for Bremsstrahlung and radiative recombination in a plasma with heavy ions

International Nuclear Information System (INIS)

Astapenko, V.A.; Bureeva, L.A.; Lisitsa, V.S.

2002-01-01

Contribution of polarization channel into radiation and recombination of electrons in plasma with heavy ions is investigated. Cases of hot plasma with temperature T e = 0.5 keV and Fe, Mo, W, U ions and relatively cold plasma with temperature 0.1-10 eV are considered. Calculations of spectral characteristics, full cross sections and recombination rates in plasma are made, bearing in mind its real ionization equilibrium. The calculations are made on the basis of quasiclassical approximation for electron scattering and statistical model of ions. It is shown that contribution of polarization channel is essential both for effective radiation and full rate of radiative recombination [ru

RF Reactive Magnetron Sputter Deposition of Silicon Sub-Oxides

NARCIS (Netherlands)

Hattum, E.D. van

2007-01-01

RF reactive magnetron plasma sputter deposition of silicon sub oxide E.D. van Hattum Department of Physics and Astronomy, Faculty of Sciences, Utrecht University The work described in the thesis has been inspired and stimulated by the use of SiOx layers in the direct inductive printing technology,

Influence of substrate pre-treatments by Xe{sup +} ion bombardment and plasma nitriding on the behavior of TiN coatings deposited by plasma reactive sputtering on 100Cr6 steel

Energy Technology Data Exchange (ETDEWEB)

Vales, S., E-mail: sandra.vales@usp.br [Universidade de São Paulo (USP), Escola de Engenharia de São Carlos, Av. Trabalhador São Carlense 400, São Carlos, SP CEP 13566-590 (Brazil); Brito, P., E-mail: ppbrito@gmail.com [Pontifícia Universidade Católica de Minas Gerais (PUC-MG), Av. Dom José Gaspar 500, 30535-901 Belo Horizonte, MG (Brazil); Pineda, F.A.G., E-mail: pipe8219@gmail.com [Universidade de São Paulo (USP), Escola de Engenharia de São Carlos, Av. Trabalhador São Carlense 400, São Carlos, SP CEP 13566-590 (Brazil); Ochoa, E.A., E-mail: abigail_ochoa@hotmail.com [Universidade Estadual de Campinas (UNICAMP), Campus Universitário Zeferino Vaz, Barão Geraldo, Campinas, SP CEP 13083-970 (Brazil); Droppa, R., E-mail: roosevelt.droppa@ufabc.edu.br [Universidade Federal do ABC (UFABC), Av. dos Estados, 5001, Santo André, SP CEP 09210-580 (Brazil); Garcia, J., E-mail: jose.garcia@sandvik.com [Sandvik Coromant R& D, Lerkrogsvägen 19, SE-12680, Stockholm (Sweden); Morales, M., E-mail: monieriz@gmail.com [Universidade Estadual de Campinas (UNICAMP), Campus Universitário Zeferino Vaz, Barão Geraldo, Campinas, SP CEP 13083-970 (Brazil); Alvarez, F., E-mail: alvarez@ifi.unicamp.br [Universidade Estadual de Campinas (UNICAMP), Campus Universitário Zeferino Vaz, Barão Geraldo, Campinas, SP CEP 13083-970 (Brazil); and others

2016-07-01

In this paper the influence of pre-treating a 100Cr6 steel surface by Xe{sup +} ion bombardment and plasma nitriding at low temperature (380 °C) on the roughness, wear resistance and residual stresses of thin TiN coatings deposited by reactive IBAD was investigated. The Xe{sup +} ion bombardment was carried out using a 1.0 keV kinetic energy by a broad ion beam assistance deposition (IBAD, Kaufman cell). The results showed that in the studied experimental conditions the ion bombardment intensifies nitrogen diffusion by creating lattice imperfections, stress, and increasing roughness. In case of the combined pre-treatment with Xe{sup +} ion bombardment and subsequent plasma nitriding, the samples evolved relatively high average roughness and the wear volume increased in comparison to the substrates exposed to only nitriding or ion bombardment. - Highlights: • Effect of Xe ion bombardment and plasma nitriding on TiN coatings was investigated. • Xe ion bombardment with 1.0 KeV increases nitrogen retention in plasma nitriding. • 1.0 KeV ion impact energy causes sputtering, thus increasing surface roughness. • TiN coating wear is minimum after plasma nitriding due to lowest roughness.

An EDDY/particle-in-cell simulation of erosion of plasma facing walls bombarded by a collisional plasma

International Nuclear Information System (INIS)

Inai, Kensuke; Ohya, Kaoru

2011-01-01

To investigate the erosion of a plasma-facing wall intersecting an oblique magnetic field, we performed a kinetic particle-in-cell (PIC) simulation of magnetized plasma, in which collision processes between charged and neutral particles were taken into account. Sheath formation and local physical quantities, such as the incident angle and energy distributions of plasma ions at the wall, were examined at a plasma density of 10 18 m -3 , a temperature of 10 eV, and a magnetic field strength of 5 T. The erosion rate of a carbon wall was calculated using the ion-solid interaction code EDDY. At a high neutral density (>10 20 m -3 ), the impact energy of the ions dropped below the threshold for physical sputtering, so that the sputtering yield was drastically decreased and wall erosion was strongly suppressed. Sputter erosion was also suppressed when the angle of the magnetic field with respect to the surface normal was sufficiently large. (author)

The influence of target oxygen on the YBa2Cu3O6+δ DC Magnetron sputtering process

International Nuclear Information System (INIS)

Larsson, G.; Selinder, T.I.; Helmersson, U

1990-01-01

The oxygen partial pressure and the target potential have been monitored under a range of process conditions during single target dc magnetron sputtering of Y-Ba-Cu-O. The introduced sputtering gas consisted in all but one instance of pure argon and hence the oxygen present in the plasma originated mainly from the target. During the first hours of sputtering the oxygen partial pressure was of the same magnitude as the argon pressure (3.0 Pa). As the oxygen was released from the target and subsequently removed by pumping, the target potential increased and the film composition became more stoichiometric. After 30-40 hours of sputtering the target potential and the oxygen pressure stabilized and the film composition was equal to that of the stoichiometric target. If an oxygen flow exceeding a critical level was mixed into the sputtering gas the target potential and the deposition rate decreased swiftly. This was due to target oxidation, further manifested in changing plasma and target colours. In some instances the stabilization after 'presputtering' was incomplete and oscillations in target voltage and oxygen partial pressure were observed. The fluctuations made it virtually impossible to obtain stoichiometric films. The oscillative behaviour of the sputtering process is tentatively explained by a target temperature dependent oxygen diffusion. (au)

Solar system sputtering

Science.gov (United States)

Tombrello, T. A.

1982-01-01

The sites and materials involved in solar system sputtering of planetary surfaces are reviewed, together with existing models for the processes of sputtering. Attention is given to the interaction of the solar wind with planetary atmospheres in terms of the role played by the solar wind in affecting the He-4 budget in the Venus atmosphere, and the erosion and differentiation of the Mars atmosphere by solar wind sputtering. The study is extended to the production of isotopic fractionation and anomalies in interplanetary grains by irradiation, and to erosion effects on planetary satellites with frozen volatile surfaces, such as with Io, Europa, and Ganymede. Further measurements are recommended of the molecular form of the ejected material, the yields and energy spectra of the sputtered products, the iosotopic fractionation sputtering causes, and the possibility of electronic sputtering enhancement with materials such as silicates.

Plasma channel and Z-pinch dynamics for heavy ion transport

Energy Technology Data Exchange (ETDEWEB)

Ponce-Marquez, David [Univ. of California, Berkeley, CA (United States)

2002-01-01

A self stabilized, free standing, z-pinch plasma channel has been proposed to deliver the high intensity heavy ion beam from the end of a driver to the fuel target in a heavy ion inertial fusion power plant. The z-pinch relaxes emittance and energy spread requirements requiring a lower cost driver. A z-pinch transport would reduce the number of beam entry port holes to the target chamber from over a hundred to four as compared to neutralized ballistic focusing thus reducing the driver hardware exposure to neutron flux. Experiments where a double pulse discharge technique is used, z-pinch plasma channels with enhanced stability are achieved. Typical parameters are 7 kV pre-pulse discharge and 30 kV main bank discharge with 50 kA of channel current in a 7 torr background gas atmosphere. This work is an experimental study of these plasma channels examining the relevant physics necessary to understand and model such plasmas. Laser diagnostics measured the dynamical properties of neutrals and plasma. Schlieren and phase contrast techniques probe the pre-pulse gas dynamics and infrared interferometry and faraday effect polarimetry are used on the z-pinch to study its electron density and current distribution. Stability and repeatability of the z-pinch depend on the initial conditions set by the pre-pulse. Results show that the z-pinch channel is wall stabilized by an on-axis gas density depression created by the pre-pulse through hydrodynamic expansion where the ratio of the initial gas density to the final gas density is > 10/1. The low on-axis density favors avalanching along the desired path for the main bank discharge. Pinch time is around 2 s from the main bank discharge initiation with a FWHM of ~ 2 cm. Results also show that typical main bank discharge plasma densities reach 10¹⁷ cm^-3 peak on axis for a 30 kV, 7 torr gas nitrogen discharge. Current rise time is limited by the circuit-channel inductance with the highest contribution to the

Far-and mid-infrared properties of carbon layers elaborated by plasma sputtering

Energy Technology Data Exchange (ETDEWEB)

Rousseau, Benoit, E-mail: benoit.rousseau@univ-nantes.fr [Université de Nantes, CNRS, LTN UMR6607, La Chantrerie, Rue Christian Pauc, B.P. 50609, F-44306 Nantes Cedex 3 (France); Ammar, Mohamed Ramzi; Bormann, Denis; Simon, Patrick [CNRS, CEMHTI UPR3079, Université d' Orléans, F-55071 (France); Rabat, Hervé; Brault, Pascal [Université d' Orléans, CNRS, GREMI UMR7344, BP 6744, F-45067 Orléans Cedex 2 (France)

2016-12-30

Highlights: • Magnetron sputtering deposition of columnar, disordered carbon films. • Sputtered carbon films infrared properties are dependent on the local order. • Film texture at the micro-nanoscale explains difference of optical properties. - Abstract: The far-and mid-infrared reflectivity spectra of two carbon layers deposited on pure (100) silicon substrates by DC magnetron sputtering were investigated at room temperature in the 10–5000 cm{sup −1} wavenumber range. Their structural and textural features were also studied by combining Raman spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HRTEM), X-Ray Reflectivity (XRR) and Rutherford Backscattering Spectroscopy (RBS). The set of results was used to discuss afterwards the influence of the texture on the infrared properties at varying length scale. Thereby, the two layers were found to be heterogeneous as assessed by RBS, XRR and FESEM and their thicknesses had been measured by XRR and FESEM. The information on the structural organization and “crystallite” size was given by Raman spectroscopy. The influence of both the textural and structural parameters on the measured infrared reflectivity spectra was discussed. Finally, a methodology was proposed to recover the intrinsic index of refraction and the intrinsic index of absorption of each layer.

ITO/InP solar cells: A comparison of devices fabricated by ion beam and RF sputtering of the ITO

Science.gov (United States)

Coutts, T. J.

1987-01-01

This work was performed with the view of elucidating the behavior of indium tin oxide/indium phosphide (ITO/InP) solar cells prepared by RF and ion beam sputtering. It was found that using RF sputter deposition of the ITO always leads to more efficient devices than ion beam sputter deposition. An important aspect of the former technique is the exposure of the single crystal p-InP substrates to a very low plasma power prior to deposition. Substrates treated in this manner have also been used for ion beam deposition of ITO. In this case the cells behave very similarly to the RF deposited cells, thus suggesting that the lower power plasma exposure (LPPE) is the crucial process step.

Flexible Al-doped ZnO films grown on PET substrates using linear facing target sputtering for flexible OLEDs

International Nuclear Information System (INIS)

Jeong, Jin-A; Shin, Hyun-Su; Choi, Kwang-Hyuk; Kim, Han-Ki

2010-01-01

We report the characteristics of flexible Al-doped zinc oxide (AZO) films prepared by a plasma damage-free linear facing target sputtering (LFTS) system on PET substrates for use as a flexible transparent conducting electrode in flexible organic light-emitting diodes (OLEDs). The electrical, optical and structural properties of LFTS-grown flexible AZO electrodes were investigated as a function of dc power. We obtained a flexible AZO film with a sheet resistance of 39 Ω/□ and an average transmittance of 84.86% in the visible range although it was sputtered at room temperature without activation of the Al dopant. Due to the effective confinement of the high-density plasma between the facing AZO targets, the AZO film was deposited on the PET substrate without plasma damage and substrate heating caused by bombardment of energy particles. Moreover, the flexible OLED fabricated on the AZO/PET substrate showed performance similar to the OLED fabricated on a ITO/PET substrate in spite of a lower work function. This indicates that LFTS is a promising plasma damage-free and low-temperature sputtering technique for deposition of flexible and indium-free AZO electrodes for use in cost-efficient flexible OLEDs.

A Plasma Lens for Magnetron Sputtering

International Nuclear Information System (INIS)

Anders, Andre; Brown, Jeff

2010-01-01

A plasma lens, consisting of a solenoid and potential-defining ring electrodes, has been placed between a magnetron and substrates to be coated. Photography reveals qualitative information on excitation, ionization, and the transport of plasma to the substrate.

Heavy Neutral Beam Probe for Edge Plasma Analysis in Tokamaks

Energy Technology Data Exchange (ETDEWEB)

Castracane, J.

2001-01-04

The Heavy Neutral Beam Probe (HNBP) developed initially with DOE funding under the Small Business Innovation Research (SBIR) program was installed on the Tokamak de Varennes (TdeV) at the CCFM. This diagnostic was designed to perform fundamental measurements of edge plasma properties. The hardware was capable of measuring electron density and potential profiles with high spatial and temporal resolution. Fluctuation spectra for these parameters were obtained with HNBP for transport studies.

Heavy Neutral Beam Probe for Edge Plasma Analysis in Tokamaks

International Nuclear Information System (INIS)

Castracane, J.

2001-01-01

The Heavy Neutral Beam Probe (HNBP) developed initially with DOE funding under the Small Business Innovation Research (SBIR) program was installed on the Tokamak de Varennes (TdeV) at the CCFM. This diagnostic was designed to perform fundamental measurements of edge plasma properties. The hardware was capable of measuring electron density and potential profiles with high spatial and temporal resolution. Fluctuation spectra for these parameters were obtained with HNBP for transport studies

Contribution of energetic and heavy ions to the plasma pressure: The 27 September to 3 October 2002 storm

Science.gov (United States)

Kronberg, E. A.; Welling, D.; Kistler, L. M.; Mouikis, C.; Daly, P. W.; Grigorenko, E. E.; Klecker, B.; Dandouras, I.

2017-09-01

Magnetospheric plasma sheet ions drift toward the Earth and populate the ring current. The ring current plasma pressure distorts the terrestrial internal magnetic field at the surface, and this disturbance strongly affects the strength of a magnetic storm. The contribution of energetic ions (>40 keV) and of heavy ions to the total plasma pressure in the near-Earth plasma sheet is not always considered. In this study, we evaluate the contribution of low-energy and energetic ions of different species to the total plasma pressure for the storm observed by the Cluster mission from 27 September until 3 October 2002. We show that the contribution of energetic ions (>40 keV) and of heavy ions to the total plasma pressure is ≃76-98.6% in the ring current and ≃14-59% in the magnetotail. The main source of oxygen ions, responsible for ≃56% of the plasma pressure of the ring current, is located at distances earthward of XGSE ≃ -13.5 RE during the main phase of the storm. The contribution of the ring current particles agrees with the observed Dst index. We model the magnetic storm using the Space Weather Modeling Framework (SWMF). We assess the plasma pressure output in the ring current for two different ion outflow models in the SWMF through comparison with observations. Both models yield reasonable results. The model which produces the most heavy ions agrees best with the observations. However, the data suggest that there is still potential for refinement in the simulations.

Nanostructured hydroxyapatite/TiO2 composite coating applied to commercially pure titanium by a co-sputtering technique

International Nuclear Information System (INIS)

Lee, Baek-Hee; Koshizaki, Naoto

2008-01-01

We demonstrate an approach for the coating of nanostructured hydroxyapatite(HAP)/TiO 2 composite on commercially pure Ti (CP-Ti) by a co-sputtering process. HAP/TiO 2 composite film was obtained by controlling the processing pressure. It was observed that decomposition of HAP into CaO was easily induced during sputtering at 0.53 Pa, a typical sputtering condition for film deposition. However, HAP/TiO 2 composite film was obtained with the sputtering pressure of 2.67 Pa. The Ca/P ratio was nearly maintained at 1.66 by sputter deposition at 2.67 Pa. We further confirmed by analysis of plasma spectral emission that the variation of the hydroxyl (OH) radical present was due to the Ar pressure during sputtering. It has been shown that HAP coatings are dependent on the processing pressure, which the hydroxyl radical requires in order to create HAP

Sputtering/redeposition analysis of alkali-based tungsten composites for limiter/divertor applications

International Nuclear Information System (INIS)

DeWald, A.B.; Krauss, A.R.; Gruen, D.M.; Valentine, M.G.

1986-07-01

Composites of porous tungsten infiltrated with alkali metal-bearing alloys have been projected as a means of reducing plasma impurities and sputter erosion in magnetic fusion devices. Self-sustaining alkali metal overlayers have been observed to inhibit erosion of the underlying structural substrate by 2X to 10X. The alkali metal itself, insofar as it sputters as a secondary ion, is trapped at the surface by sheath potential and tangential magnetic fields. Self-regeneration of the alkali metal coating is obtained by thermal and radiation-induced segregation from the bulk

Spatially resolved electron density and electron energy distribution function in Ar magnetron plasmas used for sputter-deposition of ZnO-based thin films

Energy Technology Data Exchange (ETDEWEB)

Maaloul, L.; Gangwar, R. K.; Morel, S.; Stafford, L., E-mail: luc.stafford@umontreal.ca [Département de Physique, Université de Montréal, Montréal, Québec H3C 3J7 (Canada)

2015-11-15

Langmuir probe and trace rare gases optical emission spectroscopy were used to analyze the spatial structure of the electron density and electron energy distribution function (EEDF) in a cylindrical Ar magnetron plasma reactor used for sputter-deposition of ZnO-based thin films. While a typical Bessel (zero order) diffusion profile was observed along the radial direction for the number density of charged particles at 21 cm from the ZnO target, a significant rise of these populations with respect to the Bessel function was seen in the center of the reactor at 4 cm from the magnetron surface. As for the EEDF, it was found to transform from a more or less Maxwellian far from the target to a two-temperature Maxwellian with a depletion of high-energy electrons where magnetic field confinement effects become important. No significant change in the behavior of the electron density and EEDF across a wide range of pressures (5–100 mTorr) and self-bias voltages (115–300 V) was observed during magnetron sputtering of Zn, ZnO, and In{sub 2}O{sub 3} targets. This indicates that sputtering of Zn, In, and O atoms do not play a very significant role on the electron particle balance and electron heating dynamics, at least over the range of experimental conditions investigated.

RF Plasma Source for Heavy Ion Beam Charge Neutralization

Science.gov (United States)

Efthimion, P. C.; Gilson, E.; Grisham, L.; Davidson, R. C.

2003-10-01

Highly ionized plasmas are being employed as a medium for charge neutralizing heavy ion beams in order to focus to a small spot size. Calculations suggest that plasma at a density of 1 - 100 times the ion beam density and at a length 0.1-0.5 m would be suitable for achieving a high level of charge neutralization. An ECR source has been built at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization with plasma. The ECR source operates at 13.6 MHz and with solenoid magnetic fields of 0-10 gauss. The goal is to operate the source at pressures 10-5 Torr at full ionization. The initial operation of the source has been at pressures of 10-4 - 10-1 Torr. Electron densities in the range of 10^8 - 10^11 cm-3 have been achieved. Recently, pulsed operation of the source has enabled operation at pressures in the 10-6 Torr range with densities of 10^11 cm-3. Near 100% ionization has been achieved. The source has been integrated with NTX and is being used in the experiments. The plasma is approximately 10 cm in length in the direction of the beam propagation. Modifications to the source will be presented that increase its length in the direction of beam propagation.

Ion-surface interaction: simulation of plasma-wall interaction (ITER)

International Nuclear Information System (INIS)

Salou, Pierre

2013-01-01

The wall materials of magnetic confinement in fusion machines are exposed to an aggressive environment; the reactor blanket is bombarded with a high flux of particles extracted from the plasma, leading to the sputtering of surface material. This sputtering causes wall erosion as well as plasma contamination problems. In order to control fusion reactions in complex reactors, it is thus imperative to well understand the plasma-wall interactions. This work proposes the study of the sputtering of fusion relevant materials. We propose to simulate the charged particles influx by few keV single-charged ion beams. This study is based on the catcher method; to avoid any problem of pollution (especially in the case of carbon) we designed a new setup allowing an in situ Auger electron spectroscopy analysis. The results provide the evolution of the angular distribution of the sputtering yield as a function of the ion mass (from helium to xenon) and its energy (from 3 keV to 9 keV). (author) [fr

Temperature dependence of InN film deposition by an RF plasma-assisted reactive ion beam sputtering deposition technique

International Nuclear Information System (INIS)

Shinoda, Hiroyuki; Mutsukura, Nobuki

2005-01-01

Indium nitride (InN) films were deposited on Si(100) substrates using a radiofrequency (RF) plasma-assisted reactive ion beam sputtering deposition technique at various substrate temperatures. The X-ray diffraction patterns of the InN films suggest that the InN films deposited at substrate temperatures up to 370 deg C were cubic crystalline InN; and at 500 deg C, the InN film was hexagonal crystalline InN. In a scanning electron microscope image of the InN film surface, facets of cubic single-crystalline InN grains were clearly observed on the InN film deposited at 370 deg C. The inclusion of metallic indium appeared on the InN film deposited at 500 deg C

Surface erosion of fusion reactor components due to radiation blistering and neutron sputtering

International Nuclear Information System (INIS)

Das, S.K.; Kaminsky, M.

1975-01-01

Radiation blistering and neutron sputtering can lead to the surface erosion of fusion reactor components exposed to plasma radiations. Recent studies of methods to reduce the surface erosion caused by these processes are discussed

Influence of plasma pressure on the growth characteristics and ferroelectric properties of sputter-deposited PZT thin films

International Nuclear Information System (INIS)

Bose, A.; Maity, T.; Bysakh, S.; Seal, A.; Sen, Suchitra

2010-01-01

PZT thin films of thickness (320-1040) nm were synthesized on Si/SiO 2 /Ti/Pt multilayered substrates by radio frequency magnetron sputtering. The influence of plasma pressure in the range of (0.24-4.9) Pa, during deposition, on the structural, electrical and ferroelectric properties of the PZT films was systematically studied. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and cross-sectional transmission electron microscopy (XTEM) were employed for structural study. Nano-probe Energy Dispersive (EDX) line scanning was employed to investigate the elemental distribution across the film-bottom electrode interface. I-V characteristics and polarization-electric field (P-E) hysteresis loop of the films were measured. The study reveals that the plasma pressure has a strong influence on the evolution and texture of the ferroelectric perovskite phase and microstructure of the films. At an optimum plasma pressure of 4.1 Pa, PZT films are grown with 93% perovskite phase with (1 1 1) preferred orientation and uniform granular microstructure. These films show a saturation polarization of 67 μC/cm 2 , remnant polarization of 30 μC/cm 2 and coercive field of 28 kV/cm which, according to the literature, seem to be suitable for device applications. Transmission electron microscopy (TEM) study shows that at a plasma pressure of 4.1 Pa, the PZT/bottom Pt interface is sharp and no amorphous interlayer is formed at the interface. At a higher plasma pressure of 4.9 Pa, poor I-V and P-E hysteresis loop are observed which are interpreted as due to an amorphous interlayer at the film-bottom electrode interface which is possibly enriched in Pb, Zr, O and Pt.

Characterization and modelling of microwave multi dipole plasmas. Application to multi dipolar plasma assisted sputtering; Caracterization et modelisation des plasmas micro-onde multi-dipolaires. Application a la pulverisation assistee par plasma multi-dipolaire

Energy Technology Data Exchange (ETDEWEB)

Tran, Tan Vinh [Universite Joseph Fourier/CNRS-IN2P3, 53 Avenue des Martyrs, F-38026 Grenoble (France)

2006-07-01

the magnet has also shown a better radial confinement with magnets exhibiting high length over diameter ratios. In addition, the numerical study corroborates the results of the experimental study, i.e. an ECR coupling region close to the equatorial plane of the magnet and not near the end of the coaxial microwave line. Finally, these results have been successfully applied to plasma assisted sputtering of targets allowing, in particular, their uniform erosion. (author)

Determination of the oxidation mechanism to Cd Te obtained by rf reactive magnetron sputtering in a plasma of Ar-N{sub 2}O; Determinacion del mecanismo de oxigenacion del CdTe obtenido por rf sputtering reactivo con magnetron en un plasma de Ar-N{sub 2}O

Energy Technology Data Exchange (ETDEWEB)

Caballero B, F.; Zapata N, A.; Bartolo P, P.; Castro R, R.; Zapata T, M.; Cauich, W.; Pena, J.L. [Departamento de Fisica Aplicada, Centro deInvestigacion y de Estudios Avanzados, Instituto Politecnico Nacional, Unidad Merida, Apartado postal 73, Cordemex, 97310 Merida, Yucatan (Mexico)

1998-12-31

In this work we did studies to determinate the oxidation site and incorporation mechanism of oxygen to Cd Te, when preparing Cd Te:O thin films by r f reactive magnetron sputtering, using a Cd Te target and a controlled plasma of Ar-N{sub 2}O. We study the influence in the oxygen content in films due to the variation of N{sub 2}O partial pressure, plasma power and substrate position. We monitored the process in situ by mass spectrometry to determinate the variation of present compounds when varying the N{sub 2}O partial pressure and plasma power. Thin films composition was determined by Auger electron spectroscopy and their structure by X-ray diffraction. We demonstrate that oxygen incorporation has place mainly in the substrate, forming an amorphous Cd Te:O film. We found that exists Cd Te oxidation without using nitrous oxide, may be due to residual atmosphere. We demonstrate that Cd Te oxidation depends on nitrous oxide partial pressure and plasma power. We found that deposition rate of Cd Te:O thin films depend on nitrous oxide interaction with Cd Te in the target and on the chamber walls. We propose a reaction mechanism to explain the oxygen incorporation to Cd Te. (Author)

Reactive sputtering of TiN films at large substrate to target distances

International Nuclear Information System (INIS)

Musil, J.; Kadlec, S.

1990-01-01

This paper is a critical review of the present status of the magnetron ion sputter plating of thin CiN films. Thus different possibilities of extracting high ion currents 1 s from the magnetron discharge to substrates located not only at standard target to substrate distances d S-T of about 50 mm but also at larger distances d S-T are discussed in detail. Special attention is devoted to magnetron sputtering systems with enhanced ionization, to plasma confinement in the magnetron sputtering systems and to the discharge characteristics of an unbalanced magnetron (UM). It is shown that a UM can be operated in the regime of a double-site-sustained discharge (DSSD) and in this case large 1 s can be extracted to substrates located in large D S-T of about 200 mm and even at high pressures p = 5 Pa. A physical comparison of the conventional magnetron (CM), UM and DSSD is also given. Considerable attention is also devoted to the effect of ion bombardment on properties of TiN films created in the sputtering system using DSSD. (author)

Physics of plasma-wall interactions in controlled fusion

International Nuclear Information System (INIS)

Post, D.E.; Behrisch, R.

1984-01-01

In the areas of plasma physics, atomic physics, surface physics, bulk material properties and fusion experiments and theory, the following topics are presented: the plasma sheath; plasma flow in the sheath and presheath of a scrape-off layer; probes for plasma edge diagnostics in magnetic confinement fusion devices; atomic and molecular collisions in the plasma boundary; physical sputtering of solids at ion bombardment; chemical sputtering and radiation enhanced sublimation of carbon; ion backscattering from solid surfaces; implantation, retention and release of hydrogen isotopes; surface erosion by electrical arcs; electron emission from solid surfaces;l properties of materials; plasma transport near material boundaries; plasma models for impurity control experiments; neutral particle transport; particle confinement and control in existing tokamaks; limiters and divertor plates; advanced limiters; divertor tokamak experiments; plasma wall interactions in heated plasmas; plasma-wall interactions in tandem mirror machines; and impurity control systems for reactor experiments

Towards the dynamical study of heavy-flavor quarks in the Quark-Gluon-Plasma

International Nuclear Information System (INIS)

Berrehrah, H; Bratkovskaya, E; Cassing, W; Gossiaux, P B; Aichelin, J

2014-01-01

Within the aim of a dynamical study of on- and off-shell heavy quarks Q in the quark gluon plasma (QGP) – as produced in relativistic nucleus-nucleus collisions – we study the heavy quark collisional scattering on partons of the QGP. The elastic cross sections σ q,g−Q are evaluated for perturbative partons (massless on-shell particles) and for dynamical quasi-particles (massive off-shell particles as described by the dynamical quasi-particles model D QPM ) using the leading order Born diagrams. We demonstrate that the finite width of the quasi-particles in the DQPM has little influence on the cross sections σ q,g−Q except close to thresholds. We, furthermore, calculate the heavy quark relaxation time as a function of temperature T within the different approaches using these cross sections

Nonthermal plasma reactors for the production of light hydrocarbon olefins from heavy oil

Directory of Open Access Journals (Sweden)

G. Prieto

2003-03-01

Full Text Available During the last decade, nonthermal plasma technology was applied in many different fields, focusing attention on the destruction of harmful compounds in the air. This paper deals with nonthermal plasma reactors for the conversion of heavy oil into light hydrocarbon olefins, to be employed as gasoline components or to be added in small amounts for the catalytic reduction of nitrogen oxide compounds in the treatment of exhaust gas at power plants. For the process, the plate-plate nonthermal plasma reactor driven by AC high voltage was selected. The reactor was modeled as a function of parameter characteristics, using the methodology provided by the statistical experimental design. The parameters studied were gap distance between electrodes, carrier gas flow and applied power. Results indicate that the reactions occurring in the process of heavy oil conversion have an important selective behavior. The products obtained were C1-C4 hydrocarbons with ethylene as the main compound. Operating the parameters of the reactor within the established operative window of the system and close to the optimum conditions, efficiencies as high as 70 (mul/joule were obtained. These values validate the process as an in-situ method to produce light olefins for the treatment of nitrogen oxides in the exhaust gas from diesel engines.

Reduction of residual gas in a sputtering system by auxiliary sputter of rare-earth metal

International Nuclear Information System (INIS)

Li Dejie

2002-01-01

In film deposition by sputtering, the oxidation and nitrification of the sputtered material lead to degradation of film quality, particularly with respect to metal sulfide films. We propose to use auxiliary sputtering as a method to produce a fresh film of rare-earth metal, usually dysprosium (Dy), that absorbs the active gases in a sputtering system, greatly reducing the background pressure and protecting the film from oxidation and nitrification effectively. The influence of the auxiliary sputtering power consumption, sputtering time, and medium gas pressure on the background pressure in the vacuum chamber is investigated in detail. If the auxiliary sputtering power exceeds 120 W and the sputtering time is more than 4 min, the background pressure is only one fourth of the ultimate pressure pumped by an oil diffusion pump. The absorption activity of the sputtered Dy film continues at least an hour after completion of the auxiliary sputter. Applied to film deposition of Ti and ZnS, this technique has been proven to be effective. For the Ti film, the total content of N and O is reduced from 45% to 20% when the auxiliary sputtering power of Dy is 120 W, and the sputtering time is 20 min. In the case of ZnS, the content of O is reduced from 8% to 2%

Electrical properties of sputtered-indium tin oxide film contacts on n-type GaN

International Nuclear Information System (INIS)

Hwang, J. D.; Lin, C. C.; Chen, W. L.

2006-01-01

A transparent indium tin oxide (ITO) Ohmic contact on n-type gallium nitride (GaN) (dopant concentration of 2x10 17 cm -3 ) having a specific contact resistance of 4.2x10 -6 Ω cm 2 was obtained. In this study, ITO film deposition method was implemented by sputtering. We found that the barrier height, 0.68 eV, between ITO and n-type GaN is the same for both evaporated- and sputtered-ITO films. However, the 0.68 eV in barrier height renders the evaporated-ITO/n-GaN Schottky contact. This behavior is different from that of our sputtered-ITO/n-GaN, i.e., Ohmic contact. During sputtering, oxygen atoms on the GaN surface were significantly removed, thereby resulting in an improvement in contact resistance. Moreover, a large number of nitrogen (N) vacancies, caused by sputtering, were produced near the GaN surface. These N vacancies acted as donors for electrons, thus affecting a heavily doped n-type formed at the subsurface below the sputtered ITO/n-GaN. Both oxygen removal and heavy doping near the GaN surface, caused by N vacancies, in turn led to a reduction in contact resistivity as a result of electrons tunneling across the depletion layer from the ITO to the n-type GaN. All explanations are given by Auger analysis and x-ray photoelectron spectroscopy

THE MARINE HEAVY FUEL IGNITION AND COMBUSTION BY PLASMA

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MOROIANU CORNELIU

2015-05-01

Full Text Available The continuous damage of the used fuel quality, of its dispersion due to the increasing viscosity, make necessary the volume expansion and the rise of the e electric spark power used at ignition. A similar situation appears to the transition of the generator operation from the marine Diesel heavy fuel to the residues of water-fuel mixture. So, it feels like using an ignition system with high specific energy and power able to perform the starting and burning of the fuels mentioned above. Such a system is that which uses a low temperature plasma jet. Its use involves obtaining a high temperature area round about the jet, with a high discharge power, extending the possibility of obtaining a constant burning of different concentration (density mixtures. Besides the action of the temperature of the air-fuel mixture, the plasma jet raises the rate of oxidation reaction as a result of appearance of lot number of active centers such as loaded molecules, atoms, ions, free radicals.

Hysteresis behaviour of silver sputtered in different plasma atmospheres at constant flow rates

International Nuclear Information System (INIS)

Rizk, A.; Makar, L.N.; Rizk, N.S.; Shinoda, R.

1990-01-01

The effects of ion bombardment on sputtering behaviour of pure silver targets in inert and active gas atmospheres were investigated, using a dc planar magnetron sputtering system. The obtained current-voltage characteristics showed the formation of hysteresis loops without noticeable sharp transitions. Redeposited layers of silver nitride or silver oxide on the target surface when using nitrogen or oxygen in the glow discharge, residual ionization when using dry argon atmosphere were considered the main reasons for the occurrence of these loops. The results indicate that films of AgN x and AgO x can be deposited with controlled x in the range 0 ≤ x ≤ 1 using voltage control at constant gas flow rates. (author)

Plasma and BIAS Modeling: Self-Consistent Electrostatic Particle-in-Cell with Low-Density Argon Plasma for TiC

Directory of Open Access Journals (Sweden)

Jürgen Geiser

2011-01-01

processes. In this paper we present a new model taken into account a self-consistent electrostatic-particle in cell model with low density Argon plasma. The collision model are based of Monte Carlo simulations is discussed for DC sputtering in lower pressure regimes. In order to simulate transport phenomena within sputtering processes realistically, a spatial and temporal knowledge of the plasma density and electrostatic field configuration is needed. Due to relatively low plasma densities, continuum fluid equations are not applicable. We propose instead a Particle-in-cell (PIC method, which allows the study of plasma behavior by computing the trajectories of finite-size particles under the action of an external and self-consistent electric field defined in a grid of points.

Oblique Propagation of Electrostatic Waves in a Magnetized Electron-Positron-Ion Plasma in the Presence of Heavy Particles

Science.gov (United States)

Sarker, M.; Hossen, M. R.; Shah, M. G.; Hosen, B.; Mamun, A. A.

2018-06-01

A theoretical investigation is carried out to understand the basic features of nonlinear propagation of heavy ion-acoustic (HIA) waves subjected to an external magnetic field in an electron-positron-ion plasma that consists of cold magnetized positively charged heavy ion fluids and superthermal distributed electrons and positrons. In the nonlinear regime, the Korteweg-de Vries (K-dV) and modified K-dV (mK-dV) equations describing the propagation of HIA waves are derived. The latter admits a solitary wave solution with both positive and negative potentials (for K-dV equation) and only positive potential (for mK-dV equation) in the weak amplitude limit. It is observed that the effects of external magnetic field (obliqueness), superthermal electrons and positrons, different plasma species concentration, heavy ion dynamics, and temperature ratio significantly modify the basic features of HIA solitary waves. The application of the results in a magnetized EPI plasma, which occurs in many astrophysical objects (e.g. pulsars, cluster explosions, and active galactic nuclei) is briefly discussed.

Cathode and ion-luminescence of Eu:ZnO thin films prepared by reactive magnetron sputtering and plasma decomposition of non-volatile precursors

Energy Technology Data Exchange (ETDEWEB)

Gil-Rostra, Jorge [Instituto de Ciencia de Materiales de Sevilla, CSIC, Univ. Sevilla, C/Américo Vespucio 49, E-41092 Sevilla (Spain); Ferrer, Francisco J. [Centro Nacional de Aceleradores, CSIC, Univ. Sevilla, Av. Thomas A. Edison 7, E-41092 Sevilla (Spain); Martín, Inocencio R. [Departamento de Física Fundamental y Experimental, Electrónica y Sistemas, U. La Laguna, C/Astrofísico Francisco Sánchez s/n, E-38206 La Laguna, Santa Cruz de Tenerife (Spain); González-Elipe, Agustín R.; Yubero, Francisco [Instituto de Ciencia de Materiales de Sevilla, CSIC, Univ. Sevilla, C/Américo Vespucio 49, E-41092 Sevilla (Spain)

2016-10-15

This paper reports the luminescent behavior of Eu:ZnO thin films prepared by an one-step procedure that combines reactive magnetron sputtering deposition of ZnO with the plasma activated decomposition of a non-volatile acetylacetonate precursor of Eu sublimated in an effusion cell. Chemical composition and microstructure of the Eu:ZnO thin films have been characterized by several methods and their photo-, cathode- and ion-luminescent properties studied as a function of Eu concentration. The high transparency and well controlled optical properties of the films have demonstrated to be ideal for the development of cathode- and ion- luminescence sensors.

Study of plasma confinement in ELMO Bumpy Torus with a heavy-ion beam probe

Energy Technology Data Exchange (ETDEWEB)

Bieniosek, F. M.

1981-01-01

Plasma confinement in ELMO Bumpy Torus (EBT) is generally strongly dependent on an ambipolar electric field. Spatially resolved measurements of the resulting electric space potential phi/sub sp/ have been made in a single plasma cross section by the heavy-ion beam probe. This diagnostic injects a 4-60-keV beam of (usually) Cs/sup +/ ions into the plasma. Measurement of the energy of Cs/sup 2 +/ secondary ions leaving the plasma gives a continuous monitor of the local space potential. In addition, the total detected Cs/sup 2 +/ ion current is proportional to the product of the local electron density and the ionization rate, which, in turn, is a function of the electron temperature. This signal, nf(T/sub e/), is sensitive to all three electron distributions found in EBT - those of the cold surface plasma, the warm core plasma, and the hot electron ring.

Study of plasma confinement in ELMO Bumpy Torus with a heavy-ion beam probe

International Nuclear Information System (INIS)

Bieniosek, F.M.

1981-01-01

Plasma confinement in ELMO Bumpy Torus (EBT) is generally strongly dependent on an ambipolar electric field. Spatially resolved measurements of the resulting electric space potential phi/sub sp/ have been made in a single plasma cross section by the heavy-ion beam probe. This diagnostic injects a 4-60-keV beam of (usually) Cs + ions into the plasma. Measurement of the energy of Cs 2+ secondary ions leaving the plasma gives a continuous monitor of the local space potential. In addition, the total detected Cs 2+ ion current is proportional to the product of the local electron density and the ionization rate, which, in turn, is a function of the electron temperature. This signal, nf(T/sub e/), is sensitive to all three electron distributions found in EBT - those of the cold surface plasma, the warm core plasma, and the hot electron ring

Reactive sputter deposition

CERN Document Server

Mahieu, Stijn

2008-01-01

In this valuable work, all aspects of the reactive magnetron sputtering process, from the discharge up to the resulting thin film growth, are described in detail, allowing the reader to understand the complete process. Hence, this book gives necessary information for those who want to start with reactive magnetron sputtering, understand and investigate the technique, control their sputtering process and tune their existing process, obtaining the desired thin films.

Tubulointerstitial nephritis accompanying gamma-heavy chain deposition and gamma-heavy chain restricted plasma cells in the kidney.

Science.gov (United States)

Nayer, Ali; Green, Dollie F; Gonzalez-Suarez, Maria L; Sujoy, Victoria; Ikpatt, Offiong F; Thomas, David B

2014-09-01

Monoclonal immunoglobulin heavy chain (HC) diseases are rare proliferative disorders of B lymphocytes or plasma cells characterized by the presence of monoclonal α-, µ-, or γ-HC without associated light chains in the blood, urine, or both. We report a 59-year-old woman with a history of Hodgkin disease who developed hypercalcemia, proteinuria, and impaired kidney function. Protein electrophoresis and immunofixation displayed γ-HC without associated light chains in the serum and urine. Pathologic examination demonstrated severe tubulointerstitial nephritis associated with diffuse and strong linear staining of the glomerular and tubular basement membranes as well as Bowman capsules for γ-HC, but not for κ- or λ-light chains. Immunohistochemical examination of the kidney and bone marrow demonstrated numerous CD138+ plasma cells immunoreactive for γ-HC, but not for κ- or λ-light chains. This is the first report of tubulointerstitial nephritis associated with γ-HC deposition and γ-HC restricted plasma cells in the kidney. This report heightens awareness about tubulointerstitial nephritis as a possible manifestation of γ-HC deposition in the kidney.

The errant life of a heavy quark in the quark-gluon plasma

International Nuclear Information System (INIS)

Meyer, Harvey B

2011-01-01

In the high-temperature phase of QCD, the heavy-quark momentum diffusion constant determines, via a fluctuation-dissipation relation, how fast a heavy quark kinetically equilibrates. This transport coefficient can be extracted from thermal correlators via a Kubo formula. We present a lattice calculation of the relevant Euclidean correlators in the gluon plasma, based on a recent formulation of the problem in heavy-quark effective field theory (HQET). We find a ∼20% enhancement of the Euclidean correlator at maximal time separation as the temperature is lowered from 6T c to 2T c , pointing to stronger interactions at lower temperatures. At the same time, the correlator becomes flatter from 6T c down to 2T c , indicating a relative shift of the spectral weight to lower frequencies. A recent next-to-leading order perturbative calculation of the correlator agrees with the time dependence of the lattice data at the few-per cent level. We estimate how much additional contribution from the ω∼ c .

Ferroelectric plasma source for heavy ion beam space charge neutralization

International Nuclear Information System (INIS)

Efthimion, Philip C.; Gilson, Erik P.; Davidson, Ronald C.; Grisham, Larry; Grant Logan, B.; Seidl, Peter A.; Waldron, William; Yu, Simon S.

2007-01-01

Plasmas are a source of unbound electrons for charge neutralizing intense heavy ion beams to allow them to focus to a small spot size and compress their axial pulse length. The plasma source should be able to operate at low neutral pressures and without strong externally applied electric or magnetic fields. To produce 1 m-long plasma columns, sources based upon ferroelectric ceramics with large dielectric coefficients are being developed. The sources utilize the ferroelectric ceramic BaTiO 3 to form metal plasma. The drift tube inner surface of the Neutralized Drift Compression Experiment (NDCX) will be covered with ceramic material, and high voltage (∼7 kV) will be applied between the drift tube and the front surface of the ceramics. A prototype ferroelectric source, 20 cm in length, has produced plasma densities of 5x10 11 cm -3 . It was integrated into the Neutralized Transport Experiment (NTX), and successfully charge neutralized the K + ion beam. A 1 m-long source comprised of five 20-cm-long sources has been tested. Simply connecting the five sources in parallel to a single pulse forming network power supply yielded non-uniform performance due to the time-dependent nature of the load that each of the five plasma sources experiences. Other circuit combinations have been considered, including powering each source by its own supply. The 1-m-long source has now been successfully characterized, producing relatively uniform plasma over the 1 m length of the source in the mid-10 10 cm -3 density range. This source will be integrated into the NDCX device for charge neutralization and beam compression experiments

A fundamental analysis of the validity of thermodynamic models of ionized and excited particle production during sputtering

International Nuclear Information System (INIS)

Snowdon, K.J.

1979-01-01

The concept of LTE and its existence criteria are applied to the sputtering problem. After presenting arguments against the existence of LTE within the solid, expressions are derived which allow a calculation of the minimum secondary electron yields and sputtering conditions required for the establishment of partial and complete LTE within the hemisphere or hemispherical shell immediately above the point of impact of an incident, heavy projectile. It is found by application of the theory of 50 keV Ar + bombardment of zinc that secondary electron yields per incident projectile of greater than 10 5 are required before either complete, or partial, LTE can be established during sputtering. Further refinements of the model are not expected to reduce this figure the four or more orders of magnitude required for agreement with experimental yields. (author)

Experimental setup for producing tungsten coated graphite tiles using plasma enhanced chemical vapor deposition technique for fusion plasma applications

International Nuclear Information System (INIS)

Chauhan, Sachin Singh; Sharma, Uttam; Choudhary, K.K.; Sanyasi, A.K.; Ghosh, J.; Sharma, Jayshree

2013-01-01

Plasma wall interaction (PWI) in fusion grade machines puts stringent demands on the choice of materials in terms of high heat load handling capabilities and low sputtering yields. Choice of suitable material still remains a challenge and open topic of research for the PWI community. Carbon fibre composites (CFC), Beryllium (Be), and Tungsten (W) are now being considered as first runners for the first wall components of future fusion machines. Tungsten is considered to be one of the suitable materials for the job because of its superior properties than carbon like low physical sputtering yield and high sputter energy threshold, high melting point, fairly high re-crystallization temperature, low fuel retention capabilities, low chemical sputtering with hydrogen and its isotopes and most importantly the reparability with various plasma techniques both ex-situ and in-situ. Plasma assisted chemical vapour deposition is considered among various techniques as the most preferable technique for fabricating tungsten coated graphite tiles to be used as tokamak first wall and target components. These coated tiles are more favourable compared to pure tungsten due to their light weight and easier machining. A system has been designed, fabricated and installed at SVITS, Indore for producing tungsten coated graphite tiles using Plasma Enhanced Chemical Vapor Deposition (PE-CVD) technique for Fusion plasma applications. The system contains a vacuum chamber, a turbo-molecular pump, two electrodes, vacuum gauges, mass analyzer, mass flow controllers and a RF power supply for producing the plasma using hydrogen gas. The graphite tiles will be put on one of the electrodes and WF6 gas will be inserted in a controlled manner in the hydrogen plasma to achieve the tungsten-coating with WF6 dissociation. The system is integrated at SVITS, Indore and a vacuum of the order of 3*10 -6 is achieved and glow discharge plasma has been created to test all the sub-systems. The system design with

Improvement of dielectric properties of BLT thin films deposited by magnetron sputtering

International Nuclear Information System (INIS)

Besland, M P; Barroy, P R J; Richard-Plouet, M; Tessier, P Y; Brohan, L; Djouadi, M A; Borderon, C; Tacon, S Le; Averty, D; Gundel, H W

2008-01-01

Well crystallized BLT thin films were deposited by RF magnetron sputtering using a target of Aurivillius phase Bi 3.25 La 0.75 Ti 3 O 12 (BLT 0,75 ), elaborated in our institute. RF sputtering experiments were performed at room temperature with an argon/oxygen mixture, in a pressure range of 20-50 mTorr. Optimisation of the plasma parameters, namely deposition pressure, RF power and oxygen content in the gas phase, allows obtaining BLT films with a chemical composition close to Bi 3.25 La 0.75 Ti 3 O 12 . After ex-situ annealing under oxygen atmosphere at 650 deg. C, BLT films deposited on Pt/TiO 2 /SiO 2 /Si (multilayer) substrates exhibit well defined rod-like grains morphology. A two step deposition process appeared to be necessary in order to reach satisfying dielectric properties. The effect of the plasma parameters on the chemical composition and electrical properties are presented and discussed

Fundamental aspects of cathodic sputtering

International Nuclear Information System (INIS)

Harman, R.

1979-01-01

The main fundamental aspects and problems of cathodic sputtering used mainly for thin film deposition and sputter etching are discussed. Among many types of known sputtering techniques the radiofrequency /RF/ diode sputtering is the most universal one and is used for deposition of metals, alloys, metallic compounds, semiconductors and insulators. It seems that nowadays the largest number of working sputtering systems is of diode type. Sometimes also the dc or rf triode sputtering systems are used. The problems in these processes are practically equivalent and comparable with the problems in the diode method and therefore our discussion will be, in most cases applicable for both, the diode and triode methods

A study of the plasma electronegativity in an argon-oxygen pulsed-dc sputter magnetron

International Nuclear Information System (INIS)

You, S D; Dodd, R; Edwards, A; Bradley, J W

2010-01-01

Using Langmuir probe-assisted laser photodetachment, the temporal evolution of the O - density was determined in the bulk plasma of a unipolar pulsed-dc magnetron. The source was operated in reactive mode, at a fixed nominal on-time power of 100 W, sputtering Ti in argon-oxygen atmospheres at 1.3 Pa pressure, but over a variation of duty cycles from 5% to 50% and oxygen partial pressures of 10% and 50% of the total pressure. In the plasma on-time, for all duty cycles the negative ion density (n - ) rises marginally reaching values typically less than 2 x 10 15 m -3 with negative ion-to-electron density ratios, α - falls by about 20-30% as fast O - species created at the cathode exit the system. This is followed by a rapid rise in n - to values at least 2 or 3 times that in the on-time. The rate of rise of n - and its maximum value both increase with decreasing duty cycle. In the off-time, the electron density falls rapidly (initial decay rates of several tens of μs), and therefore the afterglow plasma becomes highly electronegative, with α reaching 4.6 and 14.4 for 10% and 50% oxygen partial pressure, respectively. The rapid rise in n - in the afterglow (in which the electron temperature falls from about 5 to 0.5 eV) is attributed to the dissociative attachment of highly excited oxygen metastables, which themselves are created in the pulse on-time. At the lowest duty of 5%, the long-term O - decay times are several hundred μs. Langmuir probe characteristics show the clear signature that negative ions dominate over the electrons in the off-time. From the ion and electron saturation current ratios, α has been estimated in some chosen cases and found to agree within a factor between 2 and 10 with those obtained more directly from the photodetachment method.

Charge state analysis of heavy ions after penetration of uncleaned and sputter cleaned conducting surfaces

International Nuclear Information System (INIS)

Jung, M.; Schosnig, M.; Kroneberger, K.; Tobisch, M.; Maier, R.; Kuzel, M.; Fiedler, C.; Hofmann, D.; Groeneveld, K.O.

1994-01-01

The evolution of the charge state distribution of fast ions inside a solid is of basic interest in various research fields as stopping power measurements etc. The existing models for the charge state evolution differ in the treatment of the projectile-exit-surface interaction, which has a strong influence on the final charge state distributions. We measured the charge state distributions for C + , N + , and O + (30≤E/M≤130 keV/u) impact on thin C, Cu, and Au foils, where the surface properties were modified by sputter cleaning. The mesurements show a pronounced change of the mean projectile charge state to lower values in the case of sputter cleaned surfaces. This result underlines the importance of the projectile-surface interaction for the generation of the outcoming charge state distribution. (orig.)

Experiments on the indirect heating of low density aerogels for applications in heavy ion stopping in plasma

International Nuclear Information System (INIS)

Rosmej, O.N.; Blazevic, A.; Suslov, N.; Kunin, A.; Pinegin, A.; Schaefer, D.; Nisius, Th.; Zhao, Y.; Rinecker, T.; Wiechula, J.

2010-01-01

Complete text of publication follows. The unique combination of a Petawatt High-Energy Laser System for Ion beam eXperiments - 'Phelix' (Nd:glass, 1053 nm, 300-500 J, 1-15 ns) and intense heavy ion beams of the UNILAC accelerator at GSI-Darmstadt allow creating and probing of hot plasma with a density of some percentage of solid-state density. The experimental program aims at the investigation of fundamental features of heavy ion stopping in ionized matter in view of promising applications for the Heavy Ion Fusion and astrophysics. For combined experiments on the interaction of heavy ion beams with ionized matter (GSI) a high density plasma target with homogeneous in time (∼ 5 ns) and space (∼ 1 mm) plasma parameters in required. For these purposes we are developing the combined target which consists on the Gold hohlraum (converter) and low Z foam target heated by the hohlraum radiation before probed by an ion bunch. Foam targets are rather promising due to the effective conversion of the deposited radiation energy into the internal plasma energy and slow hydrodynamic response on the heating. Direct irradiation of the Gold converter walls with a nanosecond pulse delivered by the PHELIX-laser system (GSI) leads to hohlraum radiation spectra in the photon energy range of 50-500 eV. Expected temperatures of the foam targets heated by this radiation amount to 20-30 eV at electron densities of 10 21 cm -3 . The results of the last hohlraum experiments carried out at PHELIX-laser energies of 200-250 J will be presented. In experiments the hohlraum radiation field, the conversion efficiency of the laser energy into soft X-rays, duration of the soft X-ray pulse, and parameters of the heated with X-rays foam targets have been measured. Acknowledgements. This work is supported by ISTC 2264 grant.

Ion-assisted sputter deposition of molybdenum--silicon multilayers

International Nuclear Information System (INIS)

Vernon, S.P.; Stearns, D.G.; Rosen, R.S.

1993-01-01

X-ray multilayer (ML) structures that are fabricated by the use of magnetron-sputter deposition exhibit a degradation in structural quality as the deposition pressure is increased. The observed change in morphology is attributed to a reduced mobility of surface adsorbed atoms, which inhibits the formation of smooth, continuous layers. The application of a negative substrate bias produces ion bombardment of the growing film surface by sputtering gas ions extracted from the plasma and permits direct control of the energy density supplied to the film surface during thin-film growth. The technique supplements the energy lost to thermalization in high-pressure deposition and permits the fabrication of high-quality ML structures at elevated processing pressures. A threefold improvement in the soft-x-ray normal-incidence reflectance at 130 A results for substrate bias voltages of the order of ∼-150 V for Mo--Si ML's deposited at 10-mTorr Ar

Transversely Excited Atmospheric CO2 Laser-Induced Plasma Spectroscopy for the Detection of Heavy Metals in Soil

Science.gov (United States)

Khumaeni, A.; Sugito, H.; Setia Budi, W.; Yoyo Wardaya, A.

2018-01-01

A rapid detection of heavy metals in soil was presented by the metal-assisted gas plasma method using specific characteristics of a pulsed, transversely excited atmospheric (TEA) CO2 laser. The soil particles were placed in a hole made of acrylic plate. The sample was covered by a to prevent the soil particles from being blown off. The mesh also functioned to initiate a luminous plasma. When a TEA CO2 laser (1500 mJ, 200 ns) was focused on the soil sample, passing through the metal mesh, some of the laser energy was used to generate the gas plasma on the mesh surface, and the remaining laser energy was employed to ablate the soil particles. The fine, ablated soil particles moved into the gas plasma region to be dissociated and excited. Using this technique, analysis can be made with reduced sample pretreatment, and therefore a rapid analysis can be performed efficiently. The results proved that the signal to noise ratio (S/N) of the emission spectral lines is much better for the case of the present method (mesh method) compared to the case of standard laser-induced breakdown spectroscopy using the pellet method. Rapid detection of heavy metal elements in soil has been successfully carried out. The detection limits of Cu and Hg in soil were estimated to be 3 and 10 mg/kg, respectively. The present method has good potential for rapid and sensitive detection of heavy metals in soil samples.

Discharge Characteristic of VHF-DC Superimposed Magnetron Sputtering System

Science.gov (United States)

Toyoda, Hirotaka; Fukuoka, Yushi; Fukui, Takashi; Takada, Noriharu; Sasai, Kensuke

2014-10-01

Magnetron plasmas are one of the most important tools for sputter deposition of thin films. However, energetic particles from the sputtered target such as backscattered rare gas atoms or oxygen negative ions from oxide targets sometimes induce physical and chemical damages as well as surface roughening to the deposited film surface during the sputtering processes. To suppress kinetic energy of such particles, superposition of RF or VHF power to the DC power has been investigated. In this study, influence of the VHF power superposition on the DC target voltage, which is important factor to determine kinetic energy of high energy particles, is investigated. In the study, 40 MHz VHF power was superimposed to an ITO target and decrease in the target DC voltage was measured as well as deposited film deposition properties such as deposition rate or electrical conductivity. From systematic measurement of the target voltage, it was revealed that the target voltage can be determined by a very simple parameter, i.e., a ratio of VHF power to the total input power (DC and VHF powers) in spite of the DC discharge current. Part of this work was supported by ASTEP, JST.

Investigation of Plasma Facing Components in Plasma Focus Operation

Science.gov (United States)

Roshan, M. V.; Babazadeh, A. R.; Kiai, S. M. Sadat; Habibi, H.; Mamarzadeh, M.

2007-09-01

Both aspects of the plasma-wall interactions, counter effect of plasma and materials, have been considered in our experiments. The AEOI plasma focus, Dena, has Filippov-type electrodes. The experimental results verify that neutron production increases using tungsten as an anode insert material, compared to the copper one. The experiments show decrement of the hardness of Aluminum targets outward the sides, from 135 to 78 in Vickers scale. The sputtering yield is about 0.0065 for deuteron energy of 50 keV.

Experimental investigation of the energy and temperature dependence of beryllium self sputtering

International Nuclear Information System (INIS)

Korshunov, S.N.; Guseva, M.I.; Stolijarova, V.G.

1995-01-01

The low-Z metal beryllium is considered as plasma facing material (PFM) for the ITER. It is expected that operation temperature range of beryllium PFM will be (670 - 1070) K. While experimental Be-sputtering data bases exist for H + , D + and He + -ions, the self-sputtering yields of Be have only been estimated by computer simulation. In this paper we report the experimental results on the energy and temperature dependence of the beryllium self-sputtering yield (S). The energy dependence of S s in the energy range (0.5 - 10.0) keV was measured at 670 K. The self-sputtering yield of Be attains its maximal value at the ion energy of 1.5 keV, being equal to 0.32 ± at./ion. Comparison of the experimental results and theoretical prediction shows a good agreement for energy dependence of S s . The temperature dependence of S s in the temperature range (370-1070)K was obtained for 0.9keV Be + -ions. The value of S s is not changed up to 870 K. It sharply increases at the temperatures above 870 attaining the value of 0.75 at./ion at 1070 K

Structural and optical properties of titanium dioxide films deposited by reactive magnetron sputtering in pure oxygen plasma

International Nuclear Information System (INIS)

Asanuma, T.; Matsutani, T.; Liu, C.; Mihara, T.; Kiuchi, M.

2004-01-01

Titanium dioxide (TiO 2 ) thin films were deposited on unheated quartz (SiO 2 ) substrates in 'pure oxygen' plasma by reactive radio-frequency (rf) magnetron sputtering. The structural and optical properties of deposited films were systematically studied by changing the deposition parameters, and it was very recently found that crystalline TiO 2 films grew effectively in pure O 2 atmosphere. For TiO 2 films deposited at a rf power P rf of 200 W, x-ray diffraction patterns show the following features: (a) no diffraction peak was observed at a total sputtering pressure p tot of 1.3 Pa; (b) rutile (110) diffraction was observed at 4.0 Pa, (c) the dominant diffraction was from anatase (101) planes, with additional diffraction from (200), under p tot between 6.7 and 13 Pa. For the deposition at 140 W, however, crystalline films with mixed phases were observed only between 4.0 and 6.7 Pa. The peaks of both the deposition rate and the anatase weight ratio for the films produced at 140 W were found at p tot of approximately 6.7 Pa. This suggests that the nucleation and growth of TiO 2 films were affected by the composition, density, and kinetic energy of the particles impinging on the substrate surface. The optical absorption edge analysis showed that the optical band gap E g and the constant B could sensitively detect the film growth behavior, and determine the film structure and optical absorption. The change in the shape of the fundamental absorption edge is considered to reflect the variation of density and the short-range structural modifications

Measurement of the energy loss of heavy ions in laser-produced plasmas

Energy Technology Data Exchange (ETDEWEB)

Knobloch-Maas, Renate

2009-11-25

The interaction of ions with plasma is not yet fully understood today, although it is important for inertial fusion technology. During recent years, the energy loss of heavy ions in plasma has therefore been a subject of research in the Laser and Plasma Physics group of Darmstadt University of Technology. Several experiments were carried out at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt using laser-created plasma, thereby taking advantage of the unique combination of GSI's accelerator facility and the laser system nhelix, which is also described in this work. The experiments focus on the measurement of the energy loss of medium heavy ions in a plasma created by directly heating a thin carbon foil with the nhelix laser, at an energy of about 50 J. In order to measure the energy loss using a time-of-flight method, a stop detector is used to register the arrival of the ion pulses after passing the plasma and a 12 m drift space. At the beginning of the work on this thesis, the ion detector types formerly used were found to be inadequately suited to the difficult task; this was changed during this thesis. The ion detector has to be able to temporarily resolve ion pulses with a frequency of 108 MHz and a width (FWHM) of 3 ns at a very low current. It also has to withstand the X-ray burst from the plasma with a dead time shorter than the difference between the X-ray and the ion time of flight between the plasma and the detector. In order to satisfy these and other demands, a new diamond detector was designed and has now been used for several measurements. In addition to the new detector, other improvements were made concerning the diagnostics and the laser. The laser-created plasma now reaches a maximum temperature exceeding 200 eV and a free electron density of up to 10{sup 22} cm{sup -3}. With this greatly improved setup, energy loss data could be obtained with a temporal resolution several times better than before, using an ion beam with a

Measurement of the energy loss of heavy ions in laser-produced plasmas

International Nuclear Information System (INIS)

Knobloch-Maas, Renate

2009-01-01

The interaction of ions with plasma is not yet fully understood today, although it is important for inertial fusion technology. During recent years, the energy loss of heavy ions in plasma has therefore been a subject of research in the Laser and Plasma Physics group of Darmstadt University of Technology. Several experiments were carried out at the Gesellschaft fuer Schwerionenforschung (GSI) in Darmstadt using laser-created plasma, thereby taking advantage of the unique combination of GSI's accelerator facility and the laser system nhelix, which is also described in this work. The experiments focus on the measurement of the energy loss of medium heavy ions in a plasma created by directly heating a thin carbon foil with the nhelix laser, at an energy of about 50 J. In order to measure the energy loss using a time-of-flight method, a stop detector is used to register the arrival of the ion pulses after passing the plasma and a 12 m drift space. At the beginning of the work on this thesis, the ion detector types formerly used were found to be inadequately suited to the difficult task; this was changed during this thesis. The ion detector has to be able to temporarily resolve ion pulses with a frequency of 108 MHz and a width (FWHM) of 3 ns at a very low current. It also has to withstand the X-ray burst from the plasma with a dead time shorter than the difference between the X-ray and the ion time of flight between the plasma and the detector. In order to satisfy these and other demands, a new diamond detector was designed and has now been used for several measurements. In addition to the new detector, other improvements were made concerning the diagnostics and the laser. The laser-created plasma now reaches a maximum temperature exceeding 200 eV and a free electron density of up to 10 22 cm -3 . With this greatly improved setup, energy loss data could be obtained with a temporal resolution several times better than before, using an ion beam with a diameter of only

A hybrid electron cyclotron resonance metal ion source with integrated sputter magnetron for the production of an intense Al{sup +} ion beam

Energy Technology Data Exchange (ETDEWEB)

Weichsel, T., E-mail: tim.weichsel@fep.fraunhofer.de; Hartung, U.; Kopte, T. [Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, 01277 Dresden (Germany); Zschornack, G. [Institute of Solid State Physics, Dresden University of Technology, 01062 Dresden, Germany and Helmholtz-Zentrum Dresden-Rossendorf e.V., Institute of Ion Beam Physics and Materials Research, Dresden (Germany); Kreller, M.; Philipp, A. [DREEBIT GmbH, 01900 Grossroehrsdorf (Germany)

2015-09-15

A metal ion source prototype has been developed: a combination of magnetron sputter technology with 2.45 GHz electron cyclotron resonance (ECR) ion source technology—a so called magnetron ECR ion source (MECRIS). An integrated ring-shaped sputter magnetron with an Al target is acting as a powerful metal atom supply in order to produce an intense current of singly charged metal ions. Preliminary experiments show that an Al{sup +} ion current with a density of 167 μA/cm{sup 2} is extracted from the source at an acceleration voltage of 27 kV. Spatially resolved double Langmuir probe measurements and optical emission spectroscopy were used to study the plasma states of the ion source: sputter magnetron, ECR, and MECRIS plasma. Electron density and temperature as well as Al atom density were determined as a function of microwave and sputter magnetron power. The effect of ECR heating is strongly pronounced in the center of the source. There the electron density is increased by one order of magnitude from 6 × 10{sup 9} cm{sup −3} to 6 × 10{sup 10} cm{sup −3} and the electron temperature is enhanced from about 5 eV to 12 eV, when the ECR plasma is ignited to the magnetron plasma. Operating the magnetron at constant power, it was observed that its discharge current is raised from 1.8 A to 4.8 A, when the ECR discharge was superimposed with a microwave power of 2 kW. At the same time, the discharge voltage decreased from about 560 V to 210 V, clearly indicating a higher plasma density of the MECRIS mode. The optical emission spectrum of the MECRIS plasma is dominated by lines of excited Al atoms and shows a significant contribution of lines arising from singly ionized Al. Plasma emission photography with a CCD camera was used to prove probe measurements and to identify separated plasma emission zones originating from the ECR and magnetron discharge.

Erosion/redeposition analysis : status of modeling and code validation for semi-detached tokamak edge plasmas

International Nuclear Information System (INIS)

Brooks, J. N.

1999-01-01

We are analyzing erosion and tritium codeposition for ITER, DIII-D, and other devices with a focus on carbon divertor and metallic wall sputtering, for detached and semi-detached edge plasmas. Carbon chemical-sputtering hydrocarbon-transport is computed in detail using upgraded models for sputtering yields, species, and atomic and molecular processes. For the DIII-D analysis this includes proton impact and dissociative recombination for the full methane and higher hydrocarbon chains. Several mixed material (Si-C doping and Be/C) effects on erosion are examined. A semi-detached reactor plasma regime yields peak net wall erosion rates of ∼1.0 (Be), ∼0.3 (Fe), and ∼0.01 (W) cm/burn-yr, and ∼50 cm/burn-yr for a carbon divertor. Net carbon erosion is dominated by chemical sputtering in the ∼1-3 eV detached plasma zone. Tritium codeposition in divertor-sputtered redeposited carbon is high (∼10-20 g-T/1000 s ). Silicon and beryllium mixing tends to reduce carbon erosion. Initial hydrocarbon transport calculations for the DIII-D DiMES-73 detached plasma experiment show a broad spectrum of redeposited molecules with ∼90% redeposition fraction

Sputtering of copper atoms by keV atomic and molecular ions A comparison of experiment with analytical and computer based models

CERN Document Server

Gillen, D R; Goelich,

2002-01-01

Non-resonant multiphoton ionisation combined with quadrupole and time-of-flight analysis has been used to measure energy distributions of sputtered copper atoms. The sputtering of a polycrystalline copper target by 3.6 keV Ar sup + , N sup + and CF sub 2 sup + and 1.8 keV N sup + and CF sub 2 sup + ion bombardment at 45 deg. has been investigated. The linear collision model in the isotropic limit fails to describe the high energy tail of the energy distributions. However the TRIM.SP computer simulation has been shown to provide a good description. The results indicate that an accurate description of sputtering by low energy, molecular ions requires the use of computer simulation rather than analytical approaches. This is particularly important when considering plasma-surface interactions in plasma etching and deposition systems.

Study of the chemical sputtering in Tore-Supra; Etude de l'erosion chimique dans le tokamak Tore-Supra

Energy Technology Data Exchange (ETDEWEB)

Cambe, A

2002-06-28

The work presented in this thesis focuses on the interactions between energetic particles coming from thermonuclear plasma and the inner components of a fusion machine. This interaction induces two major problems: erosion of the wall, and tritium retention. This report treats the erosion of carbon based materials. The first part is devoted to chemical sputtering, that appears to be the principal erosion mechanism, compared to physical sputtering and radiation enhanced sublimation that both can be limited. Chemical sputtering has been studied in situ in the tokamak Tore-Supra for ohmic and lower hybrid (LH) heated discharges, by means of mass spectrometry and optical spectroscopy. We have shown that it is necessary to take into account both methane and heavier hydrocarbons (C{sub 2}D{sub x} and C{sub 3}D{sub y}) in the determination of the chemical sputtering yield. It is found that for the ohmic discharges, the sputtering yield of CD{sub 4} (Y{sub CD4}) is highly flux ({phi}) dependent, showing a variation of the form: Y{sub CD4} {proportional_to} {phi}{sup -0.23}. The experimental study also reveals that an increase of the surface temperature induces an augmentation of Y{sub CD4}. The interpretation and the modelling of the experimental results have been performed with a Monte Carlo code (BBQ. In the second part of this work, we have developed and installed an infrared spectroscopy diagnostic in the 0.8-1.6, {mu}m wavelength range dedicated to the measurement of surface temperature, and the identification of atomic and molecular lines emitted during plasma/wall interactions. In the third part, we present the feasibility study of an in situ tungsten deposition process at low temperature(<80 deg C) in order to suppress the chemical sputtering. This study shows that, with this method call Plasma Assisted Chemical Vapor Deposition (PACVD), we are able to coat the whole inner vessel of a tokamak with 1 {mu}m of tungsten. (author)

TiO2 thin and thick films grown on Si/glass by sputtering of titanium targets in an RF inductively coupled plasma

International Nuclear Information System (INIS)

Valencia-Alvarado, R; López-Callejas, R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

2015-01-01

TiO 2 thin and thick films were deposited on silicon/glass substrates using RF inductive plasma in continuous wave. The films thickness, as well as phases control, is achieved with a gradual increase in temperature substrates varying supplied RF power or working gas pressure besides deposition time as well. The deposition conditions were: argon 80%/oxygen 20% carefully calibrated mixture of 2 to 7×10 −2 mbar as working gas pressure range. Deposition time 0.5 to 5 hours, 500 or 600 W RF power at 13.56 MHz frequency and 242-345 °C substrates temperature range. The titanium dioxide deposited on the substrates is grown by sputtering of a titanium target negatively polarized at 3-5 kV DC situated 14 mm in front of such substrates. The plasma reactor is a simple Pyrex-like glass cylindrical vessel of 50 cm long and 20 cm in diameter. Using the before describe plasma parameters we obtained films only anatase and both anatase/rutile phases with stoichiometric different. The films were characterized by X-ray photoelectron spectroscopy (XPS), stylus profilometer, X-ray diffraction (XRD), scanning electron microscopy (SEM) and Raman spectroscopy. (paper)

Helicon plasma potential measurements using a heavy ion beam probe

International Nuclear Information System (INIS)

P. Schoch; K. Connor; J. Si

2005-01-01

A Heavy Ion Beam Probe, HIBP, has been installed on a helicon plasma device. The objective was to measure plasma fluctuations at the 13.55MHz RF frequency. This offers a unique challenge for the HIBP, because the transit time of the probing ion is long compared to the fluctuations of interest. For previous HIBPs, the transit time has been short compared to the period of the fluctuations which permits one to assume that the magnetic and electric fields are static. Modeling has shown that the diagnostic will still accurately measure the average potential. The fluctuating potential was to be detected but the absolute magnitude is difficult to determine with signal from a single point. However, modeling indicates multipoint measurements will allow one to resolve the absolute fluctuation magnitude. Work supported by DOE Grant No. DE-FG02-99ER5452985 During the funding of this grant, a helicon plasma discharge device was built and operated. A Heavy Ion Beam Probe primary system was installed and operated. A primary beam detector was installed and primary beam was detected both with and without plasma. Attempts were made to detect secondary ions using the primary beam detector, without success. Given the lack of a detectable signal, the energy analyzer of the HIBP system was never installed. It is available for installation if there is a reason to do so in the future. Analysis of the system indicated that the plasma electron temperature, estimated to be a few eV, was the likely reason for the lack of detectable secondary ions. A change of ion species to either Boron or Magnesium would greatly increase the signal, but neither of these ions have been used in a HIBP system. The ion source used in this system is made by using a charge exchange process to create a zeolite loaded with the desired ion. Attempts were made to use charge exchange to load Magnesium into a zeolite, and were not successful. It is felt that Magnesium and/or Boron zeolite sources could be created, but

Effects of density asymmetries on heavy-impurity transport in a rotating tokamak-plasma

International Nuclear Information System (INIS)

Romanelli, M.; Ottaviani, M.

1997-12-01

The transport equations of heavy trace-impurities in a Tokamak plasma with strong toroidal rotation have been studied analytically in the collisional regime. It is found that the poloidal asymmetry of the impurity-density, which occurs because of the rotation, brings about a large enhancement of the diffusivity and indeed of the pinch velocity above the conventional Pfirsh-Schlueter values. (author)

Suboxide/subnitride formation on Ta masks during magnetic material etching by reactive plasmas

Energy Technology Data Exchange (ETDEWEB)

Li, Hu; Muraki, Yu; Karahashi, Kazuhiro; Hamaguchi, Satoshi, E-mail: hamaguch@ppl.eng.osaka-u.ac.jp [Center for Atomic and Molecular Technologies, Osaka University, Yamadaoka 2-1, Suita 565-0871 (Japan)

2015-07-15

Etching characteristics of tantalum (Ta) masks used in magnetoresistive random-access memory etching processes by carbon monoxide and ammonium (CO/NH{sub 3}) or methanol (CH{sub 3}OH) plasmas have been examined by mass-selected ion beam experiments with in-situ surface analyses. It has been suggested in earlier studies that etching of magnetic materials, i.e., Fe, Ni, Co, and their alloys, by such plasmas is mostly due to physical sputtering and etch selectivity of the process arises from etch resistance (i.e., low-sputtering yield) of the hard mask materials such as Ta. In this study, it is shown that, during Ta etching by energetic CO{sup +} or N{sup +} ions, suboxides or subnitrides are formed on the Ta surface, which reduces the apparent sputtering yield of Ta. It is also shown that the sputtering yield of Ta by energetic CO{sup +} or N{sup +} ions has a strong dependence on the angle of ion incidence, which suggests a correlation between the sputtering yield and the oxidation states of Ta in the suboxide or subnitride; the higher the oxidation state of Ta, the lower is the sputtering yield. These data account for the observed etch selectivity by CO/NH{sub 3} and CH{sub 3}OH plasmas.

Characteristics of ITO electrode grown by linear facing target sputtering with ladder type magnetic arrangement for organic light emitting diodes

International Nuclear Information System (INIS)

Jeong, Jin-A; Kim, Han-Ki; Lee, Jae-Young; Lee, Jung-Hwan; Bae, Hyo-Dae; Tak, Yoon-Heung

2009-01-01

The preparation and characteristics of indium tin oxide (ITO) electrodes grown using a specially designed linear facing target sputtering (LFTS) system with a ladder type magnet arrangement for organic light emitting diodes (OLED) are described. It was found that the electrical and optical properties of the ITO electrode were critically dependent on the Ar/O 2 flow ratio, while its structural and surface properties remained fairly constant regardless of the Ar/O 2 flow ratio, due to the low substrate temperature during the plasma damage-free sputtering. Under the optimized conditions, we obtained an ITO electrode with the lowest sheet resistance of 39.4 Ω/sq and high transmittance of 90.1% (550 nm wavelength) at room temperature. This suggests that LFTS is a promising low temperature and plasma damage free sputtering technology for preparing high-quality ITO electrodes for OLEDs and flexible OLEDs at room temperature.

Sputtering. [as deposition technique in mechanical engineering

Science.gov (United States)

Spalvins, T.

1976-01-01

This paper primarily reviews the potential of using the sputtering process as a deposition technique; however, the manufacturing and sputter etching aspects are also discussed. Since sputtering is not regulated by classical thermodynamics, new multicomponent materials can be developed in any possible chemical composition. The basic mechanism for dc and rf sputtering is described. Sputter-deposition is described in terms of the unique advantageous features it offers such as versatility, momentum transfer, stoichiometry, sputter-etching, target geometry (coating complex surfaces), precise controls, flexibility, ecology, and sputtering rates. Sputtered film characteristics, such as strong adherence and coherence and film morphology, are briefly evaluated in terms of varying the sputtering parameters. Also described are some of the specific industrial areas which are turning to sputter-deposition techniques.

Deposition of thin films by magnetron sputtering molybdenum in samples of pure copper; Deposicao de filmes finos de molibdenio por magnetron sputtering em amostra de cobre puro

Energy Technology Data Exchange (ETDEWEB)

Ferreira, N.M.; Almeida, E.O. de; Alves Junior, C. [Universidade Federal do Rio Grande do Norte, Campus Universitario Lagoa Nova, PPGCEM - Natal, RN (Brazil); Lourenco, J.M. [Instituto Federal de Educacao, Ciencias e Tecnologia do Rio Grande do Norte (IFRN), Natal, RN (Brazil)

2010-07-01

The deposition surface is a process of thermochemical treatment, which involves the deposition of a thin film usually about one to two microns on a metallic substrate, which constitutes one of the most important surface engineering techniques. The plasma deposition process with the configuration of magnetron sputtering it is removing material from a solid surface (target) through the impact of energetic particles from plasma. The aim of this study is to characterize the microstructure of the material under study using the techniques of optical microscopy and scanning electron microscopy. (author)

Analysis of the plasma impurity influx from alkali-metal coatings for fusion-reactor applications

International Nuclear Information System (INIS)

DeWald, A.B.; Davidson, J.N.; Krauss, A.R.; Gruen, D.M.

1982-01-01

Recently, it has been proposed that alkali-metal covered surfaces be applied to magnetic fusion devices as a means of controlling plasma impurity contamination and shielding the substrate from erosion. Monolayer films of alkali metals have been shown to sputter primarily as ions under particle bombardment. Thus, it is thought that a sheath potential and/or magnetic fields encountered by a sputtered ion will return the ion to the surface without entering the plasma. In this paper, we investigate the net wall impurity influx associated with coatings which exhibit substantial secondary ion emission as compared to those which sputter only as neutral atoms. Included in the analysis are sputtered substrate atoms. These are sometimes found to be a significant fraction of the total sputtering yield for low-Z alkali monolayers and affect the overall performance of such coatings. Estimates of the impurity influx made in the neighborhood of a sheath potential show that secondary-ion emitting coatings are effective as a means of inhibiting plasma impurity contamination and wall erosion

Effect of sputtering power on structure and properties of Bi film deposited by DC magnetron sputtering

International Nuclear Information System (INIS)

Liao Guo; He Zhibing; Xu Hua; Li Jun; Chen Taihua; Chen Jiajun

2012-01-01

Bi film was fabricated at different sputtering powers by DC magnetron sputtering. The deposition rate of Bi film as the function of sputtering power was studied. The surface topography of Bi film was observed by SEM, and the growth mode of Bi film was investigated. The crystal structure was analyzed by XRD. The grain size and stress of Bi film were calculated. The SEM images show that all the films are columnar growth. The average grain size firstly increases as the sputtering power increases, then decreases at 60 W. The film becomes loose with the increase of sputtering power, while, the film gets compact when the sputtering power becomes from 45 to 60 W. The XRD results show that films are polycrystalline of hexagonal. And the stress transforms from the tensile stress to compressive stress as the sputtering power increases. (authors)

Heavy ion beam probe investigations of plasma potential in ECRH and NBI in the TJ-II stellarator

International Nuclear Information System (INIS)

Melnikov, A.V.; Eliseev, L.; Perfilov, S.V.; Chmyga, A.A.; Dreval, N.; Khrebtov, S.M.; Komarov, A.D.; Kozachok, A.S.; Krupnik, L.; Alonso, A.; Pablos, J.L. de; Cappa, A.; Fernandez, A.; Fuentes, C.; Hidalgo, C.; Liniers, M.; Pedrosa, M.A.

2005-01-01

Direct measurements of electric potential and its fluctuations are of a primary importance in magnetic confinement systems. The Heavy Ion Beam Probe (HIBP) diagnostic is used in TJ-2 stellarator to study directly plasma electric potential profiles with spatial (up to 1cm) and temporal (up to 10 ∝s) resolution. The singly charged heavy ions Cs + with energies up to 125 keV are used to probe the plasma column from the edge to the core. Both ECRH and NBI heated plasmas (P ECRH = 200 - 400kW, P NBI = 400kW, E NBI = 28 kV) were studied. The significant improvement in the HIBP beam control system and the acquisition electronics leads us to increase the possibilities of the diagnostic. The most crucial one is the extension of the signal dynamic range, which allows us to have the reliable profiles from the plasma center to the plasma edge both in the high and low field side regions. Low density ECRH (n = 0.5-1.1.10 13 cm -3 ) plasmas in TJ-2 are characterised by core positive plasma potential of order of 500 - 1000 V and positive electric fields up to 50 V/cm. Edge radial electric fields remain positive at low densities and became negative at the threshold density that depends of plasma configuration. NBI plasmas are characterized by negative electric potential in the full plasma column and negative radial electric fields (in the range of 10 - 40 V/cm). The density rise during the NBI phase is accompanied by the decay of core plasma potential. When density is getting the level of n ∼ 2.0.10 13 cm -3 , the potential stops its evolution and remains constant. The evolution of plasma potential near density limit is under investigation. These observations, reported in different magnetic configurations, show the clear link between plasma potential and plasma density. (author)

Dynamics of plasma ions motion in ultra-intense laser-excited plasma wakes

International Nuclear Information System (INIS)

Zhou Suyun; Li Jing

2013-01-01

The effects of heavy ions and protons motion in an ultra-intense laser-driven plasma wake are compared by rebuilding a plasma wake model. It is shown that with the same laser and plasma background electron density n 0 , the heavy ions' motion suppresses wake-field resonant excitation less than the protons' motion in their own plasma wake. Though heavy ions obtain more kinetic energy from the plasma wake, its energy density is less than that of the protons due to the ion density being far less than the proton density. As a result, the total energy of heavy ions obtained from the wake-field is far less than that of protons. The dependence of the kinetic energy and the energy density of protons and heavy ions on n 0 is discussed. (paper)

Plasma streams mixing in two-channel t-shaped magnetic filter

International Nuclear Information System (INIS)

Aksyonov, D.S.; Aksenov, I.I.; Luchaninov, A.A.; Reshetnyak, E.N.; Strel'nitskij, V.E.

2011-01-01

Ti-Al-N films were deposited by vacuum arc method. T-shaped magnetic filter with two channels was used for films preparation. Deposition was performed after aluminum and titanium separate plasma streams from two plasma sources were mixed into single one inside plasma duct having weakened magnetic field near its output. Obtained films have uniform distribution of composition and thickness on 180 mm diameter substrate surface. It was found that mixing and homogenization degree depends on nitrogen pressure, output magnetic field intensity and output- to-substrate distance. Film self-sputtering and aluminum preferential sputtering were observed for elevated negative substrate bias potentials.

Ambient-temperature fabrication of microporous carbon terminated with graphene walls by sputtering process for hydrogen storage applications

International Nuclear Information System (INIS)

Banerjee, Arghya Narayan; Joo, Sang Woo; Min, Bong-Ki

2013-01-01

A very thin amorphous carbon film (10–30 nm), has been bombarded with sputtered Cr nanoparticles, resulting in inelastic collision between the nanoparticles and the nuclei of the C-atoms causing atom displacement and re-arrangement into graphene layers. The process occurs at ambient temperature. Fabrication of graphitic microporous carbon terminated with few-to-multilayer graphene walls has been verified by Raman spectroscopy and scanning transmission electron microscopy. High resolution transmission electron micrographs reveal that the formation of graphene layers is highly sensitive to the sputtering parameters. With a gradual increase in the sputtering voltage/current density/time from 3.5 kV/40 mA–cm −2 /1.0 min to 5.0 kV/70 mA–cm −2 /3.0 min the graphitic domains are found to transform from semi-graphitized layers to well-defined, highly ordered, larger-area graphene walls within the microporous network. The mechanism of this graphitic microporous carbon formation is assumed to be due to two simultaneous processes: in one hand, the sputtering plasma, containing energetic ions and sub-atomic particles, act as dry-etchant to activate the a:C film to transform it into microporous carbon, whereas on the other hand, the charged metal nanoparticle/ion bombardment under sputtering resulted in the inelastic collision between the nanoparticles/ions and the nuclei of the C atoms followed by atom displacement (and displacement cascade) and re-arrangement into ordered structure to form graphitic domains within the microporous carbon network. H 2 storage experiment of the samples depicts excellent hydrogen storage properties. This simple, cost-effective, complementary-metal-oxide-semiconductor-compatible, single-step process of metal-graphene hybrid nanomaterial formation may find interesting applications in the field of optoelectronics and biotechnology. Additionally, this method can be adopted easily for the incorporation of transition metals into graphene and

ECR plasma source for heavy ion beam charge neutralization

Science.gov (United States)

Efthimion, Philip C.; Gilson, Erik; Grisham, Larry; Kolchin, Pavel; Davidson, Ronald C.; Yu, Simon; Logan, B. Grant

2003-01-01

Highly ionized plasmas are being considered as a medium for charge neutralizing heavy ion beams in order to focus beyond the space-charge limit. Calculations suggest that plasma at a density of 1 100 times the ion beam density and at a length [similar]0.1 2 m would be suitable for achieving a high level of charge neutralization. An Electron Cyclotron Resonance (ECR) source has been built at the Princeton Plasma Physics Laboratory (PPPL) to support a joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization with plasma. The ECR source operates at 13.6 MHz and with solenoid magnetic fields of 1 10 gauss. The goal is to operate the source at pressures [similar]10[minus sign]6 Torr at full ionization. The initial operation of the source has been at pressures of 10[minus sign]4 10[minus sign]1 Torr. Electron densities in the range of 108 to 1011 cm[minus sign]3 have been achieved. Low-pressure operation is important to reduce ion beam ionization. A cusp magnetic field has been installed to improve radial confinement and reduce the field strength on the beam axis. In addition, axial confinement is believed to be important to achieve lower-pressure operation. To further improve breakdown at low pressure, a weak electron source will be placed near the end of the ECR source. This article also describes the wave damping mechanisms. At moderate pressures (> 1 mTorr), the wave damping is collisional, and at low pressures (< 1 mTorr) there is a distinct electron cyclotron resonance.

Improvement of dielectric properties of BLT thin films deposited by magnetron sputtering

Energy Technology Data Exchange (ETDEWEB)

Besland, M P; Barroy, P R J; Richard-Plouet, M; Tessier, P Y; Brohan, L; Djouadi, M A [Universite de Nantes - Institut des Materiaux Jean Rouxel, UMR CNRS 6502, 2, rue de la Houssiniere BP32229, 44322 Nantes Cedex (France); Borderon, C; Tacon, S Le; Averty, D; Gundel, H W [Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique, UPRES-EA 1770, IREENA, Universite de Nantes, 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex (France)], E-mail: Marie-Paule.Besland@cnrs-imn.fr

2008-01-15

Well crystallized BLT thin films were deposited by RF magnetron sputtering using a target of Aurivillius phase Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12}(BLT{sub 0,75}), elaborated in our institute. RF sputtering experiments were performed at room temperature with an argon/oxygen mixture, in a pressure range of 20-50 mTorr. Optimisation of the plasma parameters, namely deposition pressure, RF power and oxygen content in the gas phase, allows obtaining BLT films with a chemical composition close to Bi{sub 3.25}La{sub 0.75}Ti{sub 3}O{sub 12}. After ex-situ annealing under oxygen atmosphere at 650 deg. C, BLT films deposited on Pt/TiO{sub 2}/SiO{sub 2}/Si (multilayer) substrates exhibit well defined rod-like grains morphology. A two step deposition process appeared to be necessary in order to reach satisfying dielectric properties. The effect of the plasma parameters on the chemical composition and electrical properties are presented and discussed.

An analysis of the plasma impurity influx from alkali-metal coatings for fusion reactor applications

International Nuclear Information System (INIS)

DeWald, A.B.; Davidson, J.N.; Krauss, A.R.; Gruen, D.M.

1982-01-01

Recently, it has been proposed that alkali-metal covered surfaces be applied to magnetic fusion devices as a means of controlling plasma impurity contamination and shielding the substrate from erosion. Monolayer films of alkali metals have been shown to sputter primarily as ions under particle bombardment. Thus, it is thought that a sheath potential and/or magnetic fields encountered by a sputtered ion will return the ion to the surface without entering the plasma. In this paper, we investigate the net wall impurity influx associated with coatings which exhibit substantial secondary ion emission compared with those which sputter only as neutral atoms. Included in the analysis are sputtered substrate atoms. These are sometimes found to be a significant fraction of the total sputtering yield for low-Z alkali monolayers and affect the overall performance of such coatings. Estimates of the impurity influx made in the neighborhood of a sheath potential show that secondary-ion emitting coatings are effective as a means of inhibiting plasma impurity contamination and wall erosion. (orig.)

A global plasma model for reactive deposition of compound films by modulated pulsed power magnetron sputtering discharges

Science.gov (United States)

Zheng, B. C.; Wu, Z. L.; Wu, B.; Li, Y. G.; Lei, M. K.

2017-05-01

A spatially averaged, time-dependent global plasma model has been developed to describe the reactive deposition of a TiAlSiN thin film by modulated pulsed power magnetron sputtering (MPPMS) discharges in Ar/N2 mixture gas, based on the particle balance and the energy balance in the ionization region, and considering the formation and erosion of the compound at the target surface. The modeling results show that, with increasing the N2 partial pressure from 0% to 40% at a constant working pressure of 0.3 Pa, the electron temperature during the strongly ionized period increases from 4 to 7 eV and the effective power transfer coefficient, which represents the power fraction that effectively heats the electrons and maintains the discharge, increases from about 4% to 7%; with increasing the working pressure from 0.1 to 0.7 Pa at a constant N2 partial pressure of 25%, the electron temperature decreases from 10 to 4 eV and the effective power transfer coefficient decreases from 8% to 5%. Using the modeled plasma parameters to evaluate the kinetic energy of arriving ions, the ion-to-neutral flux ratio of deposited species, and the substrate heating, the variations of process parameters that increase these values lead to an enhanced adatom mobility at the target surface and an increased input energy to the substrate, corresponding to the experimental observation of surface roughness reduction, the microstructure transition from the columnar structure to the dense featureless structure, and the enhancement of phase separation. At higher N2 partial pressure or lower working pressure, the modeling results demonstrate an increase in electron temperature, which shifts the discharge balance of Ti species from Ti+ to Ti2+ and results in a higher return fraction of Ti species, corresponding to the higher Al/Ti ratio of deposited films at these conditions. The modeling results are well correlated with the experimental observation of the composition variation and the microstructure

On the phase formation of sputtered hafnium oxide and oxynitride films

International Nuclear Information System (INIS)

Sarakinos, K.; Music, D.; Mraz, S.; Baben, M. to; Jiang, K.; Nahif, F.; Braun, A.; Zilkens, C.; Schneider, J. M.; Konstantinidis, S.; Renaux, F.; Cossement, D.; Munnik, F.

2010-01-01

Hafnium oxynitride films are deposited from a Hf target employing direct current magnetron sputtering in an Ar-O 2 -N 2 atmosphere. It is shown that the presence of N 2 allows for the stabilization of the transition zone between the metallic and the compound sputtering mode enabling deposition of films at well defined conditions of target coverage by varying the O 2 partial pressure. Plasma analysis reveals that this experimental strategy facilitates control over the flux of the O - ions which are generated on the oxidized target surface and accelerated by the negative target potential toward the growing film. An arrangement that enables film growth without O - ion bombardment is also implemented. Moreover, stabilization of the transition sputtering zone and control of the O - ion flux without N 2 addition is achieved employing high power pulsed magnetron sputtering. Structural characterization of the deposited films unambiguously proves that the phase formation of hafnium oxide and hafnium oxynitride films with the crystal structure of HfO 2 is independent from the O - bombardment conditions. Experimental and theoretical data indicate that the presence of vacancies and/or the substitution of O by N atoms in the nonmetal sublattice favor the formation of the cubic and/or the tetragonal HfO 2 crystal structure at the expense of the monoclinic HfO 2 one.

An experiment on the dynamics of ion implantation and sputtering of surfaces

Energy Technology Data Exchange (ETDEWEB)

Wright, G. M.; Barnard, H. A.; Kesler, L. A.; Peterson, E. E.; Stahle, P. W.; Sullivan, R. M.; Whyte, D. G.; Woller, K. B. [Plasma Science and Fusion Center, MIT, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

2014-02-15

A major impediment towards a better understanding of the complex plasma-surface interaction is the limited diagnostic access to the material surface while it is undergoing plasma exposure. The Dynamics of ION Implantation and Sputtering Of Surfaces (DIONISOS) experiment overcomes this limitation by uniquely combining powerful, non-perturbing ion beam analysis techniques with a steady-state helicon plasma exposure chamber, allowing for real-time, depth-resolved in situ measurements of material compositions during plasma exposure. Design solutions are described that provide compatibility between the ion beam analysis requirements in the presence of a high-intensity helicon plasma. The three primary ion beam analysis techniques, Rutherford backscattering spectroscopy, elastic recoil detection, and nuclear reaction analysis, are successfully implemented on targets during plasma exposure in DIONISOS. These techniques measure parameters of interest for plasma-material interactions such as erosion/deposition rates of materials and the concentration of plasma fuel species in the material surface.

An experiment on the dynamics of ion implantation and sputtering of surfaces

International Nuclear Information System (INIS)

Wright, G. M.; Barnard, H. A.; Kesler, L. A.; Peterson, E. E.; Stahle, P. W.; Sullivan, R. M.; Whyte, D. G.; Woller, K. B.

2014-01-01

A major impediment towards a better understanding of the complex plasma-surface interaction is the limited diagnostic access to the material surface while it is undergoing plasma exposure. The Dynamics of ION Implantation and Sputtering Of Surfaces (DIONISOS) experiment overcomes this limitation by uniquely combining powerful, non-perturbing ion beam analysis techniques with a steady-state helicon plasma exposure chamber, allowing for real-time, depth-resolved in situ measurements of material compositions during plasma exposure. Design solutions are described that provide compatibility between the ion beam analysis requirements in the presence of a high-intensity helicon plasma. The three primary ion beam analysis techniques, Rutherford backscattering spectroscopy, elastic recoil detection, and nuclear reaction analysis, are successfully implemented on targets during plasma exposure in DIONISOS. These techniques measure parameters of interest for plasma-material interactions such as erosion/deposition rates of materials and the concentration of plasma fuel species in the material surface

Chemical degradation of selected Zn-based corrosion products induced by C{sub 60} cluster, Ar cluster and Ar{sup +} ion sputtering in the focus of X-ray photoelectron spectroscopy (XPS)

Energy Technology Data Exchange (ETDEWEB)

Steinberger, R., E-mail: roland.steinberger@jku.at [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterization, Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Sicking, J., E-mail: jens.sicking@bayer.com [Bayer AG, Engineering & Technology, Applied Physics, Chempark Building E 41, 51368 Leverkusen (Germany); Weise, J., E-mail: juliane.weise@physik.tu-freiberg.de [Institut für Experimentelle Physik, TU Bergakademie Freiberg, Leipziger Straße 23, 09599 Freiberg (Germany); Duchoslav, J., E-mail: jiri.duchoslav@jku.at [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterization, Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Greunz, T., E-mail: theresia.greunz@jku.at [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterization, Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria); Meyer, D.C., E-mail: Dirk-Carl.Meyer@physik.tu-freiberg.de [Institut für Experimentelle Physik, TU Bergakademie Freiberg, Leipziger Straße 23, 09599 Freiberg (Germany); Stifter, D., E-mail: david.stifter@jku.at [Christian Doppler Laboratory for Microscopic and Spectroscopic Material Characterization, Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Altenberger Straße 69, 4040 Linz (Austria)

2017-05-01

Highlights: • XPS investigations for various sputter concepts on Zn-based corrosions products. • Direct comparison of induced chemical damage for ion and cluster sputtering. • Azimuthal rotation or heavy projectile bombardment was not found to be beneficial. • Ar cluster etching is rated as unsuitable for surface cleaning or depth profiling. • C{sub 60} and Ar{sup +} are applicable for sputtering when degradation is carefully considered. - Abstract: Monoatomic ion sputtering is a common concept for surface sensitive analysis methods to clean surfaces prior investigation or to obtain information from deeper regions. However, severe damage of the materials – linked to preferential sputtering, ion implantation, atomic mixing and in worst case chemical degradation – can affect the validity of the analysis. Hence, the impact of C{sub 60} cluster etching, furthermore, of Ar{sup +} ion bombardment with and without azimuthal sample rotation and also the application of heavy projectiles (Xe{sup +} ions) was investigated to find a concept, which is less destructive or with less critical influence on the chemical nature of the investigated materials. In this work the focus is set on hydrozincite and zinc oxide, two common corrosion products of Zn-based coatings. As a main point, all the obtained results from (i) Ar{sup +} ion, (ii) Ar cluster, and (iii) C{sub 60} cluster etching on the degradation kinetics of hydrozincite were compared with respect to the reached sputter depth. In addition, the sputter rate of all three methods was experimentally determined for ZnO. In total, fully non-destructive conditions could not be found, but valuable knowledge on the type and rate of degradation, which is essential to choose the most suited sputter concept.

Enhanced oxidation of TiO.sub.2./sub. films prepared by high power impulse magnetron sputtering running in metallic mode

Czech Academy of Sciences Publication Activity Database

Straňák, V.; Kratochvíl, J.; Olejníček, Jiří; Kšírová, Petra; Sezemsky, P.; Čada, Martin; Hubička, Zdeněk

2017-01-01

Roč. 121, č. 17 (2017), s. 1-9, č. článku 171914. ISSN 0021-8979 R&D Projects: GA ČR(CZ) GA15-00863S Institutional support: RVO:68378271 Keywords : sputter deposition * plasma deposition * gas discharges * metallic thin films * probe plasma diagnostics Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.068, year: 2016

The statistics of sputtering

International Nuclear Information System (INIS)

Robinson, M.T.

1993-01-01

The MARLOWE program was used to study the statistics of sputtering on the example of 1- to 100-keV Au atoms normally incident on static (001) and (111) Au crystals. The yield of sputtered atoms was examined as a function of the impact point of the incident particles (''ions'') on the target surfaces. There were variations on two scales. The effects of the axial and planar channeling of the ions could be traced, the details depending on the orientation of the target and the energies of the ions. Locally, the sputtering yield was very sensitive to the impact point, small changes in position often producing large changes yield. Results indicate strongly that the sputtering yield is a random (''chaotic'') function of the impact point

Formation and stability of sputtered clusters

International Nuclear Information System (INIS)

Andersen, H.H.

1989-01-01

Current theory for the formation of sputtered clusters states that either atoms are sputtered individually and aggregate after having left the surface or they are sputtered as complete clusters. There is no totally sharp boundary between the two interpretations, but experimental evidence is mainly thought to favour the latter model. Both theories demand a criterion for the stability of the clusters. In computer simulations of sputtering, the idea has been to use the same interaction potential as in the lattice computations to judge the stability. More qualitatively, simple geometrical shapes have also been looked for. It is found here, that evidence for 'magic numbers' and electron parity effects in clusters have existed in the sputtering literature for a long time, making more sophisticated stability criteria necessary. The breakdown of originally sputtered metastable clusters into stable clusters gives strong support to the 'sputtered as clusters' hypothesis. (author)

Bibliography on plasma-wall interactions

International Nuclear Information System (INIS)

Okano, J.

1980-05-01

Bibliography is compiled for the following subjects: (1) Plasma-wall interactions, general, (2) Sputtering, (3) Chemical sputtering, (4) Blistering, (5) Electron-impact desorption, (6) Thermal desorption and photo-desorption, (7) Emission of secondary electrons and ions, emission of photoelectrons, and material for getters, (8) Gas release and trapping, (9) Approach from surface diagnostics (review). The compilation has not been intended to be complete, but to give a first step toward a further study of the respective subjects. (author)

Report on the workshop on atomic and plasma physics requirements for heavy ion fusion, Argonne National Lab., December 13-14, 1979

International Nuclear Information System (INIS)

Kin, Y.K.; Magelssen, G.

1979-01-01

Atomic, molecular, and plasma physics areas that are relevant to inertial confinement fusion by energetic heavy ions are identified. Discussions are confined to problems related to the design of heavy ion accelerators, accumulation of ions in storage rings, and the beam transport in a reactor vessel

Transport theory of sputtering I: Depth of origin of sputtered atoms

International Nuclear Information System (INIS)

Zhang, Z.L.

1999-01-01

Sputter theory employing a sum of two power cross sections has been implemented. Compared with the well known Lindhard power cross section (V∝r -1/m ), a sum of two such cross sections can give a much better approximation to the Born-Mayer scattering in the low energy region (m ∼ 0.1). By using both one and two power cross sections, we have solved the linear transport equations describing the sputtering problem asymptotically. As usual, electronic stopping is ignored in the analysis. It has further been proved that Falcone's theory of the atom ejection process contradicts transport theory. The Andersen-Sigmund relation for partial sputtering yield ratios between two elements in an arbitrary multicomponent target has been derived by both methods. The energy deposited in the target surface layers has been computed for a few typical ion-target combinations. The numerical curves show that both theories generate almost the same results (error <10%) for m=3D0.2. It is also shown that, if the sputtering yield equals the corresponding one in Sigmund's theory, the depth of origin of sputtered atoms must be shorter than in Sigmund's theory for 0.25 m ≥ 3D 0. The former even may be only about one half of the latter as long as m=3D0. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Time-resolved investigation of dual high power impulse magnetron sputtering with closed magnetic field during deposition of Ti-Cu thin films

International Nuclear Information System (INIS)

Stranak, Vitezslav; Hippler, Rainer; Cada, Martin; Hubicka, Zdenek; Tichy, Milan

2010-01-01

Time-resolved comparative study of dual magnetron sputtering (dual-MS) and dual high power impulse magnetron sputtering (dual-HiPIMS) systems arranged with closed magnetic field is presented. The dual-MS system was operated with a repetition frequency 4.65 kHz (duty cycle ≅50%). The frequency during dual-HiPIMS is lower as well as its duty cycle (f=100 Hz, duty 1%). Different metallic targets (Ti, Cu) and different cathode voltages were applied to get required stoichiometry of Ti-Cu thin films. The plasma parameters of the interspace between magnetrons in the substrate position were investigated by time-resolved optical emission spectroscopy, Langmuir probe technique, and measurement of ion fluxes to the substrate. It is shown that plasma density as well as ion flux is higher about two orders of magnitude in dual-HiPIMS system. This fact is partially caused by low diffusion of ionized sputtered particles (Ti + ,Cu + ) which creates a preionized medium.

Study of uranium dioxyde sputtering induced by multicharged heavy ions at low and very low kinetic energy: projectile charge effect

International Nuclear Information System (INIS)

Haranger, F.

2003-12-01

Ion beam irradiation of a solid can lead to the emission of neutral or ionized atoms, molecules or clusters from the surface. This comes as a result of the atomic motion in the vicinity of the surface, induced by the transfer of the projectile energy. Then, the study of the sputtering process appears as a means to get a better understanding of the excited matter state around the projectile trajectory. In the case of slow multicharged ions, a strong electronic excitation can be achieved by the projectile neutralization above the solid surface and / or its deexcitation below the surface. Parallel to this, the slowing down of such ions is essentially related to elastic collision with the target atoms. The study of the effect of the initial charge state of slow multicharged ions, in the sputtering process, has been carried out by measuring the absolute angular distributions of emission of uranium atoms from a uranium dioxide surface. The experiments have been performed in two steps. First, the emitted particles are collected onto a substrate during irradiation. Secondly, the surface of the collectors is analyzed by Rutherford Backscattering Spectrometry (RBS). This method allows the characterization of the emission of neutrals, which are the vast majority of the sputtered particles. The results obtained provide an access to the evolution of the sputtering process as a function of xenon projectile ions charge state. The measurements have been performed over a wide kinetic energy range, from 81 down to 1.5 keV. This allowed a clear separation of the contribution of the kinetic energy and initial projectile charge state to the sputtering phenomenon. (author)

Particle-balance models for pulsed sputtering magnetrons

Science.gov (United States)

Huo, Chunqing; Lundin, D.; Gudmundsson, J. T.; Raadu, M. A.; Bradley, J. W.; Brenning, N.

2017-09-01

The time-dependent plasma discharge ionization region model (IRM) has been under continuous development during the past decade and used in several studies of the ionization region of high-power impulse magnetron sputtering (HiPIMS) discharges. In the present work, a complete description of the most recent version of the IRM is given, which includes improvements, such as allowing for returning of the working gas atoms from the target, a separate treatment of hot secondary electrons, addition of doubly charged metal ions, etc. To show the general applicability of the IRM, two different HiPIMS discharges are investigated. The first set concerns 400 μs long discharge pulses applied to an Al target in an Ar atmosphere at 1.8 Pa. The second set focuses on 100 μs long discharge pulses applied to a Ti target in an Ar atmosphere at 0.54 Pa, and explores the effects of varying the magnetic field strength. The model results show that Al2+ -ions contribute negligibly to the production of secondary electrons, while Ti2+ -ions effectively contribute to the production of secondary electrons. Similarly, the model results show that for an argon discharge with Al target the contribution of Al+-ions to the discharge current at the target surface is over 90% at 800 V. However, at 400 V the Al+-ions and Ar+-ions contribute roughly equally to the discharge current in the initial peak, while in the plateau region Ar+-ions contribute to roughly \\frac{2}{3} of the current. For high currents the discharge with Al target develops almost pure self-sputter recycling, while the discharge with Ti target exhibits close to a 50/50 combination of self-sputter recycling and working gas-recycling. For a Ti target, a self-sputter yield significantly below unity makes working gas-recycling necessary at high currents. For the discharge with Ti target, a decrease in the B-field strength, resulted in a corresponding stepwise increase in the discharge resistivity.

Effect of Carbon Concentration on the Sputtering of Carbon-Rich SiC Bombarded by Helium Ions

Directory of Open Access Journals (Sweden)

Xinghao Liang

2018-02-01

Full Text Available Silicon carbide (SiC is considered as an important material for nuclear engineering due to its excellent properties. Changing the carbon content in SiC can regulate and control its elastic and thermodynamic properties, but a simulation study of the effect of carbon content on the sputtering (caused by the helium ions of SiC is still lacking. In this work, we used the Monte-Carlo and molecular dynamics simulation methods to study the effects of carbon concentration, incidence energy, incident angle, and target temperature on the sputtering yield of SiC. The results show that the incident ions’ energy and angle have a significant effect on sputtering yield of SiC when the carbon concentration in SiC is around 62 at %, while the target temperature has a little effect on the sputtering yield of SiC. Our work might provide theoretical support for the experimental research and engineering application of carbon fiber-reinforced SiC that be used as the plasma-facing material in tokamak fusion reactors.

Introduction to the experimental study of hadronic matter in heavy ion collisions. The Quark Gluon Plasma

International Nuclear Information System (INIS)

Martinez, G.

2006-12-01

In the last 20 years, heavy ion collisions have been an unique way to study the hadronic matter in the laboratory. The phase diagram of hadronic matter remains unknown, although many experimental and theoretical studies have been done in the last decade, aiming at studying its phase transitions. After a general introduction, two phases transition of the hadronic matter, liquid-gas and the transition to the Quark Gluon Plasma, are addressed. A general view about the experimental methods to study these phase transitions is presented in chapter three. The most important results of the heavy ion program in the RHIC collider at BNL (Upton, N.Y., Usa) are presented in chapter four. The last three chapters are devoted to the heavy ion program in the future large hadron collider (LHC) at CERN (Geneva, Switzerland). In particular, the unique LHC experiment specially designed for heavy ion physics, ALICE and its muon spectrometer are presented. (author)

Heavy-Ion-Induced Electronic Desorption of Gas from Metals

CERN Document Server

Molvik, A W; Mahner, E; Kireeff Covo, M; Bellachioma, M C; Bender, M; Bieniosek, F M; Hedlund, E; Krämer, A; Kwan, J; Malyshev, O B; Prost, L; Seidl, P A; Westenskow, G; Westerberg, L

2007-01-01

During heavy-ion operation in several particle accelerators worldwide, dynamic pressure rises of orders of magnitude were triggered by lost beam ions that bombarded the vacuum chamber walls. This ion-induced molecular desorption, observed at CERN, GSI, and BNL, can seriously limit the ion beam lifetime and intensity of the accelerator. From dedicated test stand experiments we have discovered that heavy-ion-induced gas desorption scales with the electronic energy loss (dEe/dx) of the ions slowing down in matter; but it varies only little with the ion impact angle, unlike electronic sputtering.

Measured signatures of low energy, physical sputtering in the line shape of neutral carbon emission

Energy Technology Data Exchange (ETDEWEB)

Brooks, N.H. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States)]. E-mail: brooks@fusion.gat.com; Isler, R.C. [Oak Ridge National Laboratory, Oak Ridge, TN 37831-6169 (United States); Whyte, D.G. [University of Wisconsin, Madison, WI 53706 (United States); Fenstermacher, M.E. [Livermore National Laboratory, Livermore, CA 94550 (United States); Groebner, R.J. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Stangeby, P.C. [University of Toronto Institute for Aerospace Studies, Toronto, M3H 5T6 (Canada); Heidbrink, W.W. [University of California, Irvine, CA 92697 (United States); Jackson, G.L. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); Mahdavi, M.A. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States); West, W.P. [General Atomics, P.O. Box 85608, San Diego, CA 92186-5608 (United States)

2005-03-01

The most important mechanisms for introducing carbon into the DIII-D divertors [J.L. Luxon, Nucl. Fusion 42 (2002) 614] are physical and chemical sputtering. Previous investigations have indicated that operating conditions where one or the other of these is dominant can be distinguished by using CD and C{sub 2} emissions to infer C I influxes from dissociation of hydrocarbons and comparing to measured C I influxes. The present work extends these results through detailed analysis of the C I spectral line shapes. In general, it is found that the profiles are actually asymmetric and have shifted peaks. These features are interpreted as originating from a combination of an anisotropic velocity distribution from physical sputtering (the Thompson model) and an isotropic distribution from molecular dissociation. The present study utilizes pure helium plasmas to benchmark C I spectral profiles arising from physical sputtering alone.

High-power sputtering employed for film deposition

International Nuclear Information System (INIS)

Shapovalov, V I

2017-01-01

The features of high-power magnetron sputtering employed for the films’ deposition are reviewed. The main physical phenomena accompanying high-power sputtering including ion-electron emission, gas rarefaction, ionization of sputtered atoms, self-sputtering, ion sound waves and the impact of the target heating are described. (paper)

Enhanced saturation of sputtered amorphous SiN film frameworks using He- and Ne-Penning effects

Science.gov (United States)

Sugimoto, Iwao; Nakano, Satoko; Kuwano, Hiroki

1994-06-01

Optical emission spectroscopy reveals that helium and neon gases enhance the nitridation reactivity of the nitrogen plasma by Penning effects during magnetron sputtering of the silicon target. These excited nitrogen plasmas promote the saturation of frameworks of the resultant silicon nitride films. X-ray photoelectron spectroscopy, electron spin resonance, and x-ray diffraction analyses provide insight into the structure of these films, and thermal desorption mass spectroscopy reveals the behavior of volatile species in these films.

Magnetron reactively sputtered Ti-DLC coatings on HNBR rubber : The influence of substrate bias

NARCIS (Netherlands)

Bui, X.L.; Pei, Y.T.; Hosson, J.Th.M. De

2008-01-01

In this study, Ti-containing diamond-like carbon (Ti-DLC) coatings have been deposited on HNBR (hydrogenated nitrile butadiene) rubber and also on Si wafer as reference via unbalanced magnetroli reactive sputtering from a Ti target in C2H2/Ar plasma. The deposition rates of coatings on rubber and Si

Hollow cathode discharges with gas flow: numerical modelling for the effect on the sputtered atoms and the deposition flux

International Nuclear Information System (INIS)

Bogaerts, Annemie; Okhrimovskyy, Andriy; Baguer, Neyda; Gijbels, Renaat

2005-01-01

A model is developed for a cylindrical hollow cathode discharge (HCD), with an axial gas flow (entering through a hole in the cathode bottom). The model combines a commercial computational fluid dynamics program 'FLUENT' to compute the gas flow, with home-developed Monte Carlo and fluid models for the plasma behaviour. In this paper, we focus on the behaviour of the sputtered atoms, and we investigate how the gas flow affects the sputtered atom density profiles and the fluxes, which is important for sputter deposition. The sputtered atom density profiles are not much affected by the gas flow. The flux, on the other hand, is found to be significantly enhanced by the gas flow, but in the present set-up it is far from uniform in the radial direction at the open end of the HCD, where a substrate for deposition could be located

Hybrid Simulation of the Interaction of Europa's Atmosphere with the Jovian Plasma: Multiprocessor Simulations

Science.gov (United States)

Dols, V. J.; Delamere, P. A.; Bagenal, F.; Cassidy, T. A.; Crary, F. J.

2014-12-01

We model the interaction of Europa's tenuous atmosphere with the plasma of Jupiter's torus with an improved version of our hybrid plasma code. In a hybrid plasma code, the ions are treated as kinetic Macro-particles moving under the Lorentz force and the electrons as a fluid leading to a generalized formulation of Ohm's law. In this version, the spatial simulation domain is decomposed in 2 directions and is non-uniform in the plasma convection direction. The code is run on a multi-processor supercomputer that offers 16416 cores and 2GB Ram per core. This new version allows us to tap into the large memory of the supercomputer and simulate the full interaction volume (Reuropa=1561km) with a high spatial resolution (50km). Compared to Io, Europa's atmosphere is about 100 times more tenuous, the ambient magnetic field is weaker and the density of incident plasma is lower. Consequently, the electrodynamic interaction is also weaker and substantial fluxes of thermal torus ions might reach and sputter the icy surface. Molecular O2 is the dominant atmospheric product of this surface sputtering. Observations of oxygen UV emissions (specifically the ratio of OI 1356A / 1304A emissions) are roughly consistent with an atmosphere that is composed predominantely of O2 with a small amount of atomic O. Galileo observations along flybys close to Europa have revealed the existence of induced currents in a conducting ocean under the icy crust. They also showed that, from flyby to flyby, the plasma interaction is very variable. Asymmetries of the plasma density and temperature in the wake of Europa were also observed and still elude a clear explanation. Galileo mag data also detected ion cyclotron waves, which is an indication of heavy ion pickup close to the moon. We prescribe an O2 atmosphere with a vertical density column consistent with UV observations and model the plasma properties along several Galileo flybys of the moon. We compare our results with the magnetometer

Laser fluorescence spectroscopy of sputtered uranium atoms

International Nuclear Information System (INIS)

Wright, R.B.; Pellin, M.J.; Gruen, D.M.; Young, C.E.

1979-01-01

Laser induced fluorescence (LIF) spectroscopy was used to study the sputtering of 99.8% 238 U metal foil when bombarded by normally incident 500 to 3000 eV Ne + , Ar + , Kr + , and O 2 + . A three-level atom model of the LIF processes is developed to interpret the observed fluorescent emission from the sputtered species. The model shows that close attention must be paid to the conditions under which the experiment is carried out as well as to the details of the collision cascade theory of sputtering. Rigorous analysis shows that when properly applied, LIF can be used to investigate the predictions of sputtering theory as regards energy distributions of sputtered particles and for the determination of sputtering yields. The possibility that thermal emission may occur during sputtering can also be tested using the proposed model. It is shown that the velocity distribution (either the number density or flux density distribution, depending upon the experimental conditions) of the sputtered particles can be determined using the LIF technique and that this information can be used to obtain a description of the basic sputtering mechanisms. These matters are discussed using the U-atom fluorescence measurements as a basis. The relative sputtering yields for various incident ions on uranium were also measured for the first time using the LIF technique. A surprisingly high fraction of the sputtered uranium atoms were found to occupy the low lying metastable energy levels of U(I). The population of the sputtered metastable atoms were found approximately to obey a Boltzman distribution with an effective temperature of 920 +- 100 0 K. 41 references

Thin films preparation of the Ti-Al-O system by rf-sputtering;Preparacion de peliculas delgadas del sistema Ti-Al-O mediante rf-sputtering

Energy Technology Data Exchange (ETDEWEB)

Montes de Oca, J. A.; Ceballos A, J.; Galaviz P, J. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Altamira, Km 14.5 Carretera Tampico-Puerto Industrial Altamira, 89600 Altamira, Tamaulipas (Mexico); Manaud, J. P.; Lahaye, M. [Centre National de la Recherche Scientifique, Institut de Chimie de la Matiere Condensee, Universite Bordeaux I, 87, Av. du Dr. Schweitzer, F-33608 Pessac-Cedex (France); Munoz S, J., E-mail: jmontedeocacv@ipn.m [IPN, Centro de Investigacion y de Estudios Avanzados, Unidad Queretaro, Libramiento Norponiente No. 2000, Fracc. Real de Juriquilla, 76230 Santiago de Queretaro, Qro. (Mexico)

2010-07-01

In the present work Ti-Al-O thin films were synthesized by rf-sputtering technique on glass and silicon (Si) substrates using Ti Al and Ti{sub 3}Al targets in a sputtering chamber with an Ar-O{sub 2} atmosphere. Ti-Al-O thin films were obtained varying experimental parameters such as oxygen percent fed to the reaction chamber, plasma power density and substrate temperature. The films deposited on glass substrates were used to evaluate their optical properties, while those deposited on Si substrates were used to evaluate mechanical and morphological properties. The crystalline structure, morphology, chemical composition and optical properties of the films were evaluated by X-ray diffraction, high-resolution scanning electron microscopy, Auger electron microscopy and visible UV spectroscopy. Films thicknesses were measured using a profiler. The roughness and mechanical properties such as hardness and Young modulus were analyzed by atomic force microscopy and nano indentation technique, respectively. (Author)

Controlled elaboration of large-area plasmonic substrates by plasma process

International Nuclear Information System (INIS)

Pugliara, A; Despax, B; Makasheva, K; Bonafos, C; Carles, R

2015-01-01

Elaboration in a controlled way of large-area and efficient plasmonic substrates is achieved by combining sputtering of silver nanoparticles (AgNPs) and plasma polymerization of the embedding dielectric matrix in an axially asymmetric, capacitively coupled RF discharge maintained at low gas pressure. The plasma parameters and deposition conditions were optimized according to the optical response of these substrates. Structural and optical characterizations of the samples confirm the process efficiency. The obtained results indicate that to deposit a single layer of large and closely situated AgNPs, a high injected power and short sputtering times must be privileged. The plasma-elaborated plasmonic substrates appear to be very sensitive to any stimuli that affect their plasmonic response. (paper)

Heavy ion beam probe (HIBP) diagnostics as a tool for investigations into the plasma turbulence and the local electric field of dense plasma

Energy Technology Data Exchange (ETDEWEB)

Krupnik, L.I.; Chmyga, A.A.; Komarov, A.D.; Kozachok, A.S.; Zhezhera, A.I. [Institute of Plasma Physics, NSC KIPT, 310108 Kharkov (Ukraine); Melnikov, A.V.; Eliseev, L.G.; Lysenko, S.E.; Mavrin, V.A.; Perfilov, S.V. [Institute of Nuclear Fusion, RRC ' Kurchatov Institute' , Moscow (Russian Federation); Hidalgo, C.; Ascasibar, E.; Estrada, T.; Liniers, M.; Ochando, M.A.; Pablos, J.L. de; Pedrosa, M.A.; Tabares, F. [Laboratorio Nacional de Fusion por Confinamiento Magnetico, Asociacion EURATOM-CIEMAT, 28040-Madrid (Spain)

2011-07-01

One of essential achievements of the Heavy Ion Beam Probe (HIBP) diagnostics is the possibility to use it for investigation of plasma confinement by measuring the fluctuations of electric field and plasma density; the method is based on the important role of the plasma electric fields. Both edge and core transport barriers are related to a large increase in the E*B sheared flows in a fusion device. In the TJ-II stellarator the HIBP diagnostics has recently been upgraded for two-point measurements with a good spatial (1 cm) and temporal (10 {mu}s) resolution of the plasma electric potential and density, as well as their fluctuations and poloidal component of electric field, E{sub p} equals ({phi}1 - {phi}2)/{Delta}r [V/cm]; these data give chance to extract the radial turbulent particle flux: {Gamma}(r) equals {Gamma}(Epol*Btor) equals {Gamma}(E*B). (authors)

Nucleation of ultrathin silver layer by magnetron sputtering in Ar/N2 plasma

Czech Academy of Sciences Publication Activity Database

Bulíř, Jiří; Novotný, Michal; Lančok, Ján; Fekete, Ladislav; Drahokoupil, Jan; Musil, Jindřich

2013-01-01

Roč. 228, č. 1 (2013), S86-S90 ISSN 0257-8972 R&D Projects: GA ČR(CZ) GAP108/11/1298; GA ČR GP202/09/P324 Institutional support: RVO:68378271 Keywords : ultrathin silver * magnetron sputtering * spectral ellipsometry * in-situ monitoring Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.199, year: 2013

Optical emission spectroscopy during fabrication of indium-tin-oxynitride films by RF-sputtering

International Nuclear Information System (INIS)

Koufaki, M.; Sifakis, M.; Iliopoulos, E.; Pelekanos, N.; Modreanu, M.; Cimalla, V.; Ecke, G.; Aperathitis, E.

2006-01-01

Indium-tin-oxide (ITO) and indium-tin-oxynitride (ITON) films have been deposited on glass by rf-sputtering from an ITO target, using Ar plasma and N 2 plasma, respectively, and different rf-power. Optical emission spectroscopy (OES) was employed to identify the species present in the plasma and to correlate them with the properties of the ITO and ITON thin films. Emission lines of ionic In could only be detected in N 2 plasma, whereas in the Ar plasma additional lines corresponding to atomic In and InO, were detected. The deposition rate of thin films was correlated with the In species, rather than the nitrogen species, emission intensity in the plasma. The higher resistivity and lower carrier concentration of the ITON films, as compared to the respective properties of the ITO films, were attributed to the incorporation of nitrogen, instead of oxygen, in the ITON structure

Interaction of a vacuum arc plasma beam with an obstacle positioned normal to the plasma flow

International Nuclear Information System (INIS)

Zarchin, O; Zhitomirsky, V N; Goldsmith, S; Boxman, R L

2003-01-01

The effect of an obstacle positioned normal to a plasma jet produced by a vacuum arc plasma source on the radial distribution of ion flux in the vicinity of the obstacle was studied. This study was motivated by interest in the mutual influence of tightly packed substrates on coatings in industrial vacuum arc deposition systems. The experimental system consisted of a vacuum arc plasma source, a straight plasma duct, and a multi-probe consisting of a removable disc obstacle and a set of ring probes for measuring the radial ion flux. A dc arc discharge was ignited in vacuum between a truncated cone-shaped Cu cathode and an annular anode. The plasma jet produced by cathode spots passed through the anode aperture into the straight plasma duct. An axial magnetic field guided the plasma jet in the duct. The multi-probe consisted of a removable disc obstacle and a set of five ring probes for measuring the radial plasma flux as a function of distance from the disc obstacle. The rings and the disc probes were coaxially arranged on the multi-probe assembly and positioned so that plasma from the source passed through the ring probes and then encountered the disc. The influence of the obstacle was determined by measuring the ring ion currents, both in the presence of the obstacle, and when the disc obstacle was removed. The difference between the measured ion currents with and without the obstacle was interpreted to be the contribution of reflected or sputtered particles from the obstacle to the radial ion flux. The ring probes were biased by -60 V with respect to the grounded anode, to collect the saturated ion current. The multi-probe was connected to a movable stem, and positioned at different distances from the plasma source. A plasma density of ∼6 x 10 17 m -3 was estimated in this study based on the ion current to the obstacle. The radial ion flux collected by the ring probes increased by 20-25% due to the presence of the obstacle. As the calculated mean free path for

Non-uniform Erosion and Surface Evolution of Plasma-Facing Materials for Electric Propulsion

Science.gov (United States)

Matthes, Christopher Stanley Rutter

A study regarding the surface evolution of plasma-facing materials is presented. Experimental efforts were performed in the UCLA Pi Facility, designed to explore the physics of plasma-surface interactions. The influence of micro-architectured surfaces on the effects of plasma sputtering is compared with the response of planar samples. Ballistic deposition of sputtered atoms as a result of geometric re-trapping is observed. This provides a self-healing mechanism of micro-architectured surfaces during plasma exposure. This result is quantified using a QCM to demonstrate the evolution of surface features and the corresponding influence on the instantaneous sputtering yield. The sputtering yield of textured molybdenum samples exposed to 300 eV Ar plasma is found to be roughly 1 of the 2 corresponding value of flat samples, and increases with ion fluence. Mo samples exhibited a sputtering yield initially as low as 0.22+/-8%, converging to 0.4+/-8% at high fluence. Although the yield is dependent on the initial surface structure, it is shown to be transient, reaching a steady-state value that is independent of initial surface conditions. A continuum model of surface evolution resulting from sputtering, deposition and surface diffusion is also derived to resemble the damped Kuramoto-Sivashinsky (KS) equation of non-linear dynamics. Linear stability analysis of the evolution equation provides an estimate of the selected wavelength, and its dependence on the ion energy and angle of incidence. The analytical results are confirmed by numerical simulations of the equation with a Fast Fourier Transform method. It is shown that for an initially flat surface, small perturbations lead to the evolution of a selected surface pattern that has nano- scale wavelength. When the surface is initially patterned by other means, the final resulting pattern is a competition between the "templated" pattern and the "self-organized" structure. Potential future routes of research are also

Computer simulation of sputtering of graphite target in magnetron sputtering device with two zones of erosion

Directory of Open Access Journals (Sweden)

Bogdanov R.V.

2015-03-01

Full Text Available A computer simulation program for discharge in a magnetron sputtering device with two erosion zones was developed. Basic laws of the graphite target sputtering process and transport of sputtered material to the substrate were taken into account in the Monte Carlo code. The results of computer simulation for radial distributions of density and energy flux of carbon atoms on the substrate (at different values of discharge current and pressure of the working gas confirmed the possibility of obtaining qualitative homogeneous films using this magnetron sputtering device. Also the discharge modes were determined for this magnetron sputtering device, in which it was possible to obtain such energy and density of carbon atoms fluxes, which were suitable for deposition of carbon films containing carbon nanotubes and other nanoparticles.

Sputtering of water ice

DEFF Research Database (Denmark)

Baragiola, R.A.; Vidal, R.A.; Svendsen, W.

2003-01-01

We present results of a range of experiments of sputtering of water ice together with a guide to the literature. We studied how sputtering depends on the projectile energy and fluence, ice growth temperature, irradiation temperature and external electric fields. We observed luminescence from...

Development of a 1-m plasma source for heavy ion beam charge neutralization

Science.gov (United States)

Efthimion, Philip C.; Gilson, Erik P.; Grisham, Larry; Davidson, Ronald C.; Yu, Simon; Waldron, William; Grant Logan, B.

2005-05-01

Highly ionized plasmas are being employed as a medium for charge neutralizing heavy ion beams in order to focus to a small spot size. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length ˜0.1-1 m would be suitable for achieving a high level of charge neutralization. A radio frequency (RF) source was constructed at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization. Pulsing the source enabled operation at pressures ˜10 -6 Torr with plasma densities of 10 11 cm -3. Near 100% ionization was achieved. The plasma was 10 cm in length, but future experiments require a source 1 m long. The RF source does not easily scale to the length. Consequently, large-volume plasma sources based upon ferroelectric ceramics are being considered. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source will utilize the ferroelectric ceramic BaTiO 3 to form metal plasma. A 1 m long section of the drift tube inner surface of NTX will be covered with ceramic. A high voltage (˜1-5 kV) is applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. Plasma densities of 10 12 cm -3 and neutral pressures ˜10 -6 Torr are expected. A test stand to produce 20 cm long plasma is being constructed and will be tested before a 1 m long source is developed.

Development of a 1-m plasma source for heavy ion beam charge neutralization

International Nuclear Information System (INIS)

Efthimion, Philip C.; Gilson, Erik P.; Grisham, Larry; Davidson, Ronald C.; Yu, Simon; Waldron, William; Grant Logan, B.

2005-01-01

Highly ionized plasmas are being employed as a medium for charge neutralizing heavy ion beams in order to focus to a small spot size. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length ∼0.1-1 m would be suitable for achieving a high level of charge neutralization. A radio frequency (RF) source was constructed at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization. Pulsing the source enabled operation at pressures ∼10 -6 Torr with plasma densities of 10 11 cm -3 . Near 100% ionization was achieved. The plasma was 10 cm in length, but future experiments require a source 1 m long. The RF source does not easily scale to the length. Consequently, large-volume plasma sources based upon ferroelectric ceramics are being considered. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source will utilize the ferroelectric ceramic BaTiO 3 to form metal plasma. A 1 m long section of the drift tube inner surface of NTX will be covered with ceramic. A high voltage (∼1-5 kV) is applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. Plasma densities of 10 12 cm -3 and neutral pressures ∼10 -6 Torr are expected. A test stand to produce 20 cm long plasma is being constructed and will be tested before a 1 m long source is developed

Simulation experiments and solar wind sputtering

International Nuclear Information System (INIS)

Griffith, J.E.; Papanastassiou, D.A.; Russell, W.A.; Tombrello, T.A.; Weller, R.A.

1978-01-01

In order to isolate the role played by solar wind sputtering from other lunar surface phenomena a number of simulation experiments were performed, including isotope abundance measurements of Ca sputtered from terrestrial fluorite and plagioclase by 50-keV and 130-keV 14 N beams, measurement of the energy distribution of U atoms sputtered with 80-keV 40 Ar, and measurement of the fraction of sputtered U atoms which stick on the surfaces used to collect these atoms. 10 references

Plasma and process characterization of high power magnetron physical vapor deposition with integrated plasma equipment--feature profile model

International Nuclear Information System (INIS)

Zhang Da; Stout, Phillip J.; Ventzek, Peter L.G.

2003-01-01

High power magnetron physical vapor deposition (HPM-PVD) has recently emerged for metal deposition into deep submicron features in state of the art integrated circuit fabrication. However, the plasma characteristics and process mechanism are not well known. An integrated plasma equipment-feature profile modeling infrastructure has therefore been developed for HPM-PVD deposition, and it has been applied to simulating copper seed deposition with an Ar background gas for damascene metalization. The equipment scale model is based on the hybrid plasma equipment model [M. Grapperhaus et al., J. Appl. Phys. 83, 35 (1998); J. Lu and M. J. Kushner, ibid., 89, 878 (2001)], which couples a three-dimensional Monte Carlo sputtering module within a two-dimensional fluid model. The plasma kinetics of thermalized, athermal, and ionized metals and the contributions of these species in feature deposition are resolved. A Monte Carlo technique is used to derive the angular distribution of athermal metals. Simulations show that in typical HPM-PVD processing, Ar + is the dominant ionized species driving sputtering. Athermal metal neutrals are the dominant deposition precursors due to the operation at high target power and low pressure. The angular distribution of athermals is off axis and more focused than thermal neutrals. The athermal characteristics favor sufficient and uniform deposition on the sidewall of the feature, which is the critical area in small feature filling. In addition, athermals lead to a thick bottom coverage. An appreciable fraction (∼10%) of the metals incident to the wafer are ionized. The ionized metals also contribute to bottom deposition in the absence of sputtering. We have studied the impact of process and equipment parameters on HPM-PVD. Simulations show that target power impacts both plasma ionization and target sputtering. The Ar + ion density increases nearly linearly with target power, different from the behavior of typical ionized PVD processing. The

Heavy impurity confinement in hybrid operation scenario plasmas with a rotating 1/1 continuous mode

Science.gov (United States)

Raghunathan, M.; Graves, J. P.; Nicolas, T.; Cooper, W. A.; Garbet, X.; Pfefferlé, D.

2017-12-01

In future tokamaks like ITER with tungsten walls, it is imperative to control tungsten accumulation in the core of operational plasmas, especially since tungsten accumulation can lead to radiative collapse and disruption. We investigate the behavior of tungsten trace impurities in a JET-like hybrid scenario with both axisymmetric and saturated 1/1 ideal helical core in the presence of strong plasma rotation. For this purpose, we obtain the equilibria from VMEC and use VENUS-LEVIS, a guiding-center orbit-following code, to follow heavy impurity particles. In this work, VENUS-LEVIS has been modified to account for strong plasma flows with associated neoclassical effects arising from such flows. We find that the combination of helical core and plasma rotation augments the standard neoclassical inward pinch compared to axisymmetry, and leads to a strong inward pinch of impurities towards the magnetic axis despite the strong outward diffusion provided by the centrifugal force, as frequently observed in experiments.

Merging and Splitting of Plasma Spheroids in a Dusty Plasma

Science.gov (United States)

Mikikian, Maxime; Tawidian, Hagop; Lecas, Thomas

2012-12-01

Dust particle growth in a plasma is a strongly disturbing phenomenon for the plasma equilibrium. It can induce many different types of low-frequency instabilities that can be experimentally observed, especially using high-speed imaging. A spectacular case has been observed in a krypton plasma where a huge density of dust particles is grown by material sputtering. The instability consists of well-defined regions of enhanced optical emission that emerge from the electrode vicinity and propagate towards the discharge center. These plasma spheroids have complex motions resulting from their mutual interaction that can also lead to the merging of two plasma spheroids into a single one. The reverse situation is also observed with the splitting of a plasma spheroid into two parts. These results are presented for the first time and reveal new behaviors in dusty plasmas.

Improvement of confinement characteristics of tokamak plasma by controlling plasma-wall interactions

International Nuclear Information System (INIS)

Sengoku, Seio

1985-08-01

Relation between plasma-wall interactions and confinement characteristics of a tokamak plasma with respect to both impurity and fuel particle controls is discussed. Following results are obtained from impurity control studies: (1) Ion sputtering is the dominant mechanism of impurity release in a steady state tokamak discharge. (2) By applying carbon coating on entire first wall of DIVA tokamak, dominant radiative region is concentrated more in boundary plasma resulting a hot peripheral plasma with cold boundary plasma. (3) A physical model of divertor functions about impurity control is empilically obtained. By a computer simulation based on above model with respect to divertor functions for JT-60 tokamak, it is found that the allowable electron temperature of the divertor plasma is not restricted by a condition that the impurity release due to ion sputtering does not increase continuously. (4) Dense and cold divertor plasma accompanied with strong remote radiative cooling was diagnosed along the magnetic field line in the simple poloidal divertor of DOUBLET III tokamak. Strong particle recycling region is found to be localized near the divertor plate. by and from particle control studies: (1) The INTOR scaling on energy confinement time is applicable to high density region when a core plasma is fueled directly by solid deuterium pellet injection in DOUBLET III tokamak. (2) As remarkably demonstrated by direct fueling with pellet injection, energy confinement characteristics can be improved at high density range by decreasing particle deposition at peripheral plasma in order to reduce plasma-wall interaction. (3) If the particle deposition at boundary layer is necessarily reduced, the electron temperature at the boundary or divertor region increases due to decrease of the particle recycling and the electron density there. (J.P.N.)

High-surface-quality nanocrystalline InN layers deposited on GaN templates by RF sputtering

Energy Technology Data Exchange (ETDEWEB)

Valdueza-Felip, Sirona; Naranjo, Fernando B.; Gonzalez-Herraez, Miguel [Grupo de Ingenieria Fotonica, Departamento de Electronica, Escuela Politecnica Superior, Universidad de Alcala, Campus Universitario, 28871 Alcala de Henares, Madrid (Spain); Lahourcade, Lise; Monroy, Eva [Equipe mixte CEA-CNRS-UJF, Nanophysique et Semiconducteurs, INAC/SP2M/PSC, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Fernandez, Susana [Departamento de Energias Renovables, Energia Solar Fotovoltaica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Avda. Complutense 22, 28040 Madrid (Spain)

2011-01-15

We report a detailed study of the effect of deposition parameters on optical, structural, and morphological properties of InN films grown by reactive radio-frequency (RF) sputtering on GaN-on-sapphire templates in a pure nitrogen atmosphere. Deposition parameters under study are substrate temperature, RF power, and sputtering pressure. Wurtzite crystallographic structure with c-axis preferred growth orientation is confirmed by X-ray diffraction measurements. For the optimized deposition conditions, namely at a substrate temperature of 450 C and RF power of 30 W, InN films present a root-mean-square surface roughness as low as {proportional_to}0.4 nm, comparable to the underlying substrate. The apparent optical bandgap is estimated at 720 nm (1.7 eV) in all cases. However, the InN absorption band tail is strongly influenced by the sputtering pressure due to a change in the species of the plasma. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Investigation of plasma dynamics during the growth of amorphous titanium dioxide thin films

Science.gov (United States)

Kim, Jin-Soo; Jee, Hyeok; Yu, Young-Hun; Seo, Hye-Won

2018-06-01

We have grown amorphous titanium dioxide thin films by reactive DC sputtering method using a different argon/oxygen partial pressure at a room temperature. The plasma dynamics of the process, reactive and sputtered gas particles was investigated via optical emission spectroscopy. We then studied the correlations between the plasma states and the structural/optical properties of the films. The growth rate and morphology of the titanium dioxide thin films turned out to be contingent with the population and the energy profile of Ar, O, and TiO plasma. In particular, the films grown under energetic TiO plasma have shown a direct band-to-band transition with an optical energy band gap up to ∼4.2 eV.

Implantation, recoil implantation, and sputtering

International Nuclear Information System (INIS)

Kelly, R.

1984-01-01

The implantation and sputtering mechanisms which are relevant to ion bombardment of surfaces are described. These are: collision, thermal, electronic and photon-induced sputtering. 135 refs.; 36 figs.; 9 tabs

Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films

Directory of Open Access Journals (Sweden)

Partha Saikia

2016-04-01

Full Text Available We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te, electron density (ne, ion density (ni, degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.

Time-Domain Modeling of RF Antennas and Plasma-Surface Interactions

Directory of Open Access Journals (Sweden)

Jenkins Thomas G.

2017-01-01

Full Text Available Recent advances in finite-difference time-domain (FDTD modeling techniques allow plasma-surface interactions such as sheath formation and sputtering to be modeled concurrently with the physics of antenna near- and far-field behavior and ICRF power flow. Although typical sheath length scales (micrometers are much smaller than the wavelengths of fast (tens of cm and slow (millimeter waves excited by the antenna, sheath behavior near plasma-facing antenna components can be represented by a sub-grid kinetic sheath boundary condition, from which RF-rectified sheath potential variation over the surface is computed as a function of current flow and local plasma parameters near the wall. These local time-varying sheath potentials can then be used, in tandem with particle-in-cell (PIC models of the edge plasma, to study sputtering effects. Particle strike energies at the wall can be computed more accurately, consistent with their passage through the known potential of the sheath, such that correspondingly increased accuracy of sputtering yields and heat/particle fluxes to antenna surfaces is obtained. The new simulation capabilities enable time-domain modeling of plasma-surface interactions and ICRF physics in realistic experimental configurations at unprecedented spatial resolution. We will present results/animations from high-performance (10k-100k core FDTD/PIC simulations of Alcator C-Mod antenna operation.

Low-Damage Sputter Deposition on Graphene

Science.gov (United States)

Chen, Ching-Tzu; Casu, Emanuele; Gajek, Marcin; Raoux, Simone

2013-03-01

Despite its versatility and prevalence in the microelectronics industry, sputter deposition has seen very limited applications for graphene-based electronics. We have systematically investigated the sputtering induced graphene defects and identified the reflected high-energy neutrals of the sputtering gas as the primary cause of damage. In this talk, we introduce a novel sputtering technique that is shown to dramatically reduce bombardment of the fast neutrals and improve the structural integrity of the underlying graphene layer. We also demonstrate that sputter deposition and in-situ oxidation of 1 nm Al film at elevated temperatures yields homogeneous, fully covered oxide films with r.m.s. roughness much less than 1 monolayer, which shows the potential of using such technique for gate oxides, tunnel barriers, and multilayer fabrication in a wide range of graphene devices.

Au-nanoparticles grafted on plasma treated PE

International Nuclear Information System (INIS)

Svorcik, V.; Chaloupka, A.; Rezanka, P.; Slepicka, P.; Kolska, Z.; Kasalkova, N.; Hubacek, T.; Siegel, J.

2010-01-01

Polyethylene (PE) surface was treated with Ar plasma. Activated surface was grafted from methanol solution of 1,2-ethanedithiol. Then the sample was immersed into freshly prepared colloid solution of Au-nanoparticles. Finally Au layer was sputtered on the samples. Properties of the modified PE were studied using various methods: AFM, EPR, RBS and nanoindentation. It was shown that the plasma treatment results in degradation of polymer chain (AFM) and creation of free radicals by EPR. After grafting with dithiol, the concentration of free radicals declines. The presence of Au and S in the surface layer after the coating with Au-nanoparticles was proved by RBS. Plasma treatment changes PE surface morphology and increases surface roughness, too. Another significant change in surface morphology and roughness was observed after deposition of Au-nanoparticles. Nanoindentation measurements show that the grafting with Au-nanoparticles increases adhesion of subsequently sputtered Au layer.

On the topography of sputtered or chemically etched crystals: surface energies minimised

International Nuclear Information System (INIS)

Chadderton, L.T.; Cope, J.O.

1984-01-01

The sputtering of single or polycrystalline metal surfaces by heavy ions gives rise to the characteristic topographical features of etch pits, ripples, and cones (pyramids). For cones and pyramids, in particular, no completely satisfactory explanation exists as to the origin of the basic geometry. Scanning electron micrographs are shown. It is proposed that for topographical features of both chemical etch and ion beam origin on single crystal surfaces, the presence of facets on cones and pyramids in particular, is due to the minimization of surface energy. (U.K.)

Influence of reactive oxygen species during deposition of iron oxide films by high power impulse magnetron sputtering

Czech Academy of Sciences Publication Activity Database

Straňák, V.; Hubička, Zdeněk; Čada, Martin; Bogdanowicz, R.; Wulff, H.; Helm, C.A.; Hippler, R.

2018-01-01

Roč. 51, č. 9 (2018), s. 1-12, č. článku 095205. ISSN 0022-3727 R&D Projects: GA ČR GA17-08389S Institutional support: RVO:68378271 Keywords : high power impulse magnetron sputtering (HiPIMS) * iron oxide thin films * wüstite * magnetite * maghemite * hematite Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics ) Impact factor: 2.588, year: 2016

Studies on ion scattering and sputtering processes relevant to ion beam sputter deposition of multicomponent thin films

International Nuclear Information System (INIS)

Auciello, O.; Ameen, M.S.; Kingon, A.I.

1989-01-01

Results from computer simulation and experiments on ion scattering and sputtering processes in ion beam sputter deposition of high Tc superconducting and ferroelectric thin films are presented. It is demonstrated that scattering of neutralized ions from the targets can result in undesirable erosion of, and inert gas incorporation in, the growing films, depending on the ion/target atom ass ratio and ion beam angle of incidence/target/substrate geometry. The studies indicate that sputtering Kr + or Xe + ions is preferable to the most commonly used Ar + ions, since the undesirable phenomena mentioned above are minimized for the first two ions. These results are used to determine optimum sputter deposition geometry and ion beam parameters for growing multicomponent oxide thin films by ion beam sputter-deposition. 10 refs., 5 figs

2D edge plasma modeling extended up to the main chamber

Energy Technology Data Exchange (ETDEWEB)

Dekeyser, W., E-mail: wouter.dekeyser@mech.kuleuven.be [Department of Mechanical Engineering, Katholieke Universiteit Leuven, Celestijnenlaan 300A, 3001 Leuven (Belgium); Baelmans, M. [Department of Mechanical Engineering, Katholieke Universiteit Leuven, Celestijnenlaan 300A, 3001 Leuven (Belgium); Reiter, D.; Boerner, P.; Kotov, V. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, EURATOM-Association, Trilateral Euregio Cluster, D-52425 Juelich (Germany)

2011-08-01

Far SOL plasma flow, and hence main chamber recycling and plasma surface interaction, are today still only very poorly described by current 2D fluid edge codes, such as B2, UEDGE or EDGE2D, due to a common technical limitation. We have extended the B2 plasma fluid solver in the current ITER version of B2-EIRENE (SOLPS4.3) to allow plasma solutions to be obtained up to the 'real vessel wall', at least on the basis of ad hoc far SOL transport models. We apply here the kinetic Monte Carlo Code EIRENE on such plasma solutions to study effects of this model refinement on main chamber fluxes and sputtering, for an ITER configuration. We show that main chamber sputtering may be significantly modified both due to thermalization of CX neutrals in the far SOL and poloidally highly asymmetric plasma wall contact, as compared to hitherto applied teleportation of particle fluxes across this domain.

Relationship between plasma parameters and film microstructure in radio frequency magnetron sputter deposition of barium strontium titanate

Science.gov (United States)

Panda, B.; Dhar, A.; Nigam, G. D.; Bhattacharya, D.; Ray, S. K.

1998-01-01

Radio frequency magnetron sputtered Ba0.8Sr0.2TiO3 thin films have been deposited on silicon and Si/SiO2/SiN/Pt substrates. The analysis of plasma discharge has been carried out using the Langmuir probe technique. Both the pressure and power have been found to influence the ion density and self-bias of the target. Introduction of oxygen into the discharge effectively decreases the ion density. The structural and electrical properties have been investigated using x-ray diffraction, atomic force microscopy of deposited films and capacitance-voltage, conductance-voltage, and current density-electric field characteristics of fabricated capacitors. The growth and orientation of the films have been found to depend upon the type of substrates and deposition temperatures. The texture in the film is promoted at a pressure 0.25 Torr with a moderately high value of ion density and low ion bombardment energy. Films deposited on Si/SiO2/SiN/Pt substrate have shown higher dielectric constant (191) and lower leakage current density (2.8×10-6 A/cm2 at 100 kV/cm) compared to that on silicon.

Report of the study meeting on the interaction between plasma and the first wall of a fusion reactor

International Nuclear Information System (INIS)

Miyahara, Akira; Akaishi, Kenya; Kawamura, Takaichi; Kabetani, Zenzaburo; Sagara, Akio.

1978-12-01

The study meeting on the interaction between plasma and the first wall of a fusion reactor was held from July 24 to July 27, 1978. At this meeting, discussions were made on the interaction between plasma and wall and the effect of impurities. Reports on the ISS observation concerning the Mo surface as a limiter, on the measurement of sputter rate by a microbalance, on the surface roughness of the materials for the first wall at the atomic order, on the selective sputtering of binary alloys, and on the physical and chemical sputtering on the material surface of C and SiC were also presented. The research projects of the Institute of Plasma Physics and Hokkaido University were introduced. Collaboration of two groups was considered. (Kato, T.)

Deposition of lead-silicate glassy thin coatings by RF magnetron sputtering: Correlation between deposition parameters and electrical and structural properties

International Nuclear Information System (INIS)

Rigato, V.; Maggioni, G.; Boscarino, D.; Della Mea, G.; Univ. di Trento, Mesiano

1996-01-01

Lead-silicate glassy thin films produced by means of Reactive Radio Frequency Magnetron Sputtering have found recent application in the development of MicroStrip Gas Chambers radiation detectors. Here, thin films (100--400 nm) of lead silicate glass have been deposited by RF magnetron sputtering in Ar plasma at different discharge conditions. The interaction of the sputtered species with the gas atoms during the transport process through the discharge region and the kinetics of growth of the films have been investigated as a function of the target composition and of the substrate temperature. This study demonstrates the possibility of controlling the surface electrical resistance of the films in a wide range of values ranging from 10 12 to 10 17 Ω/□ during the film growth

Consideration of magnetic field fluctuation measurements in a torus plasma with heavy ion beam probe

International Nuclear Information System (INIS)

Shimizu, A.; Fujisawa, A.; Ohshima, S.; Nakano, H.

2004-03-01

The article discusses feasibility of magnetic fluctuation measurement with a heavy ion beam probe (HIBP) in an axisymmetric torus configuration. In the measurements, path integral fluctuation along the probing beam orbit should be considered as is similar to the density fluctuation measurements with HIBP. A calculation, based on an analytic formula, is performed to estimate the path integral effects for fluctuation patterns that have difference in profile, the correlation length, the radial wavelength, and the poloidal mode number. In addition, the large distance between the plasma and the detector is considered to lessen the path integral effect. As a result, it is found that local fluctuation of magnetic field can be properly detected with a heavy ion beam probe. (author)

Argonne inverted sputter source

International Nuclear Information System (INIS)

Yntema, J.L.; Billquist, P.J.

1983-01-01

The emittance of the inverted sputter source with immersion lenses was measured to be about 5π mm mrad MeV/sup 1/2/ at the 75% level over a wide range of beam intensities. The use of the source in experiments with radioactive sputter targets and hydrogen loaded targets is described. Self contamination of the source is discussed

Relation between the plasma characteristics and physical properties of functional zinc oxide thin film prepared by radio frequency magnetron sputtering process

International Nuclear Information System (INIS)

Hsu, Che-Wei; Cheng, Tsung-Chieh; Huang, Wen-Hsien; Wu, Jong-Shinn; Cheng, Cheng-Chih; Cheng, Kai-Wen; Huang, Shih-Chiang

2010-01-01

The ZnO thin film was deposited on a glass substrate by a RF reactive magnetron sputtering method. Results showed that plasma density, electron temperature, deposition rate and estimated ion bombardment energy increase with increasing applied RF power. Three distinct power regimes were observed, which are strongly correlated with plasma properties. In the low-power regime, the largest grain size was observed due to slow deposition rate. In the medium-power regime, the smallest grain size was found, which is attributed to insufficient time for the adatoms to migrate on substrate surface. In the high-power regime, relatively larger grain size was found due to very large ion bombardment energy which enhances the thermal migration of adatoms. Regardless of pure ZnO thin film or ZnO on glass, high transmittance (> 80%) in the visible region can be generally observed. However, the film thickness plays a more important role for controlling optical properties, especially in the UV region, than the applied RF power. In general, with properly coated ZnO thin film, we can obtain a glass substrate which is highly transparent in the visible region, is of good anti-UV characteristics, and is highly hydrophobic, which is highly suitable for applications in the glass industry.

Sputtering and reflection of self-bombardment of tungsten material

International Nuclear Information System (INIS)

Niu, Guo-jian; Li, Xiao-chun; Xu, Qian; Yang, Zhong-shi; Luo, Guang-nan

2015-01-01

In present research, the sputtering and reflection yield of self-bombardment of tungsten are investigated with the aid of molecular dynamics simulations. The source of sputtered and reflected atoms is detected by traced the original locations of sputtered and reflected atoms. Results show that for the reflected atoms no specific region exists which means cluster atoms are randomly reflected. But almost all of sputtered atoms are from a conical region under the landing point of cluster. So we can determine the sputtering yield by study the dimension of the sputtering region. Molecular dynamics shows the depth and radius of the conical are power functions of impacting energy. The effects of cluster size and temperature of target on sputtering and reflection rate are also preformed in present study. Both sputtering and reflection yield are proportion to cluster size in present cluster size, i.e. 66–2647 atoms. Higher target temperature can increase sputtering yield and deduce sputtering threshold energy, but little effect on reflection rate

Sputtering and reflection of self-bombardment of tungsten material

Energy Technology Data Exchange (ETDEWEB)

Niu, Guo-jian [University of Science and Technology of China, Hefei (China); Institute of Plasma Physics Chinese Academy of Sciences, Hefei (China); Li, Xiao-chun; Xu, Qian; Yang, Zhong-shi [Institute of Plasma Physics Chinese Academy of Sciences, Hefei (China); Luo, Guang-nan, E-mail: gnluo@ipp.ac.cn [University of Science and Technology of China, Hefei (China); Institute of Plasma Physics Chinese Academy of Sciences, Hefei (China); Hefei Center for Physical Science and Technology, Hefei (China); Hefei Science Center of CAS, Hefei (China)

2015-04-15

In present research, the sputtering and reflection yield of self-bombardment of tungsten are investigated with the aid of molecular dynamics simulations. The source of sputtered and reflected atoms is detected by traced the original locations of sputtered and reflected atoms. Results show that for the reflected atoms no specific region exists which means cluster atoms are randomly reflected. But almost all of sputtered atoms are from a conical region under the landing point of cluster. So we can determine the sputtering yield by study the dimension of the sputtering region. Molecular dynamics shows the depth and radius of the conical are power functions of impacting energy. The effects of cluster size and temperature of target on sputtering and reflection rate are also preformed in present study. Both sputtering and reflection yield are proportion to cluster size in present cluster size, i.e. 66–2647 atoms. Higher target temperature can increase sputtering yield and deduce sputtering threshold energy, but little effect on reflection rate.

Dwell time dependent morphological transition and sputtering yield of ion sputtered Sn

International Nuclear Information System (INIS)

Qian, H X; Zeng, X R; Zhou, W

2010-01-01

Self-organized nano-scale patterns may appear on a wide variety of materials irradiated with an ion beam. Good manipulation of these structures is important for application in nanostructure fabrication. In this paper, dwell time has been demonstrated to be able to control the ripple formation and sputtering yield on Sn surface. Ripples with a wavelength of 1.7 μm were observed for a dwell time in the range 3-20 μs, whereas much finer ripples with a wavelength of 540 nm and a different orientation were observed for a shorter dwell time in the range 0.1-2 μs. The sputtering yield increases with dwell time significantly. The results provide a new basis for further steps in the theoretical description of morphology evolution during ion beam sputtering.

Plasma cleaning of ITER First Mirrors in magnetic field

Energy Technology Data Exchange (ETDEWEB)

Moser, Lucas, E-mail: lucas.moser@unibas.ch [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Steiner, Roland [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland); Leipold, Frank; Reichle, Roger [ITER Organization, Route de Vinon-sur-Verdon, 13115 St Paul-lez-Durance (France); Marot, Laurent; Meyer, Ernst [Department of Physics, University of Basel, Klingelbergstrasse 82, CH-4056 Basel (Switzerland)

2015-08-15

To avoid reflectivity losses in ITER’s optical diagnostic systems, plasma sputtering of metallic First Mirrors is foreseen in order to remove deposits coming from the main wall (mainly beryllium and tungsten). Therefore plasma cleaning has to work on large mirrors (up to a size of 200 × 300 mm) and under the influence of strong magnetic fields (several Tesla). This work presents the results of plasma cleaning of aluminium and aluminium oxide (used as beryllium proxy) deposited on molybdenum mirrors. Using radio frequency (13.56 MHz) argon plasma, the removal of a 260 nm mixed aluminium/aluminium oxide film deposited by magnetron sputtering on a mirror (98 mm diameter) was demonstrated. 50 nm of pure aluminium oxide were removed from test mirrors (25 mm diameter) in a magnetic field of 0.35 T for various angles between the field lines and the mirrors surfaces. The cleaning efficiency was evaluated by performing reflectivity measurements, Scanning Electron Microscopy and X-ray Photoelectron Spectroscopy.

Sputtering effect of low-energy ions on biological target: The analysis of sputtering product of urea and capsaicin

International Nuclear Information System (INIS)

Zhang, Lili; Xu, Xue; Wu, Yuejin

2013-01-01

Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. Recent years, ion implantation was successfully applied to biological research based on the fragments sputtering and form open paths in cell structure caused by ion sputtering. In this study, we focused on urea and chilli pepper pericarp samples implanted with N + and Ar + ions. To investigate the sputtering effect, we designed a collecting unit containing a disk sample and a glass pipe. The urea content and capsaicin content recovered from glass pipes were adopted to represent the sputtering product. The result of urea showed that the sputtering effect is positively correlated with the ion energy and dose, also affected by the ion type. The result of capsaicin was different from that of urea at 20 keV and possibly due to biological complex composition and structure. Therefore the sputtering yield depended on both the parameters of incident ions and the state of target materials. The sputtering yield of urea was also simulated by computational method achieved through the TRIM program. The trajectories of primary and recoiled atoms were calculated on the basis of the binary collision approximation using Monte Carlo method. The experimental results were much higher than the calculated results. The possible explanation is that in the physical model the target were assumed as a disordered lattice and independent atoms, which is much less complicated than that of the biological models

Chemical sputtering of graphite by H+ ions

International Nuclear Information System (INIS)

Busharov, N.P.; Gorbatov, E.A.; Gusev, V.M.; Guseva, M.I.; Martynenko, Y.V.

1976-01-01

In a study of the sputtering coefficient S for the sputtering of graphite by 10-keV H + ions as a function of the graphite temperature during the bombardment, it is found that at T> or =750degreeC the coefficient S is independent of the target temperature and has an anomalously high value, S=0.085 atom/ion. The high rate of sputtering of graphite by atomic hydrogen ions is shown to be due to chemical sputtering of the graphite, resulting primarily in the formation of CH 4 molecules. At T=1100degreeC, S falls off by a factor of about 3. A model for the chemical sputtering of graphite is proposed

INFLUENCE OF LOW-ENERGY AR-SPUTTERING ON THE ELECTRONIC-PROPERTIES OF INAS-BASED QUANTUM-WELL STRUCTURES

NARCIS (Netherlands)

Magnee, P.H.C.; den Hartog, S.G.; Wees, B.J.van; Klapwijk, T.M; van de Graaf, W.; Borghs, G.

1995-01-01

The influence of low energy (80-500 eV) Ar-ion milling cleaning techniques on InAs based quantum well structures is investigated. It is found that both etching with a Kaufmann source and sputter-etching with a rf-plasma enhances the electron density and reduces the mobility. An anneal at 180 degrees

High levels of heavy metal accumulation in dental calculus of smokers: a pilot inductively coupled plasma mass spectrometry study.

Science.gov (United States)

Yaprak, E; Yolcubal, I; Sinanoğlu, A; Doğrul-Demiray, A; Guzeldemir-Akcakanat, E; Marakoğlu, I

2017-02-01

Various trace elements, including toxic heavy metals, may exist in dental calculus. However, the effect of environmental factors on heavy metal composition of dental calculus is unknown. Smoking is a major environmental source for chronic toxic heavy metal exposition. The aim of this study is to compare toxic heavy metal accumulation levels in supragingival dental calculus of smokers and non-smokers. A total of 29 supragingival dental calculus samples were obtained from non-smoker (n = 14) and smoker (n = 15) individuals. Subjects with a probability of occupational exposure were excluded from the study. Samples were analyzed by inductively coupled plasma mass spectrometry in terms of 26 metals and metalloids, including toxic heavy metals. Toxic heavy metals, arsenic (p 0.05). Within the limitations of this study, it can be concluded that the elementary composition of dental calculus may be affected by environmental factors such as tobacco smoke. Therefore, dental calculus may be utilized as a non-invasive diagnostic biological material for monitoring chronic oral heavy metal exposition. However, further studies are required to evaluate its diagnostic potential. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Computer simulation of sputtering: A review

International Nuclear Information System (INIS)

Robinson, M.T.; Hou, M.

1992-08-01

In 1986, H. H. Andersen reviewed attempts to understand sputtering by computer simulation and identified several areas where further research was needed: potential energy functions for molecular dynamics (MD) modelling; the role of inelastic effects on sputtering, especially near the target surface; the modelling of surface binding in models based on the binary collision approximation (BCA); aspects of cluster emission in MD models; and angular distributions of sputtered particles. To these may be added kinetic energy distributions of sputtered particles and the relationships between MD and BCA models, as well as the development of intermediate models. Many of these topics are discussed. Recent advances in BCA modelling include the explicit evaluation of the time in strict BCA codes and the development of intermediate codes able to simulate certain many-particle problems realistically. Developments in MD modelling include the wide-spread use of many-body potentials in sputtering calculations, inclusion of realistic electron excitation and electron-phonon interactions, and several studies of cluster ion impacts on solid surfaces

Heavy ion beam study of potential formation in bumpy torus plasma

International Nuclear Information System (INIS)

Takasugi, Keiichi.

1985-01-01

A heavy ion beam probe is constructed for the study of plasma confinement in Nagoya Bumpy Torus (NBT-1/1M). The measurement of the local plasma potential as well as the electron density profile is possible with good spatial (1 -- 2 cm) and temporal (-- 1 msec) resolutions. The feedback controlled detection technique and the time resolved fast detection technique are coupled to use, which enables us to measure local potential reliably even in the pulsed experiments. The process of the devlopment of concentric equipotential surface is observed. The cold and collisional plasma in bumpy torus is not in the equilibrium (C-mode), and the vertically polarized potential profile is produced by the toroidal drift. With the growth of warm collisionless electron component, the polarization is poloidally short-circuited, and the concentric equipotential surface is developed. The concentric negative potential well and its positive rim are observed in the standard operation. The position of the potential boundary (rim) moves with the second harmonic ECRH zone at the midplane of each mirror section, where the hot electron ring exists. The rim potential is formed by the direct loss of warm electrons. It is confirmed that the core electron heating is essential for the negative potential formation. The potential depth is much larger than the ion temperature Tsub(i), and cannot be explained by the existing neoclassical theory. A stable positive potential is observed near T-M transition. The positive potential is also observed in the ion heated plasma. Relating to the growth of the high energy component, the potential formation due to direct loss process is discussed. (author)

Advances and challenges in the field of plasma polymer nanoparticles

Directory of Open Access Journals (Sweden)

Andrei Choukourov

2017-09-01

Full Text Available This contribution reviews plasma polymer nanoparticles produced by gas aggregation cluster sources either via plasma polymerization of volatile monomers or via radio frequency (RF magnetron sputtering of conventional polymers. The formation of hydrocarbon, fluorocarbon, silicon- and nitrogen-containing plasma polymer nanoparticles as well as core@shell nanoparticles based on plasma polymers is discussed with a focus on the development of novel nanostructured surfaces.

Sputtering on cobalt with noble gas ions

International Nuclear Information System (INIS)

Sarholt-Kristensen, L.; Johansen, A.; Johnson, E.

1983-01-01

Single crystals of cobalt have been bombarded with 80 keV Ar + ions and with 80 keV and 200 keV Xe + ions in the [0001] direction of the hcp phase and the [111] direction of the fcc phase. The sputtering yield has been measured as function of target temperature (20 0 C-500 0 C), showing a reduction in sputtering yield for 80 keV Ar + ions and 200 keV Xe + ions, when the crystal structure changes from hcp to fcc. In contrast to this, bombardment with 80 keV Xe + ions results in an increase in sputtering yield as the phase transition is passed. Sputtering yields for [111] nickel are in agreement with the sputtering yields for fcc cobalt indicating normal behaviour of the fcc cobalt phase. The higher sputtering yield of [0001] cobalt for certain combinations of ion mass and energy may then be ascribed to disorder induced partly by martensitic phase transformation, partly by radiation damage. (orig.)

Electrical resistivity of sputtered molybdenum films

International Nuclear Information System (INIS)

Nagano, J.

1980-01-01

The electrical resistivity of r.f. sputtered molybdenum films of thickness 5-150 nm deposited on oxidized silicon substrates was resolved into the three electron scattering components: isotropic background scattering, scattering at grain boundaries and scattering at surfaces. It was concluded that the isotropic background scattering is almost equal to that of bulk molybdenum and is not influenced by sputtering and annealing conditions. When the film thickness is sufficient that surface scattering can be ignored, the decrease in film resistivity after annealing is caused by the decrease in scattering at the grain boundaries for zero bias sputtered films, and is caused by an increase of the grain diameter for r.f. bias sputtered films. (Auth.)

Thin films preparation of the Ti-Al-O system by rf-sputtering

International Nuclear Information System (INIS)

Montes de Oca, J. A.; Ceballos A, J.; Galaviz P, J.; Manaud, J. P.; Lahaye, M.; Munoz S, J.

2010-01-01

In the present work Ti-Al-O thin films were synthesized by rf-sputtering technique on glass and silicon (Si) substrates using Ti Al and Ti 3 Al targets in a sputtering chamber with an Ar-O 2 atmosphere. Ti-Al-O thin films were obtained varying experimental parameters such as oxygen percent fed to the reaction chamber, plasma power density and substrate temperature. The films deposited on glass substrates were used to evaluate their optical properties, while those deposited on Si substrates were used to evaluate mechanical and morphological properties. The crystalline structure, morphology, chemical composition and optical properties of the films were evaluated by X-ray diffraction, high-resolution scanning electron microscopy, Auger electron microscopy and visible UV spectroscopy. Films thicknesses were measured using a profiler. The roughness and mechanical properties such as hardness and Young modulus were analyzed by atomic force microscopy and nano indentation technique, respectively. (Author)

Plasma container

International Nuclear Information System (INIS)

Ebisawa, Katsuyuki.

1985-01-01

Purpose: To enable to easily detect that the thickness of material to be abraded is reduced to an allowable limit from the outerside of the plasma container even during usual operation in a plasma vessel for a thermonuclear device. Constitution: A labelled material is disposed to the inside or rear face of constituent members of a plasma container undergoing the irradiation of plasma particles. A limiter plate to be abraded in the plasma container is composed of an armour member and heat removing plate, in which the armour member is made of graphite and heat-removing plate is made of copper. If the armour member is continuously abraded under the effect of sputtering due to plasma particles, silicon nitride embedded so far in the graphite at last appears on the surface of the limiter plate to undergo the impact shocks of the plasma particles. Accordingly, abrasion of the limiter material can be detected by a detector comprising gas chromatography and it can easily be detected from the outside of the plasma content even during normal operation. (Horiuchi, T.)

Plasma-wall interactions

International Nuclear Information System (INIS)

Behrisch, Rainer

1978-01-01

The plasma wall interactions for two extreme cases, the 'vacuum model' and the 'cold gas blanket' are outlined. As a first step for understanding the plasma wall interactions the elementary interaction processes at the first wall are identified. These are energetic ion and neutral particle trapping and release, ion and neutral backscattering, ion sputtering, desorption by ions, photons and electrons and evaporation. These processes have only recently been started to be investigated in the parameter range of interest for fusion research. The few measured data and their extrapolation into regions not yet investigated are reviewed

Effects of plasma cleaning of the Cu seed layer surface on Cu electroplating

International Nuclear Information System (INIS)

O, Jun Hwan; Lee, Seong Wook; Kim, Jae Bum; Lee, Chong Mu

2001-01-01

Effects of plasma pretreatment to Cu seed/tantalum nitride (TaN)/ borophosphosilicate glass (BPSG) samples on copper (Cu) electroplating were investigated. Copper seed layers were deposited by magnetron sputtering onto tantalum nitride barrier layers before electroplating copper in the forward pulsed mode. The Cu seed layer was cleaned by plasma H 2 and N 2 prior to electroplating a copper film. Cu films electroplated on the copper seed layer with plasma pretreatment showed better electrical and physical properties such as electrical resistivities, surface morphologies, levels of impurities, adhesion and surface roughness than those without plasma pretreatment. It is shown that carbon and metal oxide contaminants at the sputtered Cu seed/TaN surface could be effectively removed by plasma H 2 cleaning. The degree of the (111) prefered orientation of the Cu film with plasma H 2 pretreatment is as high as pulse plated Cu film without plasma pretreatment. Also, plasma H 2 precleaning is more effective in enhancing the Cu electroplating properties onto the Cu seed layer than plasma N 2 precleaning

Examinations for the determination of the flux density of sputtered iron using laser induced fluorescence

International Nuclear Information System (INIS)

Schweer, H.B.

1983-11-01

In this work investigations are described to measure the flux density of sputtered iron atoms by means of laser induced fluorescence. In a laboratory experiment an iron target (stainless steel 316, Inconel 600), was bombarded with 10 keV Ar + and 2.5 keV H + and the population distribution of the energy levels of the ground state a 5 D and the metastable state a 5 F was measured. In the plasma wall region in the ISX-B tokamak at the Oak Ridge National Laboratory (USA) neutral iron atoms were measured the first time by laser induced fluorescence. A detection limit of 10 6 atoms/cm 3 was found and sputtered iron atoms were observed in the first 15 ms of the discharge. (orig./BRB)

Substantial difference in target surface chemistry between reactive dc and high power impulse magnetron sputtering

Science.gov (United States)

Greczynski, G.; Mráz, S.; Schneider, J. M.; Hultman, L.

2018-02-01

The nitride layer formed in the target race track during the deposition of stoichiometric TiN thin films is a factor 2.5 thicker for high power impulse magnetron sputtering (HIPIMS), compared to conventional dc processing (DCMS). The phenomenon is explained using x-ray photoelectron spectroscopy analysis of the as-operated Ti target surface chemistry supported by sputter depth profiles, dynamic Monte Carlo simulations employing the TRIDYN code, and plasma chemical investigations by ion mass spectrometry. The target chemistry and the thickness of the nitride layer are found to be determined by the implantation of nitrogen ions, predominantly N+ and N2+ for HIPIMS and DCMS, respectively. Knowledge of this method-inherent difference enables robust processing of high quality functional coatings.

Physical sputtering of metallic systems by charged-particle impact

International Nuclear Information System (INIS)

Lam, N.Q.

1989-12-01

The present paper provides a brief overview of our current understanding of physical sputtering by charged-particle impact, with the emphasis on sputtering of metals and alloys under bombardment with particles that produce knock-on collisions. Fundamental aspects of ion-solid interactions, and recent developments in the study of sputtering of elemental targets and preferential sputtering in multicomponent materials are reviewed. We concentrate only on a few specific topics of sputter emission, including the various properties of the sputtered flux and depth of origin, and on connections between sputtering and other radiation-induced and -enhanced phenomena that modify the near-surface composition of the target. The synergistic effects of these diverse processes in changing the composition of the integrated sputtered-atom flux is described in simple physical terms, using selected examples of recent important progress. 325 refs., 27 figs

Erosion and deuterium retention of CLF-1 steel exposed to deuterium plasma

Science.gov (United States)

Qiao, L.; Wang, P.; Hu, M.; Gao, L.; Jacob, W.; Fu, E. G.; Luo, G. N.

2017-12-01

In recent years reduced activation ferritic martensitic steel has been proposed as the plasma-facing material in remote regions of the first wall. This study reports the erosion and deuterium retention behaviours in CLF-1 steel exposed to deuterium (D) plasma in a linear experimental plasma system as function of incident ion energy and fluence. The incident D ion energy ranges from 30 to 180 eV at a flux of 4 × 1021 D m-2 s-1 up to a fluence of 1025 D m-2. SEM images revealed a clear change of the surface morphology as functions of incident fluence and impinging energy. The mass loss results showed a decrease of the total sputtering yield of CLF-1 steel with increasing incident fluence by up to one order of magnitude. The total sputtering yield of CLF-1 steel after 7.2 × 1024 D m-2 deuterium plasma exposure reduced by a factor of 4 compared with that of pure iron, which can be attributed to the enrichment of W at the surface due to preferential sputtering of iron and chromium. After D plasma exposure, the total deuterium retention in CLF-1 steel samples measured by TDS decreased with increasing incident fluence and energy, and a clear saturation tendency as function of incident fluence or energy was also observed.

Preparation of CIGS thin films by HiPIMS or DC sputtering and various selenization processes

Czech Academy of Sciences Publication Activity Database

Olejníček, Jiří; Hubička, Zdeněk; Kšírová, Petra; Kment, Štěpán; Brunclíková, Michaela; Kohout, Michal; Čada, Martin; Darveau, S.A.; Exstrom, C.L.

2013-01-01

Roč. 16, č. 2 (2013), s. 314-319 ISSN 1203-8407 R&D Projects: GA MŠk LH12045 Institutional support: RVO:68378271 Keywords : CIGS * HIPIMS * selenization * nanocrystals * solar energy * sputtering * thin films Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.106, year: 2013 http://www.ingentaconnect.com/content/stn/jaots/2013/00000016/00000002/art00015

Electrical insulation properties of RF-sputtered LiPON layers towards electrochemical stability of lithium batteries

OpenAIRE

Vieira, E. M. F.; Ribeiro, J. F.; Silva, Maria Manuela; Barradas, N. P.; Alves, E.; Alves, A.; Correia, M. R.; Gonçalves, L. M.

2016-01-01

Electrochemical stability, moderate ionic conductivity and low electronic conductivity make the lithium phosphorous oxynitride (LiPON) electrolyte suitable for micro and nanoscale lithium batteries. The electrical and electrochemical properties of thin-film electrolytes can seriously compromise full battery performance. Here, radio-frequency (RF)-sputtered LiPON thin films were fabricated in nitrogen plasma under different working pressure conditions. With a slight decrease in ...

Characterization of sp3 bond content of carbon films deposited by high power gas injection magnetron sputtering method by UV and VIS Raman spectroscopy

Science.gov (United States)

Zdunek, Krzysztof; Chodun, Rafał; Wicher, Bartosz; Nowakowska-Langier, Katarzyna; Okrasa, Sebastian

2018-04-01

This paper presents the results of investigations of carbon films deposited by a modified version of the magnetron sputtering method - HiPGIMS (High Power Gas Injection Magnetron Sputtering). In this experiment, the magnetron system with inversely polarized electrodes (sputtered cathode at ground potential and positively biased, spatially separated anode) was used. This arrangement allowed us to conduct the experiment using voltages ranging from 1 to 2 kV and a power supply system equipped with 25/50 μF capacitor battery. Carbon films were investigated by VIS/UV Raman spectroscopy. Sp3/sp2 bonding ratio was evaluated basing the elementary components of registered spectra. Our investigation showed that sp3 bond content increases with discharge power but up to specific value only. In extreme conditions of generating plasma impulses, we detected a reversed relation of the sp3/sp2 ratio. In our opinion, a energy of plasma pulse favors nucleation of a sp3 phase because of a relatively higher ionization state but in extreme cases the influence of energy is reversed.

Characterization of sp3 bond content of carbon films deposited by high power gas injection magnetron sputtering method by UV and VIS Raman spectroscopy.

Science.gov (United States)

Zdunek, Krzysztof; Chodun, Rafał; Wicher, Bartosz; Nowakowska-Langier, Katarzyna; Okrasa, Sebastian

2018-04-05

This paper presents the results of investigations of carbon films deposited by a modified version of the magnetron sputtering method - HiPGIMS (High Power Gas Injection Magnetron Sputtering). In this experiment, the magnetron system with inversely polarized electrodes (sputtered cathode at ground potential and positively biased, spatially separated anode) was used. This arrangement allowed us to conduct the experiment using voltages ranging from 1 to 2kV and a power supply system equipped with 25/50μF capacitor battery. Carbon films were investigated by VIS/UV Raman spectroscopy. Sp 3 /sp 2 bonding ratio was evaluated basing the elementary components of registered spectra. Our investigation showed that sp 3 bond content increases with discharge power but up to specific value only. In extreme conditions of generating plasma impulses, we detected a reversed relation of the sp 3 /sp 2 ratio. In our opinion, a energy of plasma pulse favors nucleation of a sp 3 phase because of a relatively higher ionization state but in extreme cases the influence of energy is reversed. Copyright © 2018 Elsevier B.V. All rights reserved.

High-rate deposition of Ta-doped SnO2 films by reactive magnetron sputtering using a Sn–Ta metal-sintered target

International Nuclear Information System (INIS)

Muto, Y.; Nakatomi, S.; Oka, N.; Iwabuchi, Y.; Kotsubo, H.; Shigesato, Y.

2012-01-01

Ta-doped SnO 2 films were deposited on glass substrate (either unheated or heated at 200 °C) by reactive magnetron sputtering with a Sn–Ta metal-sintered target using a plasma control unit (PCU) and mid-frequency (mf, 50 kHz) unipolar pulsing. The PCU feedback system precisely controlled the flow of the reactive and sputtering gases (O 2 and Ar, respectively) by monitoring either discharge impedance or the plasma emission of the atomic O* line at 777 nm. The planar target was connected to the switching unit, which was operated in unipolar pulse mode. Power density on the target was maintained at 4.4 W cm −2 during deposition. The lowest obtained resistivity for the films deposited on heated substrate was 6.4 × 10 −3 Ωcm, where the deposition rate was 250 nm min −1 .

A review of basic phenomena and techniques for sputter-deposition of high temperature superconducting films

Energy Technology Data Exchange (ETDEWEB)

Auciello, O. (Microelectronics Center of North Carolina, Research Triangle Park, NC (USA) North Carolina State Univ., Raleigh, NC (USA). Dept. of Materials Science and Engineering); Ameen, M.S.; Kingon, A.I.; Lichtenwalner, D.J. (North Carolina State Univ., Raleigh, NC (USA). Dept. of Materials Science and Engineering); Krauss, A.R. (Argonne National Lab., IL (USA))

1990-01-01

The processes involved in plasma and ion beam sputter-deposition of high temperature superconducting thin films are critically reviewed. Recent advances in the development of these techniques are discussed in relation to basic physical phenomena, specific to each technique, which must be understood before high quality films can be produced. Control of film composition is a major issue in sputter-deposition of multicomponent materials. Low temperature processing of films is a common goal for each technique, particularly in relation to integrating high temperature superconducting films with the current microelectronics technology. It has been understood for some time that for Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} deposition, the most intensely studied high-{Tc} compound, incorporation of sufficient oxygen into the film during deposition is necessary to produce as-deposited superconducting films at relatively substrate temperatures. Recent results have shown that with the use of suitable buffer layers, high quality Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} sputtered films can be obtained on Si substrates without the need for post-deposition anneal processing. This review is mainly focussed on issues related to sputter-deposition of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} thin films, although representative results concerning the bismuth and thallium based compounds are included. 143 refs., 11 figs.

Nylon-sputtered nanoparticles: fabrication and basic properties

Science.gov (United States)

Polonskyi, O.; Kylián, O.; Solař, P.; Artemenko, A.; Kousal, J.; Slavínská, D.; Choukourov, A.; Biederman, H.

2012-12-01

Nylon-sputtered nanoparticles were prepared using a simple gas aggregation cluster source based on a planar magnetron (Haberland type) and equipped with a nylon target. Plasma polymer particles originated in an aggregation chamber and travelled to a main (deposition) chamber with a gas flow through an orifice. The deposited nanoparticles were observed to have a cauliflower-like structure. The nanoparticles were found to be nitrogen-rich with N/C ratio close to 0.5. An increase in rf power from 60 to 100 W resulted in a decrease in mean particle size from 210 to 168 nm whereas an increase in their residence time in the cluster source from 0.7 to 4.6 s resulted in an increase in the size from 73 to 231 nm.

Sputtering calculations with the discrete ordinated method

International Nuclear Information System (INIS)

Hoffman, T.J.; Dodds, H.L. Jr.; Robinson, M.T.; Holmes, D.K.

1977-01-01

The purpose of this work is to investigate the applicability of the discrete ordinates (S/sub N/) method to light ion sputtering problems. In particular, the neutral particle discrete ordinates computer code, ANISN, was used to calculate sputtering yields. No modifications to this code were necessary to treat charged particle transport. However, a cross section processing code was written for the generation of multigroup cross sections; these cross sections include a modification to the total macroscopic cross section to account for electronic interactions and small-scattering-angle elastic interactions. The discrete ordinates approach enables calculation of the sputtering yield as functions of incident energy and angle and of many related quantities such as ion reflection coefficients, angular and energy distributions of sputtering particles, the behavior of beams penetrating thin foils, etc. The results of several sputtering problems as calculated with ANISN are presented

Comparative study of the characteristics of Ni films deposited on SiO2/Si(100) by oblique-angle sputtering and conventional sputtering

International Nuclear Information System (INIS)

Yu Mingpeng; Qiu Hong; Chen Xiaobai; Wu Ping; Tian Yue

2008-01-01

Ni films were deposited on SiO 2 /Si(100) substrates at 300 K and 573 K by oblique-angle sputtering and conventional sputtering. The films deposited at 300 K mainly have a [110] crystalline orientation in the growing direction whereas those deposited at 573 K grow with a [111] crystalline orientation in the growing direction. The film prepared only at 300 K by oblique-angle sputtering grows with a weakly preferential orientation along the incidence direction of the sputtered Ni atoms. All the films grow with thin columnar grains perpendicular to the substrate surface. The grain size of the films sputter-deposited obliquely is larger than that of the films sputter-deposited conventionally. The grain size of the Ni film does not change markedly with the deposition temperature. The film deposited at 573 K by oblique-angle sputtering has the highest saturation magnetization. For the conventional sputtering, the coercivity of the Ni film deposited at 573 K is larger than that of the film deposited at 300 K. However, for the oblique-angle sputtering, the coercivity of the Ni film is independent of the deposition temperature. All the Ni films exhibit an isotropic magnetization characteristic in the film plane

Transport theory of sputtering I: Depth of origin of sputtered atoms

International Nuclear Information System (INIS)

Zhang, Zhu Lin

1999-01-01

Sputter theory employing a sum of two power cross sections has been implemented. Compared with the well known Lindhard power cross section (V∝r -1/m ), a sum of two such cross sections can give a much better approximation to the Born-Mayer scattering in the low energy region (m ∼ 0.1). By using both one and two power cross sections, we have solved the linear transport equations describing the sputtering problem asymptotically. As usual, electronic stopping is ignored in the analysis. It has further been proved that Falcone's theory of the atom ejection process contradicts transport theory. The Andersen-Sigmund relation for partial sputtering yield ratios between two elements in an arbitrary multicomponent target has been derived by both methods. The energy deposited in the target surface layers has been computed for a few typical ion-target combinations. The numerical curves show that both theories generate almost the same results (error m≥0. The former even may be only about one half of the latter as long as m=0

Evaluation of composition, mechanical properties and structure of nc-TiC/a-C:H coatings prepared by balanced magnetron sputtering

Czech Academy of Sciences Publication Activity Database

Souček, P.; Schmidtová, T.; Zábranský, L.; Buršíková, V.; Vašina, P.; Caha, O.; Jílek, M.; Abdelazziz, El Mel.; Tessier, P.Y.; Schäfer, J.; Buršík, Jiří; Peřina, Vratislav; Mikšová, Romana

2012-01-01

Roč. 211, OCT 25 (2012), s. 111-116 ISSN 0257-8972 Institutional support: RVO:68081723 ; RVO:61389005 Keywords : nanocomposite * magnetron sputtering * titanium Subject RIV: JI - Composite Materials; BL - Plasma and Gas Discharge Physics (UJF-V) Impact factor: 1.941, year: 2012

Sputtering induced surface composition changes in copper-palladium alloys

International Nuclear Information System (INIS)

Sundararaman, M.; Sharma, S.K.; Kumar, L.; Krishnan, R.

1981-01-01

It has been observed that, in general, surface composition is different from bulk composition in multicomponent materials as a result of ion beam sputtering. This compositional difference arises from factors like preferential sputtering, radiation induced concentration gradients and the knock-in effect. In the present work, changes in the surface composition of copper-palladium alloys, brought about by argon ion sputtering, have been studied using Auger electron spectroscopy. Argon ion energy has been varied from 500 eV to 5 keV. Enrichment of palladium has been observed in the sputter-altered layer. The palladium enrichment at the surface has been found to be higher for 500 eV argon ion sputtering compared with argon ion sputtering at higher energies. Above 500 eV, the surface composition has been observed to remain the same irrespective of the sputter ion energy for each alloy composition. The bulk composition ratio of palladium to copper has been found to be linearly related to the sputter altered surface composition ratio of palladium to copper. These results are discussed on the basis of recent theories of alloy sputtering. (orig.)

Plasma lens focusing and plasma channel transport for heavy ion fusion

International Nuclear Information System (INIS)

Tauschwitz, A.; Yu, S.S.; Bangerter, R.O.

1996-01-01

The final focus lens in an ion beam driven inertial confinement fusion reactor is important since it sets limiting requirements for the quality of the driver beam. Improvements of the focusing capabilities can facilitate the construction of the driver significantly. A focusing system that is of interest both for heavy ion and for light ion drivers is an adiabatic, current carrying plasma lens. This lens is characterized by the fact that it can slowly (adiabatically) reduce the envelope radius of a beam over several betatron oscillations by increasing the focusing magnetic field along a tapered high current discharge. A reduction of the beam diameter by a factor of 3 to 5 seems feasible with this focusing scheme. Such a lens can be used for an ignition test facility where it can be directly coupled to the fusion target. For use in a repetitively working reactor chamber the lens has to be located outside of the reactor and the tightly focused but strongly divergent beam must be confined in a high current transport channel from the end of the lens into the immediate vicinity of the target. Laser preionization of a background gas is an efficient means to direct and stabilize such a channel. Experiments have been started to test both, the principle of adiabatic focusing, and the stability of laser preionized high current discharge channels. (author). 4 figs., 7 refs

Plasma lens focusing and plasma channel transport for heavy ion fusion

Energy Technology Data Exchange (ETDEWEB)

Tauschwitz, A; Yu, S S; Bangerter, R O [Lawrence Berkeley Lab., CA (United States); and others

1997-12-31

The final focus lens in an ion beam driven inertial confinement fusion reactor is important since it sets limiting requirements for the quality of the driver beam. Improvements of the focusing capabilities can facilitate the construction of the driver significantly. A focusing system that is of interest both for heavy ion and for light ion drivers is an adiabatic, current carrying plasma lens. This lens is characterized by the fact that it can slowly (adiabatically) reduce the envelope radius of a beam over several betatron oscillations by increasing the focusing magnetic field along a tapered high current discharge. A reduction of the beam diameter by a factor of 3 to 5 seems feasible with this focusing scheme. Such a lens can be used for an ignition test facility where it can be directly coupled to the fusion target. For use in a repetitively working reactor chamber the lens has to be located outside of the reactor and the tightly focused but strongly divergent beam must be confined in a high current transport channel from the end of the lens into the immediate vicinity of the target. Laser preionization of a background gas is an efficient means to direct and stabilize such a channel. Experiments have been started to test both, the principle of adiabatic focusing, and the stability of laser preionized high current discharge channels. (author). 4 figs., 7 refs.

Heavy Neutral Beam Probe for edge plasma analysis in Tokamaks

International Nuclear Information System (INIS)

Castracane, J.; Saravia, E.; Beckstead, J.; Aceto, S.

1993-01-01

The contents of this report present the progress achieved to date on the Heavy Neutral Beam Probe project. This effort is an international collaboration in magnetic confinement fusion energy research sponsored by the US Department of Energy, Office of Energy Research (Confinement Systems Division) and the Centre Canadien de Fusion Magnetique (CCFM). The overall objective of the effort is to develop and apply a neutral particle beam to the study of edge plasma dynamics in discharges on the Tokamak de Varennes (TdeV) facility in Montreal, Canada. To achieve this goal, a research and development project was established to produce the necessary hardware to make such measurements and meet the scheduling requirements of the program. At present the project is in the middle of its second budget period with the instrumentation on-site at TdeV. The first half of this budget period was used to complete total system tests at InterScience, Inc., dismantle and ship the hardware to TdeV, re-assemble and install the HNBP on the tokamak. Integration of the diagnostic into the TdeV facility has progressed to the point of first beam production and measurement on the plasma. At this time, the HNBP system is undergoing final de-bugging prior to re-start of machine operation in early Fall of this year

Krypton-85 storage in sputter-deposited amorphous metals

International Nuclear Information System (INIS)

Tingey, G.L.; McClanahan, E.D.; Lytle, J.M.; Gordon, N.R.; Knoll, R.W.

1982-06-01

After comparing options for storing radioactive krypton gas, the United States Department of Energy selected ion implantation of the gas into a sputter-deposited metal matrix as the reference process. This technique is being developed with pilot-scale testing and further characterization of the deposited product. The process involves implanting krypton atoms into a growing deposit during the sputtering process. An amorphous metal deposit of nominal composition Ni 0 81 La 0 09 Kr 0 10 has been selected for further studies because of the high krypton loading, high sputtering yield, relatively low cost of the metallic components, resistance to corrosion, and stability of the product. The krypton release from this amorphous metal is described as an activated diffusion process which increases linearly with the square root of time. Studies of krypton release rate as a function of temperature were completed and an activation energy for the diffusion of 70 kcal/mole obtained. From these data, we estimated that the krypton release during the first ten years would be 0.5% for a maximum temperature of 350 0 C. The actual release of the krypton during storage was projected to be lower by a factor of 10 7 with the maximum temperature only 220 0 C. Thermal analysis studies show two energy releases occurring with krypton-containing alloys: one associated with recrystallization of the amorphous alloy and a second associated with krypton release. The total energy release between 100 and 800 0 C was less than 50 cal/g. Estimates are given for the cost of operation of the ion implantation process for solidification of the krypton-85 from a 2000-tonne heavy metal/year reprocessing plant. The present value costs, in 1981 dollars including capital and operating costs and assuming a 30-year life, are about $26M for the lifetime of the plant. Annual energy consumption of the process was estimated to be 3.9 M kWh/year

Laterally resolved ion-distribution functions at the substrate position during magnetron sputtering of indium-tin oxide films

International Nuclear Information System (INIS)

Plagemann, A.; Ellmer, K.; Wiesemann, K.

2007-01-01

During the magnetron sputtering from an indium-tin oxide (ITO) target (76 mm diameter) we measured the ion-distribution functions (IDFs) of energetic ions (argon, indium, and oxygen ions) at the substrate surface using a combination of a quadrupole mass spectrometer and an electrostatic energy analyzer. We obtained the IDFs for argon sputtering pressures in the range from 0.08 to 2 Pa and for dc as well as rf (13.56 MHz) plasma excitation with powers from 10 to 100 W. The IDF measurements were performed both over the target center at a target-to-substrate distance of 65 mm and at different positions along the target radius in order to scan the erosion track of the target. The mean kinetic energies of argon ions calculated from the IDFs in the dc plasma decreased from about 30 to 15 eV, when the argon pressure increased from 0.08 to 2 Pa, which is caused by a decrease of the electron temperature also by a factor of 2. Indium atoms exhibit higher mean energies due to their additional energy from the sputtering process. The total metal ion flux turns out to be proportional to the discharge power and the pressure, the latter dependence being due to Penning ionization of the metal atoms (In and Sn). From the scans across the target surface the lateral distributions of metal, oxygen, and argon ions were derived. In the dc discharge the position of the erosion track is reproduced by increased ion intensities, while it is not the case for the rf excited plasma. The lateral variations of the observed species do not influence the lateral resistivity distributions of the deposited ITO films

Deposition and surface treatment of Ag-embedded indium tin oxide by plasma processing

International Nuclear Information System (INIS)

Kim, Jun Young; Kim, Jae-Kwan; Kim, Ja-Yeon; Kwon, Min-Ki; Yoon, Jae-Sik; Lee, Ji-Myon

2013-01-01

Ag-embedded indium tin oxide (ITO) films were deposited on Corning 1737 glass by radio-frequency magnetron sputtering under an Ar or Ar/O 2 mixed gas ambient with a combination of ITO and Ag targets that were sputtered alternately by switching on and off the shutter of the sputter gun. The effects of a subsequent surface treatment using H 2 and H 2 + O 2 mixed gas plasma were also examined. The specific resistance of the as-deposited Ag-embedded ITO sample was lower than that of normal ITO. The transmittance was quenched when Ag was incorporated in ITO. To enhance the specific resistance of Ag-embedded ITO, a surface treatment was conducted using H 2 or H 2 + O 2 mixed gas plasma. Although all samples showed improved specific resistance after the H 2 plasma treatment, the transmittance was quenched due to the formation of agglomerated metals on the surface. The specific resistance of the film was improved without any deterioration of the transmittance after a H 2 + O 2 mixed gas plasma treatment. - Highlights: • Ag-embedded indium tin oxide was deposited. • The contact resistivity was decreased by H 2 + O 2 plasma treatment. • The process was carried out at room temperature without thermal treatment. • The mechanism of enhancing the contact resistance was clarified

MD simulation of cluster formation during sputtering

International Nuclear Information System (INIS)

Muramoto, T.; Okai, M.; Yamashita, Y.; Yorizane, K.; Yamamura, Y.

2001-01-01

The cluster ejection due to cluster impact on a solid surface is studied through molecular dynamics (MD) simulations. Simulations are performed for Cu cluster impacts on the Cu(1 1 1) surface for cluster energy 100 eV/atom, and for clusters of 6, 13, 28 and 55 atoms. Interatomic interactions are described by the AMLJ-EAM potential. The vibration energy spectrum is independent of the incident cluster size and energy. This comes from the fact that sputtered clusters become stable through the successive fragmentation of nascent large sputtered clusters. The vibration energy spectra for large sputtered clusters have a peak, whose energy corresponds to the melting temperature of Cu. The exponent of the power-law fit of the abundance distribution and the total sputtering yield for the cluster impacts are higher than that for the monatomic ion impacts with the same total energy, where the exponent δ is given by Y n ∝n δ and Y n is the yield of sputtered n-atom cluster. The exponent δ follows a unified function of the total sputtering yield, which is a monotonic increase function, and it is nearly equal to δ ∼ -3 for larger yield

Influence of redeposition on the plasma etching dynamics

International Nuclear Information System (INIS)

Stafford, L.; Margot, J.; Delprat, S.; Chaker, M.; Pearton, S. J.

2007-01-01

This work reports on measurements of the degree of redeposition of sputtered species during the etching of platinum (Pt), barium-strontium-titanate (BST), strontium-bismuth-tantalate (SBT), and photoresist (PR) in a high-density argon plasma. While PR exhibits a redeposition-free behavior, the degree of redeposition of Pt, BST, and SBT species increases from 10% to 95% as the argon pressure increases from 0.5 to 10 mTorr. These results are in good agreement with the predictions of a simple model accounting for the backscattering of sputtered species following their interaction with the gas phase. Based on these results and using other experimental data reported in the literature, it is further demonstrated that, depending on the plasma etching conditions, redeposition effects can induce misinterpretation of the etch rate data

Experimental and analytical study of the sputtering phenomena

International Nuclear Information System (INIS)

Howard, P.A.

1976-03-01

One form of the sputtering phenomena, the heat-transfer process that occurs when an initially hot vertical surface is cooled by a falling liquid film, was examined from a new experimental approach. The sputtering front is the lowest wetted position on the vertical surface and is characterized by a short region of intense nucleate boiling. The sputtering front progresses downward at nearly a constant rate, the surface below the sputtering front being dry and almost adiabatic. This heat-transfer process is of interest in the analysis of some of the performance aspects of emergency core-cooling systems of light-water reactors. An experimental apparatus was constructed to examine the heat-transfer characteristics of a sputtering front. In the present study, a heat source of sufficient intensity was located immediately below the sputtering front, which prevented its downward progress, thus permitting detailed measurements of steady-state surface temperatures throughout a sputtering front. Experimental evidence showed the sputtering front to correspond to a critical heat-flux (CHF) phenomenon. Data were obtained with water flow rates of 350-1600 lb/sub m//hr-ft and subcoolings of 40-140 0 F on a 3 / 8 -in. solid copper rod at 1 atm. A two-dimensional analytical model was developed to describe a stationary sputtering front where the wet-dry interface corresponds to a CHF phenomena and the dry zone is adiabatic. This model is nonlinear because of the temperature dependence of the heat-transfer coefficient in the wetted region and has yielded good agreement with data. A simplified one-dimensional approximation was developed which adequately describes these data. Finally, by means of a coordinate transformation and additional simplifying assumptions, this analysis was extended to analyze moving sputtering fronts, and reasonably good agreement with reported data was shown

High-density plasma etching characteristics of indium-gallium-zinc oxide thin films in CF4/Ar plasma

International Nuclear Information System (INIS)

Joo, Young-Hee; Kim, Chang-Il

2015-01-01

We investigated the etching process of indium-gallium-zinc oxide (IGZO) thin films in an inductively coupled plasma system. The dry etching characteristics of the IGZO thin films were studied by varying the CF 4 /Ar gas mixing ratio, RF power, DC-bias voltage, and process pressure. We determined the following optimized process conditions: an RF power of 700 W, a DC-bias voltage of − 150 V, and a process pressure of 2 Pa. A maximum etch rate of 25.63 nm/min for the IGZO thin films was achieved in a plasma with CF 4 /Ar(= 25:75), and the selectivity of IGZO to Al and TiN was found to be 1.3 and 0.7, respectively. We determined the ionic composition of the CF 4 /Ar plasma using optical emission spectroscopy. Analysis of chemical reactions at the IGZO thin film surfaces was performed using X-ray photoelectron spectroscopy. - Highlights: • IGZO thin film was etched by CF 4 /Ar plasma as a function of gas mixing ratio. • IGZO bonds were broken Ar + sputtering and then reacted with the C-F x radicals. • The physical sputtering is dominant in etch control compared with chemical etching

Measurements of beryllium sputtering yields at JET

Science.gov (United States)

Jet-Efda Contributors Stamp, M. F.; Krieger, K.; Brezinsek, S.

2011-08-01

The lifetime of the beryllium first wall in ITER will depend on erosion and redeposition processes. The physical sputtering yields for beryllium (both deuterium on beryllium (Be) and Be on Be) are of crucial importance since they drive the erosion process. Literature values of experimental sputtering yields show an order of magnitude variation so predictive modelling of ITER wall lifetimes has large uncertainty. We have reviewed the old beryllium yield experiments on JET and used current beryllium atomic data to produce revised beryllium sputtering yields. These experimental measurements have been compared with a simple physical sputtering model based on TRIM.SP beryllium yield data. Fair agreement is seen for beryllium yields from a clean beryllium limiter. However the yield on a beryllium divertor tile (with C/Be co-deposits) shows poor agreement at low electron temperatures indicating that the effect of the higher sputtering threshold for beryllium carbide is important.

Co-sputtered optical films

Energy Technology Data Exchange (ETDEWEB)

Misiano, C; Simonetti, E [Selenia S.p.A., Rome (Italy)

1977-06-01

The co-sputtering of two dielectric materials with indices of refraction as widely different as possible has been investigated with the aim of obtaining both homogeneous films with an intermediate index of refraction and inhomogeneous films with predetermined profiles. An rf sputtering module is described which has been especially designed, with two separate cathodes and two independent tunable rf generators. The substrates are placed on a circular anode rotating underneath the two cathodes. So far mainly CeO/sub 2/, TiO2 and SiO/sub 2/ targets have been used. The deposition rate from each cathode and the total film thickness are determined by means of two quartz thickness monitors, sputtering compatible. Values obtained for the refractive index and optical thickness are reported, as well as repeatability, mechanical and chemical characteristics, reliability and high power optical radiation resistance. Finally, results obtained on optical components of practical interest are discussed.

Laser micromachining of sputtered DLC films

International Nuclear Information System (INIS)

Fu, Y.Q.; Luo, J.K.; Flewitt, A.J.; Ong, S.E.; Zhang, S.; Milne, W.I.

2006-01-01

DLC films with different thicknesses (from 100 nm to 1.9 μm) were deposited using sputtering of graphite target in pure argon atmosphere without substrate heating. Film microstructures (sp 2 /sp 3 ratio) and mechanical properties (modulus, hardness, stress) were characterized as a function of film thickness. A thin layer of aluminum about 60 nm was deposited on the DLC film surface. Laser micromachining of Al/DLC layer was performed to form microcantilever structures, which were released using a reactive ion etching system with SF 6 plasma. Due to the intrinsic stress in DLC films and bimorph Al/DLC structure, the microcantilevers bent up with different curvatures. For DLC film of 100 nm thick, the cantilever even formed microtubes. The relationship between the bimorph beam bending and DLC film properties (such as stress, modulus, etc.) were discussed in details

Heavy flavours in ultra-relativistic heavy ions collisions

International Nuclear Information System (INIS)

Rosnet, Ph.

2008-01-01

The ultra-relativistic collisions of heavy ions are the today's only means to tackle in laboratory conditions the phase diagram in quantum chromodynamics and the strong interaction. The most recent theoretical studies predict a phase transition between the cold nuclear matter (a hadronic gas) and a plasma of quarks and gluons. Heavy flavour can characterize the nuclear matter produced in a heavy ion collision as well as its spatial-temporal evolution. Their study can be made through their decay into muons. The first part of this work presents the issue of ultra-relativistic heavy ion collisions and the role of heavy flavours. In the second part the author reviews the results of experiments performed at RHIC and particularly presents the analysis of the mass spectrum of dimuons in the Phenix experiment. The third part describes the muon trigger system of the Alice experiment at CERN and the expected performances for the study of di-muons

Preparation and comparison of a-C:H coatings using reactive sputter techniques

Energy Technology Data Exchange (ETDEWEB)

Keunecke, M., E-mail: martin.keunecke@ist.fraunhofer.d [Fraunhofer Institute for Surface Engineering and Thin Films (IST), Braunschweig (Germany); Weigel, K.; Bewilogua, K. [Fraunhofer Institute for Surface Engineering and Thin Films (IST), Braunschweig (Germany); Cremer, R.; Fuss, H.-G. [CemeCon AG, Wuerselen (Germany)

2009-12-31

Amorphous hydrogenated carbon (a-C:H) coatings are widely used in several industrial applications. These coatings commonly will be prepared by plasma activated chemical vapor deposition (PACVD). The main method used to prepare a-C:H coating in industrial scale is based on a glow discharge in a hydrocarbon gas like acetylene or methane using a substrate electrode powered with medium frequency (m.f. - some 10 to 300 kHz). Some aims of further development are adhesion improvement, increase of hardness and high coating quality on complex geometries. A relatively new and promising technique to fulfil these requirements is the deposition of a-C:H coatings by a reactive d.c. magnetron sputter deposition from a graphite target with acetylene as reactive gas. An advancement of this technique is the deposition in a pulsed magnetron sputter process. Using these three mentioned techniques a-C:H coatings were prepared in the same deposition machine. For adhesion improvement different interlayer systems were applied. The effect of different substrate bias voltages (d.c. and d.c. pulse) was investigated. By applying the magnetron sputter technique in the d.c. pulse mode, plastic hardness values up to 40 GPa could be reached. Besides hardness other mechanical properties like resistance against abrasive wear were measured and compared. Cross sectional SEM images showed the growth structure of the coatings.

Laser sputtering. Pt. 1

International Nuclear Information System (INIS)

Kelly, R.; Cuomo, J.J.; Leary, P.A.; Rothenburg, J.E.; Braren, B.E.; Aliotta, C.F.

1985-01-01

Irradiation, i.e. bombardment, with 193 nm laser pulses having an energy fluence of 2.5 J/cm 2 and a duration of proportional12 ns leads to rapid sputtering with Au, Al 2 O 3 , MgO, MgO.Al 2 O 3 , SiO 2 , glass, and LaB 6 , relatively slow sputtering with MgF 2 and diamond, and mainly thermal-stress cracking with W. Scanning electron microscopy (SEM) suggests that the mechanism for the sputtering of Au in either vacuum or air is one based on the hydrodynamics of molten Au, while an SEM-derived surface temperature estimate confirms that thermal sputtering (which might have been expected) is not possible. SEM with W shows that the near total lack of material removal is due to the thermal-stress cracking not leading to completed exfoliation, together with the surface temperature being too low for either hydrodynamical or thermal processes. Corresponding SEM with Al 2 O 3 shows, in the case of specimens bombarded in vacuum, topography of such a type that all mechanisms except electronic ones can be ruled out. The topography of Al 2 O 3 or other oxides bombarded in air through a mask is somewhat different, showing craters as for vacuum bombardments but ones which have a cone-like pattern on the bottom. (orig.)

Sputtering materials for VLSI and thin film devices

CERN Document Server

Sarkar, Jaydeep

2010-01-01

An important resource for students, engineers and researchers working in the area of thin film deposition using physical vapor deposition (e.g. sputtering) for semiconductor, liquid crystal displays, high density recording media and photovoltaic device (e.g. thin film solar cell) manufacturing. This book also reviews microelectronics industry topics such as history of inventions and technology trends, recent developments in sputtering technologies, manufacturing steps that require sputtering of thin films, the properties of thin films and the role of sputtering target performance on overall p

Soft Gluon Radiation off Heavy Quarks beyond Eikonal Approximation

International Nuclear Information System (INIS)

Mazumder, Surasree; Bhattacharyya, Trambak; Abir, Raktim

2016-01-01

We calculate the soft gluon radiation spectrum off heavy quarks (HQs) interacting with light quarks (LQs) beyond small angle scattering (eikonality) approximation and thus generalize the dead-cone formula of heavy quarks extensively used in the literatures of Quark-Gluon Plasma (QGP) phenomenology to the large scattering angle regime which may be important in the energy loss of energetic heavy quarks in the deconfined Quark-Gluon Plasma medium. In the proper limits, we reproduce all the relevant existing formulae for the gluon radiation distribution off energetic quarks, heavy or light, used in the QGP phenomenology.

Investigation and applications of a plasma generator

International Nuclear Information System (INIS)

Frere, Isabelle

1992-01-01

This work describes the experimental study of a plasma generator: a cylindrical or parallelepipedic rectangle cathode. A permanent magnet creates an axial magnetic field of a few hundred Gauss. A cold and abnormal glow discharge plasma is obtained. The experimental research on the correlation between the discharge parameters (electrode geometry, gas pressure, discharge voltage and current, magnetic field) of the discharge is presented. Another part of the text mentions some generator applications to surface treatment: evaporation, sputtering, surface modification of polymers by exposure to plasma. (author) [fr

Large Area Sputter Coating on Glass

Science.gov (United States)

Katayama, Yoshihito

Large glass has been used for commercial buildings, housings and vehicles for many years. Glass size for flat displays is getting larger and larger. The glass for the 8th generation is more than 5 m2 in area. Demand of the large glass is increasing not only in these markets but also in a solar cell market growing drastically. Therefore, large area coating is demanded to plus something else on glass more than ever. Sputtering and pyrolysis are the major coating methods on large glass today. Sputtering process is particularly popular because it can deposit a wide variety of materials in good coating uniformity on the glass. This paper describes typical industrial sputtering system and recent progress in sputtering technology. It also shows typical coated glass products in architectural, automotive and display fields and comments on their functions, film stacks and so on.

High-density plasma etching characteristics of indium-gallium-zinc oxide thin films in CF{sub 4}/Ar plasma

Energy Technology Data Exchange (ETDEWEB)

Joo, Young-Hee; Kim, Chang-Il

2015-05-29

We investigated the etching process of indium-gallium-zinc oxide (IGZO) thin films in an inductively coupled plasma system. The dry etching characteristics of the IGZO thin films were studied by varying the CF{sub 4}/Ar gas mixing ratio, RF power, DC-bias voltage, and process pressure. We determined the following optimized process conditions: an RF power of 700 W, a DC-bias voltage of − 150 V, and a process pressure of 2 Pa. A maximum etch rate of 25.63 nm/min for the IGZO thin films was achieved in a plasma with CF{sub 4}/Ar(= 25:75), and the selectivity of IGZO to Al and TiN was found to be 1.3 and 0.7, respectively. We determined the ionic composition of the CF{sub 4}/Ar plasma using optical emission spectroscopy. Analysis of chemical reactions at the IGZO thin film surfaces was performed using X-ray photoelectron spectroscopy. - Highlights: • IGZO thin film was etched by CF{sub 4}/Ar plasma as a function of gas mixing ratio. • IGZO bonds were broken Ar{sup +} sputtering and then reacted with the C-F{sub x} radicals. • The physical sputtering is dominant in etch control compared with chemical etching.

Improvement of the homogeneity of high mobility In{sub 2}O{sub 3}:H films by sputtering through a mesh electrode studied by Monte Carlo simulation and thin film analysis

Energy Technology Data Exchange (ETDEWEB)

Scherg-Kurmes, Harald; Hafez, Ahmad; Szyszka, Bernd [Technische Universitaet Berlin, Einsteinufer 25, 10587, Berlin (Germany); Siemers, Michael; Pflug, Andreas [Fraunhofer IST, Bienroder Weg 54E, 38108, Braunschweig (Germany); Schlatmann, Rutger [Helmholtz Zentrum Berlin, PVcomB, Schwarzschildstr. 3, 12489, Berlin (Germany); Rech, Bernd [Helmholtz Zentrum Berlin, Institute for Silicon Photovoltaics, Kekulestrasse 5, 12489, Berlin (Germany)

2016-09-15

Hydrogen-doped indium oxide (IOH) is a transparent conductive oxide offering great potential to optoelectronic applications because of its high mobility of over 100 cm{sup 2} V{sup -1}s{sup -1}. In films deposited statically by RF magnetron sputtering, a small area directly opposing the target center with a higher resistivity and lower crystallinity than the rest of the film has been found via hall- and XRD-measurements, which we attribute to plasma damage. In order to investigate the distribution of particle energies during the sputtering process we have simulated the RF-sputtering deposition process of IOH by particle-in-cell Monte Carlo (PICMC) simulation. At the surface of ceramic sputtering targets, negatively charged oxygen ions are created. These ions are accelerated toward the substrate in the plasma sheath with energies up to 150 eV. They damage the growing film and reduce its crystallinity. The influence of a negatively biased mesh inside the sputtering chamber on particle energies and distributions has been simulated and investigated. We found that the mesh decreased the high-energetic oxygen ion density at the substrate, thus enabling a more homogeneous IOH film growth. The theoretical results have been verified by XRD X-ray diffractometry (XRD), 4-point probe, and hall measurements of statically deposited IOH films on glass. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Advanced capabilities and applications of a sputter-RBS system

International Nuclear Information System (INIS)

Brijs, B.; Deleu, J.; Beyer, G.; Vandervorst, W.

1999-01-01

In previous experiments, sputter-RBS 1 has proven to be an ideal tool to study the interaction of low energy ions. This contribution employs the same methodology to identify surface contamination induced during sputtering and to the determine absolute sputter yields. In the first experiment ERDA analysis was used to study the evolution of Hydrogen contamination during sputter-RBS experiments. Since the determination of Hydrogen concentration in very thin near surface layers is frequently limited by the presence of a strong surface peak of Hydrogen originating from adsorbed contamination of the residual vacuum, removal of this contamination would increase the sensitivity for Hydrogen detection in the near sub surface drastically. Therefore low energy (12 keV) Argon sputtering was used to remove the Hydrogen surface peak. However enhanced Hydrogen adsorption was observed related to the Ar dose. This experiment shows that severe vacuum conditions and the use of high current densities/sputter yields are a prerequisite for an efficient detection of Hydrogen in the near surface layers. In the second experiment, an attempt was made to determine the sputter yield of Cu during low energy (12 keV) Oxygen bombardment. In order to determine the accumulated dose of the low energy ion beam, a separate Faraday cup in combination with a remote controlled current have been added to the existing sputter-RBS set-up. Alternating sputtering and RBS analysis seem to be an adequate tool for the determination of the absolute sputter yield of Cu and this as well in the as under steady state conditions

Computer simulation of the self-sputtering of uranium

International Nuclear Information System (INIS)

Robinson, M.T.

1983-01-01

The sputtering of polycrystalline α-uranium by uranium ions of energies below 10 keV has been studied in the binary collision approximation using the computer simulation program marlowe. Satisfactory agreement of the computed sputtering yields with the small amount of available experimental data was achieved using the Moliere interatomic potential, a semilocal inelastic loss function, and a planar surface binding barrier, all with conventional parameters. The model is used to discuss low energy sputtering processes and the energy and angular distributions of the reflected primaries and the sputtered target particles

Improvement of NiMoNb to polyimide adhesion by inductively coupled nitrogen plasma treatment

Energy Technology Data Exchange (ETDEWEB)

Bang, S.-H., E-mail: zxclucy@snu.ac.kr

2016-01-01

Graphical abstract: - Highlights: • NiMoNb was introduced as the adhesion layer for flexible Cu-clad laminate structure. • The effect of sputtering and plasma power on the peel strength was studied. • Plasma pretreatment in inductively coupled plasma greatly affects the peel strength. • FCCL with NiMoNb adhesion layer show outstanding peel strength. - Abstract: In this study, the effect of sputtering power on the peel strength of the flexible copper clad laminate (FCCL) was evaluated before and after heat treatment using 180° peel test. An increase in the sputtering powers from 200 W to 600 W increased film density and improved peel strength. To enhance peel strength much more, an inductively coupled plasma (ICP) was treated on the PI surface using N{sub 2} gas with Ar as a function of RF power. A dramatic enhancement of the peel strength, 923 N/m was achieved, especially after heat treatment by changing ICP power from 200 W to 900 W. The reduction ratio of the peel strength for the 900 W plasma-treated FCCL was only 12%, whereas that for the 200 W plasma-treated FCCL was 43%. The root mean square (RMS) surface roughness with PIs exposed to both 200 W and 900 W plasma treatments was rarely changed, while X-ray photoelectron spectroscopy (XPS) showed the substantial increase of C–N functional groups. To obtain insight the film characteristics, the NiMoNb/PI interfaces were investigated by a high resolution transmission electron microscopy (HR-TEM).

Pulsed, Inductively Generated, Streaming Plasma Ion Source for Heavy Ion Fusion Linacs

International Nuclear Information System (INIS)

Steven C. Glidden; Howard D Sanders; John B. Greenly; Daniel L. Dongwoo

2006-01-01

This report describes a compact, high current density, pulsed ion source, based on electrodeless, inductively driven gas breakdown, developed to meet the requirements on normalized emittance, current density, uniformity and pulse duration for an ion injector in a heavy-ion fusion driver. The plasma source produces >10 (micro)s pulse of Argon plasma with ion current densities >100 mA/cm2 at 30 cm from the source and with strongly axially directed ion energy of about 80 eV, and sub-eV transverse temperature. The source has good reproducibility and spatial uniformity. Control of the current density during the pulse has been demonstrated with a novel modulator coil method which allows attenuation of the ion current density without significantly affecting the beam quality. This project was carried out in two phases. Phase 1 used source configurations adapted from light ion sources to demonstrate the feasibility of the concept. In Phase 2 the performance of the source was enhanced and quantified in greater detail, a modulator for controlling the pulse shape was developed, and experiments were conducted with the ions accelerated to >40 kV

Elementary processes in plasma-surface interactions with emphasis on ions

International Nuclear Information System (INIS)

Zalm, P.C.

1985-01-01

Elementary processes occurring at solid surfaces immersed in low pressure plasmas are reviewed. In particular mechanisms leading to anisotropic or directional etching are discussed. The crucial role of ion bombardment is emphasized. First a brief summary of the interaction of (excited) neutrals, ions and electrons with targets is given. Next various aspects of sputter-etching with noble gas and reactive ions are surveyed. Finally it will be argued that synergistic effects, invoked by ion bombardment of a surface under simultaneous exposure to a reactive gas flux, are foremost important in explaining anisotropic plasma etching. It is shown that the role of the ions is not merely to stimulate the chemical reaction path but rather that the active gas flow chemically enhances the sputtering. (author)

Contamination due to memory effects in filtered vacuum arc plasma deposition systems

CERN Document Server

Martins, D R; Verdonck, P; Brown, I G

2002-01-01

Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

Contamination due to memory effects in filtered vacuum arc plasma deposition systems

International Nuclear Information System (INIS)

Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.

2002-01-01

Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the stopping and range of ions in matter code. We find film contamination of the order of 10 -4 -10 -3 , and the memory of the prior history of the deposition hardware can be relatively long lasting

Contamination due to memory effects in filtered vacuum arc plasma deposition systems

Energy Technology Data Exchange (ETDEWEB)

Martins, D.R.; Salvadori, M.C.; Verdonck, P.; Brown, I.G.

2002-08-13

Thin film synthesis by filtered vacuum arc plasma deposition is a widely used technique with a number of important emerging technological applications. A characteristic feature of the method is that during the deposition process not only is the substrate coated by the plasma, but the plasma gun itself and the magnetic field coil and/or vacuum vessel section constituting the macroparticle filter are also coated to some extent. If then the plasma gun cathode is changed to a new element, there can be a contamination of the subsequent film deposition by sputtering from various parts of the system of the previous coating species. We have experimentally explored this effect and compared our results with theoretical estimates of sputtering from the SRIM (Stopping and Range of Ions in Matter) code. We find film contamination of order 10-4 - 10-3, and the memory of the prior history of the deposition hardware can be relatively long-lasting.

Characteristics of ITO films with oxygen plasma treatment for thin film solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Park, Yong Seob [Department of Photoelectronics Information, Chosun College of Science and Technology, Gwangju (Korea, Republic of); Kim, Eungkwon [Digital Broadcasting Examination, Korean Intellectual Property Office, Daejeon, Suwon 440-746 (Korea, Republic of); Hong, Byungyou [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong, 300, Jangan-gu, Suwon 440-746 (Korea, Republic of); Lee, Jaehyoeng, E-mail: jaehyeong@skku.edu [School of Electronic and Electrical Engineering, Sungkyunkwan University, Cheoncheon-dong, 300, Jangan-gu, Suwon 440-746 (Korea, Republic of)

2013-12-15

Graphical abstract: The effect of O{sub 2} plasma treatment on the surface and the work function of ITO films. - Highlights: • ITO films were prepared on the glass substrate by RF magnetron sputtering method. • Effects of O{sub 2} plasma treatment on the properties of ITO films were investigated. • The work function of ITO film was changed from 4.67 to 5.66 eV by plasma treatment. - Abstract: The influence of oxygen plasma treatment on the electro-optical and structural properties of indium-tin-oxide films deposited by radio frequency magnetron sputtering method were investigated. The films were exposed at different O{sub 2} plasma powers and for various durations by using the plasma enhanced chemical vapor deposition (PECVD) system. The resistivity of the ITO films was almost constant, regardless of the plasma treatment conditions. Although the optical transmittance of ITO films was little changed by the plasma power, the prolonged treatment slightly increased the transmittance. The work function of ITO film was changed from 4.67 eV to 5.66 eV at the plasma treatment conditions of 300 W and 60 min.

Bulk plasma properties in the pulsed glow discharge

International Nuclear Information System (INIS)

Jackson, Glen P.; King, Fred L.

2003-01-01

This work focuses on the spatial and temporal characteristics of a glow discharge plasma operated with power pulses of 5 ms in duration at 25% duty cycle. Interpretation of emission data provides insight into the nature of the plasma at each instant of a typical pulse cycle and at each position in space. Because the bulk plasma properties affect the distribution of excited energy levels of the sputtered atoms, an improved understanding of the plasma affords the ability to select conditions that enhance analytically important emission lines. Optical emission spectroscopy was used to determine the relative populations of excited states for atoms and ions during the initial breakdown, the steady state and the recombining periods of the discharge pulse cycle. The plasma is highly ionizing in nature at the time of breakdown--with lower excited states being overpopulated--before reaching the steady state, or plateau, period, also ionizing in nature. These behaviors arise from a loss of charged particles and photons to the surroundings that shifts the plasma away from Saha and Boltzmann balances during these periods. The post-pulse period typically displays recombining behavior, characterized by population inversion for selected species--except for regions close to the cathode, where electrons and ions are lost by diffusion and are not available for recombination. The sputtered analyte atom emissions closely mimic those of the plasma bath gas, except that their emissions persevere for longer in the recombining after-peak period than do the discharge gas species

Matted-fiber divertor tagets for sputter resistance

International Nuclear Information System (INIS)

Gierszewski, P.J.; Todreas, N.E.; Mikic, B.; Yang, T.F.

1981-06-01

Reductions in net sputtering yields can be obtained by altering the surface topography to maximize redeposition of sputtered atoms. A simple analysis is used to indicate a potential reduction by a factor of 2 to 5 for matted fiber divertor targets, relatively independent of incident, reflected and sputtered atom distributions. The fiber temperature is also shown to be acceptable, even up to 10 MW/m 2 , for reasonably combinations of materials, fiber diameter and fiber spacing

Pfirsch–Schlüter neoclassical heavy impurity transport in a rotating plasma

International Nuclear Information System (INIS)

Belli, E A; Candy, J; Angioni, C

2014-01-01

In this work, we extend previous analytic theories for the neoclassical transport of a trace heavy impurity in a rotating plasma in the Pfirsch–Schlüter regime. The complete diffusive and convective components of the ambipolar particle flux are derived. The solution is valid for arbitrary impurity charge and impurity Mach number and for general geometry. Inclusion of finite main-ion temperature gradient effects is shown in the small ion Mach number limit. A simple interpolation formula is derived for the case of high impurity charge and circular geometry. While an enhancement of the diffusion coefficient is found for order one impurity Mach number, a reduction due to the rotation-driven poloidal asymmetry in the density occurs for very large Mach number. (paper)

A hybrid heterojunction with reverse rectifying characteristics fabricated by magnetron sputtered TiOx and plasma polymerized aniline structure

International Nuclear Information System (INIS)

Sarma, Bimal K; Pal, Arup R; Bailung, Heremba; Chutia, Joyanti

2012-01-01

A TiO x film produced by direct current reactive magnetron sputtering without substrate heating or post-deposition annealing and a plasma polymerized aniline (PPA) structure deposited in the same reactor by a radio-frequency glow discharge without the assistance of a carrier gas are used for the fabrication of a heterojunction. The gas phase discharge is investigated by a Langmuir probe and optical emission spectroscopy. The individual layers and the heterojunction are characterized for structural and optoelectronic properties. PPA has polymer-like structure and texture and is characterized by saturated-unsaturated, branched and crosslinked networks. X-ray photoelectron spectroscopy reveals a slightly reduced TiO x surface, which exhibits near band edge luminescence. The free radicals trapped in PPA readily react with oxygen when exposed to atmosphere. The heterojunction shows reverse rectifying characteristics under dark and ultraviolet (UV) irradiation. The energy levels of TiO x and PPA might exhibit reverse band bending and electrons and holes are accumulated on both sides of the heterojunction. The charge accumulation phenomena at the interface may play a key role in the device performance of a hybrid heterojunction. The current-voltage characteristic of the heterojunction is sensitive to UV light, so the structure may be used for photo-sensing applications. (paper)

In-situ optical emission spectroscopy for a better control of hybrid sputtering/evaporation process for the deposition of Cu(In,Ga)Se{sub 2} layers

Energy Technology Data Exchange (ETDEWEB)

Posada, Jorge; Jubault, Marie [Institute of Research and Development on Photovoltaic Energy (IRDEP), EDF-CNRS-Chimie ParisTech, UMR 7174, 6 Quai Watier, 78401 Chatou (France); Bousquet, Angélique; Tomasella, Eric [Clermont Université, Université Blaise Pascal, Institute of Chemistry of Clermont-Ferrand (ICCF), CNRS-UMR 6296, 24 Avenue des Landais, 63171 Aubière (France); Lincot, Daniel [Institute of Research and Development on Photovoltaic Energy (IRDEP), EDF-CNRS-Chimie ParisTech, UMR 7174, 6 Quai Watier, 78401 Chatou (France)

2015-05-01

In this work, we have developed a hybrid one-step co-sputtering/evaporation Cu(In,Ga)Se{sub 2} (CIGS) process, where Cu, In and Ga are sputtered simultaneously with the thermal evaporation of selenium, thus avoiding the H{sub 2}Se use. An appropriate control of the selenium flux is very important to prevent the target poisoning and hence some material flux variations. Indeed, the control of the CIGS composition must be rigorous to ensure reproducible solar cell properties. In this regard, a study of the correlations between plasma species and thin film composition, structure and morphology has been performed by varying power values and Se evaporation temperature in the 170 to 230 °C range. We started by studying the plasma with a powerful technique: optical emission spectroscopy, following light emissions from different plasma species: sputtered Cu, Ga, In but also evaporated Se. Hence, we determined the Se flow threshold avoiding target poisoning and the main parameter controlling the CIGS composition. Obviously, we also focused our interest on the material. We measured film composition and thickness of the samples with X-ray fluorescence and by energy dispersive X-ray. Different phases formed during the process were identified by Raman spectroscopy and X-ray diffraction. The optoelectronic cell properties showed promising efficiency of 10.3% for an absorber with composition ratios of [Cu]/([In] + [Ga]) = 1.02 and [Ga]/([In] + [Ga]) = 0.44. Finally, this work shows that we are able to control this hybrid process and thus the structure and composition of CIGS thin film for industrial transfer in the photovoltaic field. - Highlights: • We have developed a hybrid one-step co-sputtering/evaporation Cu(In,Ga)Se{sub 2} process. • Correlations between plasma species and thin film composition have been performed. • We determined the Se flow threshold avoiding target poisoning. • Efficient small-area CIGS cells with 10.3% efficiency were fabricated.

Sputtering of a silicon surface: Preferential sputtering of surface impurities

Czech Academy of Sciences Publication Activity Database

Nietiadi, M.L.; Rosandi, Y.; Lorinčík, Jan; Urbassek, H.M.

-, č. 303 (2013), s. 205-208 ISSN 0168-583X Institutional support: RVO:67985882 Keywords : Sputtering * Molecular dynamics * SIMS Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.186, year: 2013

Laboratory simulation of erosion by space plasma

International Nuclear Information System (INIS)

Kristoferson, L.; Fredga, K.

1976-04-01

A laboratory experiment has been made where a plasma stream collides with targets made of different materials of cosmic interest. The experiment can be viewed as a process simulation of the solar wind particle interaction with solid surfaces in space, e.g. cometary dust. Special interest is given to sputtering of OH and Na. It is shown that the erosion of solid particles in interplanetary space at large heliocentric distances is most likely dominated by sputtering and by sublimation near the sun. The heliocentric distance of the limit between the two regions is determined mainly by the material properties of the eroded surface, e.g. heat of sublimation and sputtering yield, a typical distance being 0,5 a.u. It is concluded that the observations of Na in comets at large solar distances, in some cases also near the sun, is most likely to be explained by solar wind sputtering. OH emission in space could be of importance also from 'dry', water-free, matter by means of molecule sputtering. The observed OH production rates in comets are however too large to be explained in this way and are certainly the results of sublimation and dissociation of H 2 O from an icy nucleus. (Auth.)

Vehicle exhaust gas clearance by low temperature plasma-driven nano-titanium dioxide film prepared by radiofrequency magnetron sputtering.

Directory of Open Access Journals (Sweden)

Shuang Yu

Full Text Available A novel plasma-driven catalysis (PDC reactor with special structure was proposed to remove vehicle exhaust gas. The PDC reactor which consisted of three quartz tubes and two copper electrodes was a coaxial dielectric barrier discharge (DBD reactor. The inner and outer electrodes firmly surrounded the outer surface of the corresponding dielectric barrier layer in a spiral way, respectively. Nano-titanium dioxide (TiO2 film prepared by radiofrequency (RF magnetron sputtering was coated on the outer wall of the middle quartz tube, separating the catalyst from the high voltage electrode. The spiral electrodes were designed to avoid overheating of microdischarges inside the PDC reactor. Continuous operation tests indicated that stable performance without deterioration of catalytic activity could last for more than 25 h. To verify the effectiveness of the PDC reactor, a non-thermal plasma(NTP reactor was employed, which has the same structure as the PDC reactor but without the catalyst. The real vehicle exhaust gas was introduced into the PDC reactor and NTP reactor, respectively. After the treatment, compared with the result from NTP, the concentration of HC in the vehicle exhaust gas treated by PDC reactor reduced far more obviously while that of NO decreased only a little. Moreover, this result was explained through optical emission spectrum. The O emission lines can be observed between 870 nm and 960 nm for wavelength in PDC reactor. Together with previous studies, it could be hypothesized that O derived from catalytically O3 destruction by catalyst might make a significant contribution to the much higher HC removal efficiency by PDC reactor. A series of complex chemical reactions caused by the multi-components mixture in real vehicle exhaust reduced NO removal efficiency. A controllable system with a real-time feedback module for the PDC reactor was proposed to further improve the ability of removing real vehicle exhaust gas.

Physics of ion sputtering

International Nuclear Information System (INIS)

Robinson, M.T.

1984-04-01

The ejection of atoms by the ion bombardment of solids is discussed in terms of linear collision cascade theory. A simple argument describes the energies of the ejecta, but elaborate models are required to obtain accurate sputtering yields and related quantities. These include transport theoretical models based on linearized Boltzmann equations, computer simulation models based on the binary collision approximation, and classical many-body dynamical models. The role of each kind of model is discussed. Several aspects of sputtering are illustrated by results from the simulation code MARLOWE. 20 references, 6 figures

Anodic self-organized transparent nanotubular/porous hematite films from Fe thin-films sputtered on FTO and photoelectrochemical water splitting

Czech Academy of Sciences Publication Activity Database

Wang, L.; Lee, C.-Y.; Kirchgeorg, R.; Liu, N.; Lee, K.; Kment, Š.; Hubička, Zdeněk; Krýsa, J.; Olejníček, J.; Čada, M.; Zbořil, R.; Schmuki, P.

2015-01-01

Roč. 41, č. 12 (2015), s. 9333-9341 ISSN 0922-6168. [Pannonian Symposium on Catalysis /12./. Třešť, 16.09.2014-20.09.2014] Institutional support: RVO:68378271 Keywords : hematite * nanotubular * anodization * magnetron * sputtering * water splitting Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.833, year: 2015

Morphology and structure evolution of Cu(In,Ga)S{sub 2} films deposited by reactive magnetron co-sputtering with electron cyclotron resonance plasma assistance

Energy Technology Data Exchange (ETDEWEB)

Nie, Man, E-mail: man.nie@helmholtz-berlin.de; Ellmer, Klaus [Department of Solar Fuels and Energy Storage Materials, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, D14109 Berlin (Germany)

2014-02-28

Cu(In,Ga)S{sub 2} (CIGS) films were deposited on Mo coated soda lime glass substrates using an electron cyclotron resonance plasma enhanced one-step reactive magnetron co-sputtering process (ECR-RMS). The crystalline quality and the morphology of the Cu(In,Ga)S{sub 2} films were investigated by X-ray diffraction, atomic force microscopy, scanning electron microscopy, and X-ray fluorescence. We also compared these CIGS films with films previously prepared without ECR assistance and find that the crystallinity of the CIGS films is correlated with the roughness evolution during deposition. Atomic force microscopy was used to measure the surface topography and to derive one-dimensional power spectral densities (1DPSD). All 1DPSD spectra of CIGS films exhibit no characteristic peak which is typical for the scaling of a self-affine surface. The growth exponent β, characterizing the roughness R{sub q} evolution during the film growth as R{sub q} ∼ d{sup β}, changes with film thickness. The root-mean-square roughness at low temperatures increases only slightly with a growth exponent β = 0.013 in the initial growth stage, while R{sub q} increases with a much higher exponent β = 0.584 when the film thickness is larger than about 270 nm. Additionally, we found that the H{sub 2}S content of the sputtering atmosphere and the Cu- to-(In + Ga) ratio has a strong influence of the morphology of the CIGS films in this one-step ECR-RMS process.

The Analysis of Distribution of Thickness of ThinFilm Coating During the Magnetron Sputtering on Systems with Planetary Movement of Substrate

Directory of Open Access Journals (Sweden)

H. R. Sagatelyan

2014-01-01

Full Text Available The article subject is a thin-film coating process using ion-plasma sputter deposition systems with magnetron sputtering targets. To improve coating thickness evenness of parts various manufacturers equip their systems with mechanisms for moving the coating parts, and sometimes the magnetrons. More specifically, the article concerns the ion-plasma sputtering process using a system equipped with a mechanism for providing a planetary movement of the coating parts in the plane perpendicular to the planes of two sputtering targets.The purpose of this work was to improve a distribution of the coating thickness evenness on the sputtering surface of the part. It is achieved through selection of the best combinations of kinematic and geometric factors that characterize a particular sputtering operation, depending on the size and position of the surface to be coated. These factors include a ratio between directions and frequencies of the self-rotation of satellite planetary gear, which holds a work piecesubstrate, and the translational motion i.e. planetary carrier rotation to carry the satellite; the angles of planes of the right and left magnetrons with respect to the system frontal plane. Since there is, essentially, a lack of mathematical models to perform the appropriate calculations for the considered type of system designs, a more specific aim of the article is to develop a technique to evaluate the uneven thickness of coatings provided by the systems of this type.To achieve this more specific purpose the analytical technique had been used, applying the postulates of analytical geometry and theoretical mechanics. The main results of the research described in the article are as follows:- mathematical models of dependencies of geometric and kinematic parameters, changing during the sputtering process and characterizing each considered point on the surface of the work piece, on the current position of the work piece in the structure of the planetary

Influence of Microwave Power on the Properties of Hydrogenated Diamond-Like Carbon Films Prepared by ECR Plasma Enhanced DC Magnetron Sputtering

International Nuclear Information System (INIS)

Ru Lili; Huang Jianjun; Gao Liang; Qi Bing

2010-01-01

Electron cyclotron resonance (ECR) plasma was applied to enhance the direct current magnetron sputtering to prepare hydrogenated diamond-like carbon (H-DLC) films. For different microwave powers, both argon and hydrogen gas are introduced separately as the ECR working gas to investigate the influence of microwave power on the microstructure and electrical property of the H-DLC films deposited on P-type silicon substrates. A series of characterization methods including the Raman spectrum and atomic force microscopy are used. Results show that, within a certain range, the increase in microwave power affects the properties of the thin films, namely the sp 3 ratio, the hardness, the nanoparticle size and the resistivity all increase while the roughness decreases with the increase in microwave power. The maximum of resistivity amounts to 1.1 x 10 9 Ω · cm. At the same time it is found that the influence of microwave power on the properties of H-DLC films is more pronounced when argon gas is applied as the ECR working gas, compared to hydrogen gas.

Electronic sputtering of large organic molecules and its application in bio molecular mass spectrometry

International Nuclear Information System (INIS)

Sundqvist, B.U.R.

1992-01-01

This is a review of research which has its origin in the discovery of Plasma Desorption Mass Spectrometry (PDMS). Two main fields of research have developed, namely fundamental studies of the ejection process at fast ion impact and studies of applications of the new mass spectrometric technique. In this review the emphasis will be on the process of electronic sputtering of organic solids but also applications of this process in bio molecular mass spectrometry will be discussed. (author)

Self-sputtering runaway in high power impulse magnetron sputtering: The role of secondary electrons and multiply charged metal ions

International Nuclear Information System (INIS)

Anders, Andre

2008-01-01

Self-sputtering runaway in high power impulse magnetron sputtering is closely related to the appearance of multiply charged ions. This conclusion is based on the properties of potential emission of secondary electrons and energy balance considerations. The effect is especially strong for materials whose sputtering yield is marginally greater than unity. The absolute deposition rate increases ∼Q 1/2 , whereas the rate normalized to the average power decreases ∼Q -1/2 , with Q being the mean ion charge state number

Deposition of polymer films in low pressure reactive plasmas

Energy Technology Data Exchange (ETDEWEB)

Biederman, H.

1981-12-11

Sputtering and plasma polymerization have found wide application as deposition techniques and have been extensively studied. R.f. sputtering of plastics, in particular of polytetrafluoroethylene, are discussed in the first part of this paper. In the second part, the general concept of plasma polymerization is considered and some examples of applications of plasma-polymerized films are presented. Special attention is paid to fluorocarbon and fluorochlorocarbon films. It has been suggested that these films could be used in thin film capacitors or as passivating layers for integrated circuits. In the optical field some of these films have been used as convenient moisture-resistant, protective and antireflecting coatings. Their mechanical properties have also been examined with the intention of using them for reducing surface friction. More recently some metals have been incorporated into fluorocarbon films to obtain layers with novel properties. Experiments in which films were prepared by the plasma polymerization of certain Freons are described. Some electrical and optical properties of these films are presented. High dielectric losses were obtained in a metal/film/metal sandwich configuration and the possible influence of ambient atmospheric effects on these measurements is discussed.

Sensitivity and stability of sputtered sandwich photocells

International Nuclear Information System (INIS)

Murray, H.; Piel, A.

1979-01-01

The physical parameters of sputtered Metal-Semiconductor-Metal photocells are described in view of solar energy conversion. Specific properties of sputtered films lead to a particular stability of physical parameters such as dark conduction, capacitance and dielectric losses. Interband transitions occur when the photon energy is larger than the bandgap of the photoconductor. The transport of photo-excited carriers in the built-in electric field involves the existence of a photovoltaic effect. The influence of sputtering on the specific properties of solar energy conversion is discussed. (author)

Characterization of atomic oxygen from an ECR plasma source

International Nuclear Information System (INIS)

Naddaf, M; Bhoraskar, V N; Mandale, A B; Sainkar, S R; Bhoraskar, S V

2002-01-01

A low-power microwave-assisted electron cyclotron resonance (ECR) plasma system is shown to be a powerful and effective source of atomic oxygen (AO) useful in material processing. A 2.45 GHz microwave source with maximum power of 600 W was launched into the cavity to generate the ECR plasma. A catalytic nickel probe was used to determine the density of AO. The density of AO is studied as a function of pressure and axial position of the probe in the plasma chamber. It was found to vary from ∼1x10 20 to ∼10x10 20 atom m -3 as the plasma pressure was varied from 0.8 to 10 mTorr. The effect of AO in oxidation of silver is investigated by gravimetric analysis. The stoichiometric properties of the oxide are studied using the x-ray photoelectron spectroscopy as well as energy dispersive x-ray analysis. The degradation of the silver surface due to sputtering effect was viewed by scanning electron spectroscopy. The sputtering yield of oxygen ions in the plasma is calculated using the TRIM code. The effects of plasma pressure and the distance from the ECR zone on the AO density were also investigated. The density of AO measured by oxidation of silver is in good agreement with results obtained from the catalytic nickel probe

Characterization of atomic oxygen from an ECR plasma source

Science.gov (United States)

Naddaf, M.; Bhoraskar, V. N.; Mandale, A. B.; Sainkar, S. R.; Bhoraskar, S. V.

2002-11-01

A low-power microwave-assisted electron cyclotron resonance (ECR) plasma system is shown to be a powerful and effective source of atomic oxygen (AO) useful in material processing. A 2.45 GHz microwave source with maximum power of 600 W was launched into the cavity to generate the ECR plasma. A catalytic nickel probe was used to determine the density of AO. The density of AO is studied as a function of pressure and axial position of the probe in the plasma chamber. It was found to vary from ~1×1020 to ~10×1020 atom m-3 as the plasma pressure was varied from 0.8 to 10 mTorr. The effect of AO in oxidation of silver is investigated by gravimetric analysis. The stoichiometric properties of the oxide are studied using the x-ray photoelectron spectroscopy as well as energy dispersive x-ray analysis. The degradation of the silver surface due to sputtering effect was viewed by scanning electron spectroscopy. The sputtering yield of oxygen ions in the plasma is calculated using the TRIM code. The effects of plasma pressure and the distance from the ECR zone on the AO density were also investigated. The density of AO measured by oxidation of silver is in good agreement with results obtained from the catalytic nickel probe.

Characterization of atomic oxygen from an ECR plasma source

Energy Technology Data Exchange (ETDEWEB)

Naddaf, M [Center for Advanced Studies in Material Science and Solid State Physics, University of Pune, Pune 411 007 (India); Bhoraskar, V N [Center for Advanced Studies in Material Science and Solid State Physics, University of Pune, Pune 411 007 (India); Mandale, A B [National Chemical Laboratory, Pashan, Pune 411008 (India); Sainkar, S R [National Chemical Laboratory, Pashan, Pune 411008 (India); Bhoraskar, S V [Center for Advanced Studies in Material Science and Solid State Physics, University of Pune, Pune 411 007 (India)

2002-11-01

A low-power microwave-assisted electron cyclotron resonance (ECR) plasma system is shown to be a powerful and effective source of atomic oxygen (AO) useful in material processing. A 2.45 GHz microwave source with maximum power of 600 W was launched into the cavity to generate the ECR plasma. A catalytic nickel probe was used to determine the density of AO. The density of AO is studied as a function of pressure and axial position of the probe in the plasma chamber. It was found to vary from {approx}1x10{sup 20} to {approx}10x10{sup 20} atom m{sup -3} as the plasma pressure was varied from 0.8 to 10 mTorr. The effect of AO in oxidation of silver is investigated by gravimetric analysis. The stoichiometric properties of the oxide are studied using the x-ray photoelectron spectroscopy as well as energy dispersive x-ray analysis. The degradation of the silver surface due to sputtering effect was viewed by scanning electron spectroscopy. The sputtering yield of oxygen ions in the plasma is calculated using the TRIM code. The effects of plasma pressure and the distance from the ECR zone on the AO density were also investigated. The density of AO measured by oxidation of silver is in good agreement with results obtained from the catalytic nickel probe.

Heavy Flavor Physics in Heavy-Ion Collisions with STAR Heavy Flavor Tracker

International Nuclear Information System (INIS)

Yifei Zhang

2010-01-01

Heavy quarks are a unique tool to probe the strongly interacting matter created in relativistic heavy-ion collisions at RHIC energies. Due to their large mass, energetic heavy quarks are predicted to lose less energy than light quarks by gluon radiation when they traverse a Quark-Gluon Plasma. In contrast, recent measurements of non-photonic electrons from heavy quark decays at high transverse momentum (p T ) show a jet quenching level similar to that of the light hadrons. Heavy quark are produced mainly at early stage in heavy-ion collisions, thus they are proposed to probe the QCD medium and to be sensitive to bulk medium properties. Ultimately, their flow behavior may help establish whether light quarks thermalize. But due to the absence of the measurement of B-mesons and precise measurement of D-mesons, it is difficult to separate bottom and charm contributions experimentally in current non-photonic electron measurements for both spectra and elliptic flow v 2 . Therefore, topological reconstruction of D-mesons and identification of electrons from charm and bottom decays are crucial to understand the heavy flavor production and their in medium properties. The Heavy Flavor Tracker (HFT) is a micro-vertex detector utilizing active pixel sensors and silicon strip technology. The HFT will significantly extend the physics reach of the STAR experiment for precise measurement of charmed and bottom hadrons. We present a study on the open charm nuclear modification factor, elliptic flow v 2 and λ c measurement as well as the measurement of bottom mesons via a semi-leptonic decay. (author)

Methods for natural gas and heavy hydrocarbon co-conversion

Science.gov (United States)

Kong, Peter C [Idaho Falls, ID; Nelson, Lee O [Idaho Falls, ID; Detering, Brent A [Idaho Falls, ID

2009-02-24

A reactor for reactive co-conversion of heavy hydrocarbons and hydrocarbon gases and includes a dielectric barrier discharge plasma cell having a pair of electrodes separated by a dielectric material and passageway therebetween. An inlet is provided for feeding heavy hydrocarbons and other reactive materials to the passageway of the discharge plasma cell, and an outlet is provided for discharging reaction products from the reactor. A packed bed catalyst may optionally be used in the reactor to increase efficiency of conversion. The reactor can be modified to allow use of a variety of light sources for providing ultraviolet light within the discharge plasma cell. Methods for upgrading heavy hydrocarbons are also disclosed.

High dose, heavy ion implantation into metals: the use of sacrificial surface layers to enhance retention

International Nuclear Information System (INIS)

Clapham, L.

1994-01-01

While of considerable interest for the production of metallic alloys, high dose, heavy ion implantation is highly problematical, since the process is limited by sputtering effects. Sputtering is less significant, however, for light target materials, such as C and Al. This paper summarizes studies involving the use of light materials (such as C and Al) which act as slowly sputtering ''sacrificial layers'' when deposited on metallic targets prior to heavy ion implantation. The use of C and Al sacrificial coatings has enabled implanted ion retentions of 100% to be obtained in a number of ion-metal target systems, where the retentions in uncoated samples were as low as 20%. Ion implantation invariably leads to mixing at the sacrificial layer-metal target interface. This mixing may be detrimental in certain systems, so it is useful to be able to minimize or remove this mixed region. To achieve this, a number of techniques have been investigated: (1) removal of the mixed region in the latter stages of the implant; (2) using a barrier layer or chemical effects to minimize mixing at the sacrificial layer-metal interface; (3) choosing a sacrificial layer material which forms a mixed region which has desirable properties. The results of these investigations, for a number of different ion-target systems, are outlined in this paper. (orig.)

Modelling of the reactive sputtering process with non-uniform discharge current density and different temperature conditions

International Nuclear Information System (INIS)

Vasina, P; Hytkova, T; Elias, M

2009-01-01

The majority of current models of the reactive magnetron sputtering assume a uniform shape of the discharge current density and the same temperature near the target and the substrate. However, in the real experimental set-up, the presence of the magnetic field causes high density plasma to form in front of the cathode in the shape of a toroid. Consequently, the discharge current density is laterally non-uniform. In addition to this, the heating of the background gas by sputtered particles, which is usually referred to as the gas rarefaction, plays an important role. This paper presents an extended model of the reactive magnetron sputtering that assumes the non-uniform discharge current density and which accommodates the gas rarefaction effect. It is devoted mainly to the study of the behaviour of the reactive sputtering rather that to the prediction of the coating properties. Outputs of this model are compared with those that assume uniform discharge current density and uniform temperature profile in the deposition chamber. Particular attention is paid to the modelling of the radial variation of the target composition near transitions from the metallic to the compound mode and vice versa. A study of the target utilization in the metallic and compound mode is performed for two different discharge current density profiles corresponding to typical two pole and multipole magnetics available on the market now. Different shapes of the discharge current density were tested. Finally, hysteresis curves are plotted for various temperature conditions in the reactor.

Basic atomic interactions of accelerated heavy ions in matter atomic interactions of heavy ions

CERN Document Server

Tolstikhina, Inga; Winckler, Nicolas; Shevelko, Viacheslav

2018-01-01

This book provides an overview of the recent experimental and theoretical results on interactions of heavy ions with gaseous, solid and plasma targets from the perspective of atomic physics. The topics discussed comprise stopping power, multiple-electron loss and capture processes, equilibrium and non-equilibrium charge-state fractions in penetration of fast ion beams through matter including relativistic domain. It also addresses mean charge-states and equilibrium target thickness in ion-beam penetrations, isotope effects in low-energy electron capture, lifetimes of heavy ion beams, semi-empirical formulae for effective cross sections. The book is intended for researchers and graduate students working in atomic, plasma and accelerator physics.

Hydrogen superpermeable membrane operation under plasma conditions

International Nuclear Information System (INIS)

Bacal, M.; Bruneteau, A.M.; Livshits, A.I.; Alimov, V.N.; Notkin, M.E.

2003-01-01

The effect of ion bombardment on hydrogen plasma-driven permeation through a superpermeable niobium membrane was investigated. It was found that the increase of membrane temperature and the doping of membrane material with oxygen results in the decrease of ion bombardment effect and in permeability increase. It was demonstrated that membrane decarbonization leads to the formation of a membrane state resistant to sputtering. Possible applications of the membrane resistant to ion bombardment as plasma facing components are considered

Effects of heavy ion temperature on low-frequency kinetic Alfven waves

International Nuclear Information System (INIS)

Yang, L.; Wu, D. J.

2011-01-01

Heavy ion-electron (or proton) temperature ratio varies in a wide range in the solar and space environment. In this paper, proton and heavy ion temperatures are included in a three-fluid plasma model. For the specified parameters, low-frequency (<< heavy ion gyrofrequency) kinetic Alfven waves (KAWs) with sub- and super-Alfvenic speeds are found to coexist in the same plasma environment. Our results show that the temperature ratio of heavy ions to electrons can considerably affect the dispersion, propagation, and electromagnetic polarizations of the KAWs. In particular, the temperature ratio can increase the ratio of parallel to perpendicular electric fields and the normalized electric to magnetic field ratio, the variations of which are greatly different in regions with a high heavy ion temperature and with a low one. The results may help to understand the physical mechanism of some energization processes of heavy ions in the solar and space plasma environment. Effects of the ratio of electron thermal to Alfven speeds and the heavy ion abundance on these parameters are also discussed.

Sputtering of two-phase AgxCuγ alloys

International Nuclear Information System (INIS)

Bibic, N.; Milosavljevic, M.; Perusko, D.; Wilson, I.H.

1992-01-01

Elemental sputtering yields from two phase AgCu alloys were measured for 20, 40 and 50 at % Ag. Argon ion bombardment energies were in the range 35-55 keV and the ion dose was 1 x 10 19 ions cm -2 . The sputtering yield for silver was found to be considerably below what was expected by simple selective sputtering of a two component alloy. Analysis by electron probe X-ray microanalysis and scanning electron microscopy of the eroded surface indicated that surface diffusion of copper from copper rich grains and geometrical constraints in the dense cone forest on Cu/Ag eutectic regions combine to reduce the sputtering yield for silver. (author)

Impurity radiation from a beam-plasma neutron source

International Nuclear Information System (INIS)

Molvik, A.W.

1995-01-01

Impurity radiation, in a worst case evaluation for a beam-plasma neutron source (BPNS), does not limit performance. Impurities originate from four sources: (a) sputtering from walls by charge exchange or alpha particle bombardment, (b) sputtering from limiters, (c) plasma desorption of gas from walls and (d) injection with neutral beams. Sources (c) and (d) are negligible; adsorbed gas on the walls of the confinement chamber and the neutral beam sources is removed by the steady state discharge. Source (b) is negligible for impinging ion energies below the sputtering threshold (T i ≤ 0.025 keV on tungsten) and for power densities to the limiter within the capabilities of water cooling (30-40 MW/m 2 ); both conditions can be satisfied in the BPNS. Source (a) radiates 0.025 MW/m 2 to the neutron irradiation samples, compared with 5 to 10 MW/m 2 of neutrons; and radiates a total of 0.08 MW from the plasma column, compared with 60 MW of injected power. The particle bombardment that yields source (a) deposits an average of 2.7 MW/m 2 on the samples, within the capabilities of helium gas cooling (10 MW/m 2 ). An additional worst case for source (d) is evaluated for present day 2 to 5 s pulsed neutral beams with 0.1% impurity density and is benchmarked against 2XIIB. The total radiation would increase a factor of 1.5 to ≤ 0.12 MW, supporting the conclusion that impurities will not have a significant impact on a BPN. (author). 61 refs, 7 figs, 2 tabs

Low-damage high-throughput grazing-angle sputter deposition on graphene

Energy Technology Data Exchange (ETDEWEB)

Chen, C.-T.; Gajek, M.; Raoux, S. [IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Casu, E. A. [IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Politecnico di Torino, Turin 10129 (Italy)

2013-07-15

Despite the prevalence of sputter deposition in the microelectronics industry, it has seen very limited applications for graphene electronics. In this letter, we report systematic investigation of the sputtering induced damages in graphene and identify the energetic sputtering gas neutrals as the primary cause of graphene disorder. We further demonstrate a grazing-incidence sputtering configuration that strongly suppresses fast neutral bombardment and retains graphene structure integrity, creating considerably lower damage than electron-beam evaporation. Such sputtering technique yields fully covered, smooth thin dielectric films, highlighting its potential for contact metals, gate oxides, and tunnel barriers fabrication in graphene device applications.

Low-damage high-throughput grazing-angle sputter deposition on graphene

International Nuclear Information System (INIS)

Chen, C.-T.; Gajek, M.; Raoux, S.; Casu, E. A.

2013-01-01

Despite the prevalence of sputter deposition in the microelectronics industry, it has seen very limited applications for graphene electronics. In this letter, we report systematic investigation of the sputtering induced damages in graphene and identify the energetic sputtering gas neutrals as the primary cause of graphene disorder. We further demonstrate a grazing-incidence sputtering configuration that strongly suppresses fast neutral bombardment and retains graphene structure integrity, creating considerably lower damage than electron-beam evaporation. Such sputtering technique yields fully covered, smooth thin dielectric films, highlighting its potential for contact metals, gate oxides, and tunnel barriers fabrication in graphene device applications

Low-damage high-throughput grazing-angle sputter deposition on graphene

Science.gov (United States)

Chen, C.-T.; Casu, E. A.; Gajek, M.; Raoux, S.

2013-07-01

Despite the prevalence of sputter deposition in the microelectronics industry, it has seen very limited applications for graphene electronics. In this letter, we report systematic investigation of the sputtering induced damages in graphene and identify the energetic sputtering gas neutrals as the primary cause of graphene disorder. We further demonstrate a grazing-incidence sputtering configuration that strongly suppresses fast neutral bombardment and retains graphene structure integrity, creating considerably lower damage than electron-beam evaporation. Such sputtering technique yields fully covered, smooth thin dielectric films, highlighting its potential for contact metals, gate oxides, and tunnel barriers fabrication in graphene device applications.

Influence of surface topography on the sputtering yields of silver

International Nuclear Information System (INIS)

Pan Jisheng; Wang Zhenxia; Tao Zhenlan; Zhang Jiping

1992-01-01

The sputtering yields of silver have been measured as a function of the fluence of incident Ar + ions (27 keV) using the collector technique and RBS analysis. The irradiated surface was examined by scanning electron microscopy (SEM). It is shown that the sputtering yields of surfaces with topography are enhanced relative to smooth surfaces of silver, but the extent of the enhancement depends on the irradiation dose. The experimental results can be explained assuming that the surface topography and sputtering yield are a function of incident angle. It is obvious that the surface topography is an important factor to influence the sputtering yield. The term ''apparent sputtering yield'' has specifically been used when referring to the experimental sputtering yield of a surface with topography, to emphasize the difference with a smooth surface. (orig.)

Jet-Underlying Event Separation Method for Heavy Ion Collisions at the Relativistic Heavy Ion Collider

OpenAIRE

Hanks, J. A.; Sickles, A. M.; Cole, B. A.; Franz, A.; McCumber, M. P.; Morrison, D. P.; Nagle, J. L.; Pinkenburg, C. H.; Sahlmueller, B.; Steinberg, P.; von Steinkirch, M.; Stone, M.

2012-01-01

Reconstructed jets in heavy ion collisions are a crucial tool for understanding the quark-gluon plasma. The separation of jets from the underlying event is necessary particularly in central heavy ion reactions in order to quantify medium modifications of the parton shower and the response of the surrounding medium itself. There have been many methods proposed and implemented for studying the underlying event substructure in proton-proton and heavy ion collisions. In this paper, we detail a me...

Development of intense pulsed heavy ion beam diode using gas puff plasma gun as ion source

International Nuclear Information System (INIS)

Ito, H.; Higashiyama, M.; Takata, S.; Kitamura, I.; Masugata, K.

2006-01-01

A magnetically insulated ion diode with an active ion source of a gas puff plasma gun has been developed in order to generate a high-intensity pulsed heavy ion beam for the implantation process of semiconductors and the surface modification of materials. The nitrogen plasma produced by the plasma gun is injected into the acceleration gap of the diode with the external magnetic field system. The ion diode is operated at diode voltage approx. =200 kV, diode current approx. =2 kA and pulse duration approx. =150 ns. A new acceleration gap configuration for focusing ion beam has been designed in order to enhance the ion current density. The experimental results show that the ion current density is enhanced by a factor of 2 and the ion beam has the ion current density of 27 A/cm 2 . In addition, the coaxial type Marx generator with voltage 200 kV and current 15 kA has been developed and installed in the focus type ion diode. The ion beam of ion current density approx. =54 A/cm 2 is obtained. To produce metallic ion beams, an ion source by aluminum wire discharge has been developed and the aluminum plasma of ion current density ∼70 A/cm 2 is measured. (author)

Reactive physical vapor deposition of TixAlyN: Integrated plasma-surface modeling characterization

International Nuclear Information System (INIS)

Zhang Da; Schaeffer, J.K.

2004-01-01

Reactive physical vapor deposition (RPVD) has been widely applied in the microelectronic industry for producing thin films. Fundamental understanding of RPVD mechanisms is needed for successful process development due to the high sensitivity of film properties on process conditions. An integrated plasma equipment-target nitridation modeling infrastructure for RPVD has therefore been developed to provide mechanistic insights and assist optimal process design. The target nitridation model computes target nitride coverage based on self-consistently derived plasma characteristics from the plasma equipment model; target sputter yields needed in the plasma equipment model are also self-consistently derived taking into account the yield-suppressing effect from nitridation. The integrated modeling infrastructure has been applied to investigating RPVD processing with a Ti 0.8 Al 0.2 compound target and an Ar/N 2 gas supply. It has been found that the process produces athermal metal neutrals as the primary deposition precursor. The metal stoichiometry in the deposited film is close to the target composition due to the predominance of athermal species in the flux that reaches the substrate. Correlations between process parameters (N 2 flow, target power), plasma characteristics, surface conditions, and deposition kinetics have been studied with the model. The deposition process is characterized by two regimes when the N 2 flow rate is varied. When N 2 is dilute relative to argon, target nitride coverage increases rapidly with increasing N 2 flow. The sputter yield and deposition rate consequently decrease. For less dilute N 2 mixtures, the sputter yield and deposition rate are stable due to the saturation of target nitridation. With increasing target power, the electron density increases nearly linearly while the variation of N generation is much smaller. Target nitridation and its suppression of the sputter yield saturate at high N 2 flow rendering these parameters

Electron cyclotron resonance hydrogen/helium plasma characterization and simulation of pumping in tokamaks

International Nuclear Information System (INIS)

Outten, C.A.

1992-01-01

Electron Cyclotron Resonance (ECR) plasmas have been employed to simulate the plasma conditions at the edge of a tokamak in order to investigate hydrogen/helium uptake in thin metal films. The process of microwave power absorption, important to characterizing the ECR plasma source, was investigated by measuring the electron density and temperature with a Langmuir probe and optical spectroscopy as a function of the magnetic field gradient and incident microwave power. A novel diagnostic, carbon resistance probe, provided a direct measure of the ion energy and fluence while measurements from a Langmuir probe were used for comparison. The Langmuir probe gave a plasma potential minus floating potential of 30 ± 5 eV, in good agreement with the carbon resistance probe result of ion energy ≤ 40 eV. The measured ion energy was consistent with the ion energy predicted from a model based upon divergent magnetic field extraction. Also, based upon physical sputtering of the carbon, the hydrogen fluence rate was determined to be 1 x 10 16 /cm 2 -sec for 50 Watts of incident microwave power. ECR hydrogen/helium plasmas were used to study preferential pumping of helium in candidate materials for tokamak pump-limiters: nickel, vanadium, aluminum, and nickel/aluminum multi-layers. Nickel and vanadium exhibited similar pumping capacities whereas aluminum showed a reduced capacity due to increased sputtering. A helium retention model based upon ion implantation ranges and sputtering rates agreed with the experimental data. A new multilayer/bilayer pumping concept showed improved pumping above that for single element films

Experimental studies of lithium-based surface chemistry for fusion plasma-facing materials applications

International Nuclear Information System (INIS)

Allain, J.P.; Rokusek, D.L.; Harilal, S.S.; Nieto-Perez, M.; Skinner, C.H.; Kugel, H.W.; Heim, B.; Kaita, R.; Majeski, R.

2009-01-01

Lithium has enhanced the operational performance of fusion devices such as: TFTR, CDX-U, FTU, T-11 M, and NSTX. Lithium in the solid and liquid state has been studied extensively in laboratory experiments including its erosion and hydrogen-retaining properties. Reductions in physical sputtering up to 40-60% have been measured for deuterated solid and liquid lithium surfaces. Computational modeling indicates that up to a 1:1 deuterium volumetric retention in lithium is possible. This paper presents the results of systematic in situ laboratory experimental studies on the surface chemistry evolution of ATJ graphite under lithium deposition. Results are compared to post-mortem analysis of similar lithium surface coatings on graphite exposed to deuterium discharge plasmas in NSTX. Lithium coatings on plasma-facing components in NSTX have shown substantial reduction of hydrogenic recycling. Questions remain on the role lithium surface chemistry on a graphite substrate has on particle sputtering (physical and chemical) as well as hydrogen isotope recycling. This is particularly due to the lack of in situ measurements of plasma-surface interactions in tokamaks such as NSTX. Results suggest that the lithium bonding state on ATJ graphite is lithium peroxide and with sufficient exposure to ambient air conditions, lithium carbonate is generated. Correlation between both results is used to assess the role of lithium chemistry on the state of lithium bonding and implications on hydrogen pumping and lithium sputtering. In addition, reduction of factors between 10 and 30 reduction in physical sputtering from lithiated graphite compared to pure lithium or carbon is also measured.

Fuzzy tungsten in a magnetron sputtering device

Energy Technology Data Exchange (ETDEWEB)

Petty, T.J., E-mail: tjpetty@liv.ac.uk [Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ (United Kingdom); Khan, A. [Pariser Building-G11, School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, M13 9PL (United Kingdom); Heil, T. [NiCaL, Block C Waterhouse Building, 1-3 Brownlow Street, Liverpool, L69 3GL (United Kingdom); Bradley, J.W., E-mail: j.w.bradley@liverpool.ac.uk [Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ (United Kingdom)

2016-11-15

Helium ion induced tungsten nanostructure (tungsten fuzz) has been studied in a magnetron sputtering device. Three parameters were varied, the fluence from 3.4 × 10{sup 23}–3.0 × 10{sup 24} m{sup −2}, the He ion energy from 25 to 70 eV, and the surface temperature from 900 to 1200 K. For each sample, SEM images were captured, and measurements of the fuzz layer thickness, surface roughness, reflectivity, and average structure widths are provided. A cross-over point from pre-fuzz to fully formed fuzz is found at 2.4 ± 0.4 × 10{sup 24} m{sup −2}, and a temperature of 1080 ± 60 K. No significant change was observed in the energy sweep. The fuzz is compared to low fluence fuzz created in the PISCES-A linear plasma device. Magnetron fuzz is less uniform than fuzz created by PISCES-A and with generally larger structure widths. The thicknesses of the magnetron samples follow the original Φ{sup 1/2} relation as opposed to the incubation fluence fit. - Highlights: • Fuzz has been created in a magnetron sputtering device. • Three parameters for fuzz formation have been swept. • A cross-over from pre-fuzz to fully formed fuzz is seen. • Evidence for annealing out at lower temperatures than has been seen before. • Evidence to suggest that fuzz grown in discrete exposures is not consistent with fuzz grown in one long exposure.

Fuzzy tungsten in a magnetron sputtering device

International Nuclear Information System (INIS)

Petty, T.J.; Khan, A.; Heil, T.; Bradley, J.W.

2016-01-01

Helium ion induced tungsten nanostructure (tungsten fuzz) has been studied in a magnetron sputtering device. Three parameters were varied, the fluence from 3.4 × 10 23 –3.0 × 10 24  m −2 , the He ion energy from 25 to 70 eV, and the surface temperature from 900 to 1200 K. For each sample, SEM images were captured, and measurements of the fuzz layer thickness, surface roughness, reflectivity, and average structure widths are provided. A cross-over point from pre-fuzz to fully formed fuzz is found at 2.4 ± 0.4 × 10 24  m −2 , and a temperature of 1080 ± 60 K. No significant change was observed in the energy sweep. The fuzz is compared to low fluence fuzz created in the PISCES-A linear plasma device. Magnetron fuzz is less uniform than fuzz created by PISCES-A and with generally larger structure widths. The thicknesses of the magnetron samples follow the original Φ 1/2 relation as opposed to the incubation fluence fit. - Highlights: • Fuzz has been created in a magnetron sputtering device. • Three parameters for fuzz formation have been swept. • A cross-over from pre-fuzz to fully formed fuzz is seen. • Evidence for annealing out at lower temperatures than has been seen before. • Evidence to suggest that fuzz grown in discrete exposures is not consistent with fuzz grown in one long exposure.

Global modelling of plasma-wall interaction in reversed field pinches

Science.gov (United States)

Bagatin, M.; Costa, S.; Ortolani, S.

1989-04-01

The impurity production and deuterium recycling mechanisms in ETA—BETA II and RFX are firstly discussed by means of a simple model applicable to a stationary plasma interacting with the wall. This gives the time constant and the saturation values of the impurity concentration as a function of the boundary temperature and density. If the latter is sufficiently high, the impurity buildup in the main plasma becomes to some extent stabilized by the shielding effect of the edge. A self-consistent global model of the time evolution of an RFP plasma interacting with the wall is then described. The bulk and edge parameters are derived by solving the energy and particle balance equations incorporating some of the basic plasma-surface processes, such as sputtering, backscattering and desorption. The application of the model to ETA-BETA II confirms the impurity concentrations of the light and metal impurities as well as the time evolution of the average electron density found experimentally under different conditions. The model is then applied to RFX, a larger RFP experiment under construction, whose wall will be protected by a full graphite armour. The time evolution of the discharge shows that carbon sputtering could increase Zeff to ~ 4, but without affecting significantly the plasma performance.

Global modelling of plasma-wall interaction in reversed field pinches

International Nuclear Information System (INIS)

Bagatin, M.; Costa, S.; Ortolani, S.

1989-01-01

The impurity production and deuterium recycling mechanisms in ETA-BETA II and RFX are firstly discussed by means of a simple model applicable to a stationary plasma interacting with the wall. This gives the time constant and the saturation values of the impurity concentration as a function of the boundary temperature and density. If the latter is sufficiently high, the impurity buildup in the main plasma becomes to some extent stabilized by the shielding effect of the edge. A self-consistent global model of the time evolution of an RFP plasma interacting with the wall is then described. The bulk and edge parameters are derived by solving the energy and particle balance equations incorporating some of the basic plasma-surface processes, such as sputtering, backscattering and desorption. The application of the model to ETA-BETA II confirms the impurity concentrations of the light and metal impurities as well as the time evolution of the average electron density found experimentally under different conditions. The model is then applied to RFX, a larger RFP experiment under construction, whose wall will be protected by a full graphite armour. The time evolution of the discharge shows that carbon sputtering could increase Z eff to ≅ 4, but without affecting significantly the plasma performance. (orig.)

Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy,and Related Fields

International Nuclear Information System (INIS)

Grisham, L.R.; Kwan, J.W.

2008-01-01

Some years ago it was suggested that halogen negative ions could offer a feasible alternative path to positive ions as a heavy ion fusion driver beam which would not suffer degradation due to electron accumulation in the accelerator and beam transport system, and which could be converted to a neutral beam by photodetachment near the chamber entrance if desired. Since then, experiments have demonstrated that negative halogen beams can be extracted and accelerated away from the gas plume near the source with a surviving current density close to what could be achieved with a positive ion of similar mass, and with comparable optical quality. In demonstrating the feasibility of halogen negative ions as heavy ion driver beams, ion - ion plasmas, an interesting and somewhat novel state of matter, were produced. These plasmas, produced near the extractor plane of the sources, appear, based upon many lines of experimental evidence, to consist of almost equal densities of positive and negative chlorine ions, with only a small component of free electrons. Serendipitously, the need to extract beams from this plasma for driver development provides a unique diagnostic tool to investigate the plasma, since each component - positive ions, negative ions, and electrons - can be extracted and measured separately. We discuss the relevance of these observations to understanding negative ion beam extraction from electronegative plasmas such as halogens, or the more familiar hydrogen of magnetic fusion ion sources. We suggest a concept which might improve negative hydrogen extraction by the addition of a halogen. The possibility and challenges of producing ion - ion plasmas with thin targets of halogens or, perhaps, salt, is briefly addressed.

Perspective on the Role of Negative Ions and Ion-Ion Plasmas in Heavy Ion Fusion Science, Magnetic Fusion Energy, and Related Fields

International Nuclear Information System (INIS)

Grisham, L.R.; Kwan, J.W.

2008-01-01

Some years ago it was suggested that halogen negative ions (1)could offer a feasible alternative path to positive ions as a heavy ion fusion driver beam which would not suffer degradation due to electron accumulation in the accelerator and beam transport system, and which could be converted to a neutral beam by photodetachment near the chamber entrance if desired. Since then, experiments have demonstrated that negative halogen beams can be extracted and accelerated away from the gas plume near the source with a surviving current density close to what could be achieved with a positive ion of similar mass, and with comparable optical quality. In demonstrating the feasibility of halogen negative ions as heavy ion driver beams, ion-ion plasmas, an interesting and somewhat novel state of matter, were produced. These plasmas, produced near the extractor plane of the sources, appear, based upon many lines of experimental evidence, to consist of almost equal densities of positive and negative chlorine ions, with only a small component of free electrons. Serendipitously, the need to extract beams from this plasma for driver development provides a unique diagnostic tool to investigate the plasma, since each component--positive ions, negative ions, and electrons--can be extracted and measured separately. We discuss the relevance of these observations to understanding negative ion beam extraction from electronegative plasmas such as halogens, or the more familiar hydrogen of magnetic fusion ion sources. We suggest a concept which might improve negative hydrogen extraction by the addition of a halogen. The possibility and challenges of producing ion-ion plasmas with thin targets of halogens or, perhaps, salt, is briefly addressed

Titanium oxidation by rf inductively coupled plasma

International Nuclear Information System (INIS)

Valencia-Alvarado, R; López-Callejas, R; Barocio, S R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Rodríguez-Méndez, B G; De la Piedad-Beneitez, A; De la Rosa-Vázquez, J M

2014-01-01

The development of titanium dioxide (TiO 2 ) films in the rutile and anatase phases is reported. The films have been obtained from an implantation/diffusion and sputtering process of commercially pure titanium targets, carried out in up to 500 W plasmas. The experimental outcome is of particular interest, in the case of anatase, for atmospheric pollution degradation by photocatalysis and, as to the rutile phase, for the production of biomaterials required by prosthesis and implants. The reactor employed consists in a cylindrical pyrex-like glass vessel inductively coupled to a 13.56 MHz RF source. The process takes place at a 5×10 −2 mbar pressure with the target samples being biased from 0 to -3000 V DC. The anatase phase films were obtained from sputtering the titanium targets over glass and silicon electrically floated substrates placed 2 cm away from the target. The rutile phase was obtained by implantation/diffusion on targets at about 700 °C. The plasma was developed from a 4:1 argon/oxygen mixture for ∼5 hour processing periods. The target temperature was controlled by means of the bias voltage and the plasma source power. The obtained anatase phases did not require annealing after the plasma oxidation process. The characterization of the film samples was conducted by means of x-ray diffraction, scanning electron microscopy, x-ray photoelectron spectroscopy and Raman spectroscopy

Rhodium coated mirrors deposited by magnetron sputtering for fusion applications

International Nuclear Information System (INIS)

Marot, L.; De Temmerman, G.; Oelhafen, P.; Covarel, G.; Litnovsky, A.

2007-01-01

Metallic mirrors will be essential components of all optical spectroscopy and imaging systems for ITER plasma diagnostics. Any change in the mirror performance, in particular, its reflectivity, due to erosion of the surface by charge exchange neutrals or deposition of impurities will influence the quality and reliability of the detected signals. Due to its high reflectivity in the visible wavelength range and its low sputtering yield, rhodium appears as an attractive material for first mirrors in ITER. However, the very high price of the raw material calls for using it in the form of a film deposited onto metallic substrates. The development of a reliable technique for the preparation of high reflectivity rhodium films is therefore of the highest importance. Rhodium layers with thicknesses of up to 2 μm were produced on different substrates of interest (Mo, stainless steel, Cu) by magnetron sputtering. Produced films exhibit a low roughness and crystallite size of about 10 nm with a dense columnar structure. No impurities were detected on the surface after deposition. Scratch tests demonstrate that adhesion properties increase with substrate hardness. Detailed optical characterizations of Rh-coated mirrors as well as results of erosion tests performed both under laboratory conditions and in the TEXTOR tokamak are presented in this paper

Rhodium-coated mirrors deposited by magnetron sputtering for fusion applications

International Nuclear Information System (INIS)

Marot, L.; Temmermann, G. de; Oelhafen, P.; Mathys, D.; Covarel, G.; Litnovsky, A.

2007-01-01

Metallic mirrors will be essential components of all optical spectroscopy and imaging systems for plasma diagnostics that will be used in ITER. Any change in the mirror performance, in particular its reflectivity, will influence the quality and reliability of detected signals. Due to its high reflectivity in the visible wavelength range and its low sputtering yield, rhodium may be a good candidate material for first mirrors in ITER. However, the very high price of the raw material calls for using it in the form of a film deposited onto metallic substrates. The development of a reliable technique for the preparation of high reflectivity rhodium films is therefore of the highest importance. Rhodium layers with thicknesses of up to 2 μm were produced on different relevant substrates (Mo, Stainless Steel, Cu) by magnetron sputtering. Produced films exhibit a low roughness, crystallite size of about 10 nm with a dense columnar structure. No impurities were detected on the surface after deposition. Scratch test results demonstrate that adhesion properties increase with the substrate hardness. The detailed optical characterizations of Rh coated mirrors as well as the results of erosion tests performed both under laboratory conditions and in TEXTOR will be presented in this paper. (orig.)

Ga lithography in sputtered niobium for superconductive micro and nanowires

International Nuclear Information System (INIS)

Henry, M. David; Wolfley, Steve; Monson, Todd; Lewis, Rupert

2014-01-01

This work demonstrates the use of focused ion beam (FIB) implanted Ga as a lithographic mask for plasma etching of Nb films. Using a highly collimated Ga beam of a FIB, Nb is implanted 12 nm deep with a 14 nm thick Ga layer providing etch selectivity better than 15:1 with fluorine based etch chemistry. Implanted square test patterns, both 10 μm by 10 μm and 100 μm by 100 μm, demonstrate that doses above than 7.5 × 10 15  cm −2 at 30 kV provide adequate mask protection for a 205 nm thick, sputtered Nb film. The resolution of this dry lithographic technique is demonstrated by fabrication of nanowires 75 nm wide by 10 μm long connected to 50 μm wide contact pads. The residual resistance ratio of patterned Nb films was 3. The superconducting transition temperature (T c ) = 7.7 K was measured using a magnetic properties measurement system. This nanoscale, dry lithographic technique was extended to sputtered TiN and Ta here and could be used on other fluorine etched superconductors such as NbN, NbSi, and NbTi.

Effects of ion sputtering on semiconductor surfaces

International Nuclear Information System (INIS)

McGuire, G.E.

1978-01-01

Ion beam sputtering has been combined with Auger spectroscopy to study the effects of ion beams on semiconductor surfaces. Observations on the mass dependence of ion selective sputtering of two component systems are presented. The effects of ion implantation are explained in terms of atomic dilution. Experimental data are presented that illustrate the super-position of selective sputtering and implantation effects on the surface composition. Sample reduction from electron and ion beam interaction is illustrated. Apparent sample changes which one might observe from the effects of residual gas contamination and electric fields are also discussed. (Auth.)

Investigation of supercapacitors with carbon electrodes obtained from argon-acetylene arc plasma

OpenAIRE

Kavaliauskas, Žydrūnas

2010-01-01

The dissertation examines topics related to the formation of supercapacitors using plasma technology and their analysis. Plasma spray technology was used to form supercapacitors electrodes. Carbon was deposited on stainless steel surface using the atmospheric pressure argon-acetylene plasma. The deposition of nickel oxide on the surface of carbon electrodes was made using magnetron sputtering method. The influence of acetylene amount to the supercapacitors electrodes and the electrical charac...

Model of the macrostructure formation of plasma sprayed coatings

International Nuclear Information System (INIS)

Gnedovets, A.G.; Kalita, V.I.

2007-01-01

A 3D discrete ballistic model of plasma sprayed coatings structure formation is presented. The effect of a spraying angle on porous macrostructure of coatings is investigated by numerical computations.Computer simulation results as well as experimental data show that at a sputtering angle less than 45 deg the mechanism of surface relief formation is changed and the relief consists of valleys and ridges under such conditions of plasma spraying [ru

Laser sputter neutral mass spectrometry