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In this contribution, the results achieved by the optical characterization of diamond-like carbon (DLC) films are presented. A multi-sample modification of variable angle of incidence spectroscopic ellipsometry (VASE) is used to determine the values of the thicknesses and spectral dependences of the optical constants of these films. It is shown that this optical method is very suitable for characterizing...
At pressures higher than approximately 5 mbar it is nowadays common practice to use a two-stage pressure reduction set-up, consisting of a capillary tube as a first pressure reduction stage and an orifice as a second pressure reduction stage. We have recently demonstrated, that by using a specially constructed helium flushed probe system, a quick transport of species extracted from a process gas to...
In this paper, integration of spectroscopic ellipsometry in a vertical furnace for measurement and control during chemical vapour deposition and thermal oxidation is presented. The major goal of this activity was to adapt the ellipsometer arrangement to the furnace geometry with a minimum impact on the furnace process performance. Modifications in the furnace geometry were restricted as far as possible,...
Multi-source vacuum deposition processes allow manufacture of composite materials which are impossible to produce by conventional techniques. The condensation mechanisms of physical vapour deposition (PVD) may also favour the formation of new material structures which are not known from techniques such as, e.g., solidification from the melt. This paper summarizes the influence of different deposition...
We have implemented a gas-phase chemistry numerical simulation of a typical radio frequency, low-pressure plasma. We have applied it to the study of CH 4 /Ar plasmas used for the deposition of diamond and diamond-like carbon films. Our results show that CH 3 is the most abundant carbon-containing radical in pure methane discharges and in CH 4 /Ar mixtures at low argon concentrations,...
One of the research directions of the ATOMKI-ECRIS is the systematic investigation of the confined plasma. In our laboratory we have the instrumentation background for two plasma research methods: X-ray and visible light diagnostics is possible outside the plasma chamber and the plasma can be investigated directly by movable Langmuir probes. Recently, a new research direction was started in order...
The electrical and optical properties of polycrystalline silicon films are dominated by grain-boundary defects. It is therefore of particular interest to obtain columnar grain growth during the deposition process. In this work, we studied the properties of RTCVD deposited polycrystalline silicon films suitable for solar cell production. The effect of substrate temperature on texture and paramagnetically...
Compositionally modulated amorphous Si-Ge thin films with repeat lengths between 2.5 and 9nm have been prepared using magnetron sputtering. The interdiffusion coefficient (D) was determined from the change in the small angle X-ray diffraction satellite (SAXRD) intensities. Experimental results confirm the theoretically predicted strong concentration dependence of the interdiffusion coefficient. It...
Two different approaches for the HFET's T-shaped gate fabrication are presented. Besides the conventional approach based on the three-layer resist structure a new one based on the poly Si/polyimide bilayer is demonstrated using which a ratio of the gate head length to the gate foot length larger than 10 is achieved. Both of the fabrication techniques presented seem to be very promising for nanometer...
Niobium (Nb) thin films were grown on (111) and (100) surfaces of Cu single-crystals using a special Nb evaporation source. The quality of the substrate surface and epitaxial parameters of the Nb over-layers were examined by reflection high energy electron diffraction. Two types of Nb deposit structure have been found and are dependent on the substrate temperature during the deposition. At room substrate...
At metal-semiconductor interfaces, the Fermi level is usually found ''pinned'' in the bandgap. Schottky barriers of Ag/n-Si structures deposited by the ionized cluster beam (ICB) technique show a similar Fermi level pinning behaviour with respect to the metal atom acceleration voltage. We propose a simple model for the density of interface states at the disordered interface in an ICB Schottky structure...
Residual stresses in films produced by physical vapour deposition (PVD) techniques result from the contribution of thermal, intrinsic and extrinsic stresses. Tensile intrinsic stresses are usually observed in not fully dense films deposited by thermal evaporation from non-energetic particles. Compressive intrinsic stresses develop in relatively dense films deposited at low temperatures under energetic...
Recently, a model was proposed to explain the non-linearity of the V-I characteristics of the reactive magnetron discharge with a Ti-cathode in an Ar-N 2 gas mixture. It accounts for the rapid development of an additional (lower impedance) metal-target discharge, which is coupled in parallel to the existent one, after outrunning a current threshold. Here, we employed various surface science...
The oxidation of hydrogen at the interface between different metallic (Ni, Pt, Ag and Au) point contact electrodes and the proton conductor Sr 0.995 Ce 0.95 Y 0.05 O 2.970 (SCY) at temperatures of 600-800 o C was investigated by impedance spectroscopy in atmospheres containing from 1 to 9%...
In this work, properties of TiZrV getter films prepared on stainless-steel substrates by magnetron sputtering were investigated. Changes of sample surface during thermal activation and interaction of the activated getter with CO were studied by means of XPS and ESD of neutrals. The XPS measurements reflect the disappearance of the superficial oxide layer coveing air-exposed TiZrV surfaces and the...
Capacitance-voltage measurements and deep-level transient spectroscopy have shown that RF hydrogen plasma treatment of thin (13nm) SiO 2 /p-Si structures at 20, 100 and 300 o C generates defects in the oxide, at the SiO 2 /Si interface and in the near-surface region of Si substrate. The density of these defects depends on the substrate temperature during plasma exposure. The...
Silicon nitride and silicon oxynitride dielectric layers were fabricated by reactive RF sputtering from an Si target in conventional equipment. Sputtering was done using a gas mixture of high-purity nitrogen and oxygen at a total pressure of 2-3Pa. To investigate the sputtering process parameters silicon nitride was deposited on polished slices of Si. Multiple angle incidence ellipsometry was applied...
We have investigated the plasma chemistry of process gases consisting of hydrogen with a small admixture of chlorinated methanes in a pulsed r.f. discharge. The temporal development of certain species in the plasma was explored by experiment and simulation. Experiment and simulation are in good agreement and show a very fast decomposition of the chlorinated methanes to the main stable species hydrogen...
We evaluate the lifetimes of the surface and the first image state of the (111) surface of gold, the image state having the peculiarity of being a resonant state. The self-energy of the excited quasiparticle is calculated within the GW approximation. A one-dimensional potential is used to obtain the single-particle wave functions by solving the Schrodinger equation. The screened Coulomb interaction...
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