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In the contribution there is presented a new computer modelling technique, which can be used in multidimensional computer simulations of plasma at low pressure. The technique is based on the fluid–particle approach and can be used in the study of the range of physical phenomena, e.g. plasma behaviour in the vicinity of substrates, probe diagnostics, plasma technology, etc. The computer model is useable...
Non-equilibrium plasmas can be generated by atmospheric pressure glow discharges, amongst others by atmospheric pressure plasma jets (APPJ), which feature a capacitive radio-frequency discharge between bare metallic electrodes.We investigated the stability conditions for discharges in an APPJ operated with helium–argon mixtures. Uniform α-discharges can be sustained in mixtures ranging from pure helium...
To understand the various effects induced by the ion bombardment one needs to know the sputtering yields for the sputtering conditions applied. Experimental data are rare however, and the reliability of the calculated values should be checked. Thus the measurement of sputtering yield is important. Recently, we have published a work where we have applied AES depth profiling to determine the relative...
Several techniques of computational physics used in low-temperature plasma simulations at higher pressures are presented in our contribution. The first approach is called fluid modelling, the second one hybrid modelling and the third technique—particle modelling presented here is realized as a part of hybrid model. There are several techniques applicable in computational plasma physics but some of...
The GaAs/AlGaAs heterostructure layer system grown by MBE on GaAs substrate was designed to be used for micro-mechanical structure fabrication. In the first step, double-side aligned photolithography is carried out to define the etching masks on both sides of the substrate. After this, highly selective reactive ion etching (SRIE) of GaAs from the front side is used to determine the lateral dimensions...
Continuous oscillations of the pressure of hydrogen and some other gases were observed in an ultra high vacuum (UHV) apparatus. The oscillations arose progressively during experiments with hydrogen permeation through stainless-steel ion-implanted samples, later they occurred in the apparatus without any sample as well. They were observed for a long time, detected with an ionisation gauge and a mass...
Thin silicon films were deposited by the plasma-enhanced chemical vapor deposition using standard 13.6MHz radiofrequency gas discharge in silane diluted by hydrogen. The deposition conditions were kept constant for all samples, with the exception of only one parameter: the degree of dilution was varied from low values that produce amorphous layers up to the high dilution that resulted in a high degree...
In this paper, we report on a novel Nb-Ti/Al/Ni/Au metallic system proposed to form ohmic contact to AlGaN/GaN heterostructure. The metallic system uses deposition of thin niobium layer as the first layer in contact with the AlGaN barrier layer before deposition of the conventional Ti/Al/Ni/Au metallic system. The fabrication and electrical characterization of the Nb-Ti/Al/Ni/Au based ohmic contacts...
A study on oxygen plasma functionalization of polyethyleneterephthalate (PET) is presented. Samples were exposed to a weakly ionized, highly dissociated RF oxygen plasma with an electron temperature of 5eV, a density of positive ions of 8×10 15 m −3 and a density of neutral oxygen atoms of 4×10 21 m −3 . The oxygen pressure was 75Pa and the discharge power was 200W...
The local elemental composition and morphology of stainless steel surfaces before and after high-temperature bake out (vacuum firing) has been investigated by atom probe (AP) and scanning tunnelling microscopy (STM). The AP depth profiling analysis show significant surface enrichment of nickel after vacuum firing. The surface of AISI 304L stainless steel sheet samples imaged by STM show a significant...
Carbon–titanium nanocomposite thin films were deposited by DC magnetron sputtering on oxidized silicon substrates in argon. The films were prepared at different deposition temperatures between 25 and 800°C. Transmission electron microscopy was used to determine the structure of the films. All the C–Ti nanocomposites consisted of columnar TiC structure with average column width ∼10 and 20nm and a thin...
Superhard titanium diboride (TiB 2 ) coatings (H v > 40GPa) were deposited in Ar atmosphere from stoichiometric TiB 2 target using an unbalanced direct current (d. c.) magnetron. Polished Si (001), stainless steel, high-speed steel (HSS) and tungsten carbide (WC) substrates were used for deposition. The influence of negative substrate bias, U s , and substrate temperature,...
SiO x C y H z thin films were deposited from hexamethyldisiloxane (HMDSO)/O 2 mixtures in a parallel plate, capacitively coupled, RF plasma reactor. Polyethylene terephthalate (PET), Si(100) wafers and KBr tablets were chosen as substrates. Effect of HMDSO/O 2 ratio, total treatment pressure and power input on the properties of the deposited films were investigated...
Amorphous silicon materials and its alloys became extensively used in some technical applications involving large area of the microelectronic and optoelectronic devices. However, the amorphous-crystalline transition, segregation and diffusion processes still have numerous unanswered questions. In this work we study the Sb diffusion into an amorphous Si film by means of Secondary Neutral Mass Spectrometry...
W x C y thin films with different compositions were studied in order to correlate their properties with the thin-film composition and chemical bonding of C and W atoms. Three W x C y thin films with C concentrations in the range 40–80at% were deposited on WC–Co substrates by the plasma beam sputtering technique. The composition of the thin films and chemical states...
Nanocrystalline materials are of high interest, because mechanical and physical properties of such materials are different from those or coarse-grained type. Continuous and smooth nanocrystalline diamond (NCD) thin films were successfully grown on mirror polished silicon substrates, using double bias plasma-enhanced hot filament chemical vapour deposition technique. A gas mixture of Ar:CH 4 ...
The main objective of the present study was identification of the electronic states associated with W ions and defects (oxygen vacancies), which determine the surface stoichiometry of WO 3 thin films and consequently their reactivity. The electronic surface structure of WO 3 thin films was deduced from electron energy loss spectroscopy (EELS) analyses. We have investigated the changes...
Complex metallic alloys (CMAs) are a group of materials that have a giant unit cell and a high density of point defects. Among the more interesting phases is the hexagonal Al 4 Cr, containing 574 atoms, which can also be alloyed with iron to form a ternary Al 4 (Cr,Fe). One possibility to deposit such thin films is by sequential deposition of constituent elements and subsequent heat...
Auger electron spectroscopy (AES) depth profiling was used to study the oxidation phenomena of AISI316L stainless steel during treatment with oxygen plasma. Samples were exposed to low-pressure RF plasma with a high dissociation degree, so that the flux of oxygen atoms onto the sample surface exceeded 10 24 m −2 s −1 . A set of samples was oxidized 4min at different temperatures...
Optical emission spectroscopy was applied for the characterization of inductively coupled RF oxygen plasma at pressures between 10 and 300Pa. The plasma was generated with an RF generator at a frequency of 27.12MHz and output power of 300W. Spectra were measured in the range 200–1100nm by an optical spectrometer. At high pressure, the main spectral features observed were the wavelengths of the atomic...
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