Vacuum
An optical technique is proposed to determine the surface roughness and grain diameter for films having columnar grains and deposited onto nonabsorbing substrates.
Titanium nitride films were prepared on glass substrates by dc reactive magnetron sputtering from a titanium metal target in an Ar+N 2 mixed atmosphere. During deposition, the total pressure was varied from 2 10 - 3 to 3 10 - 2 mbar. The effects of the total pressure on the structural, optical and electrical properties of the films were studied using X-ray diffraction,...
The spectroscopic and Langmuir probe characteristics of a low pressure argon glow discharge plasma were studied and the electron temperature (T e ) was measured independently by both methods. The experiments were carried out in a SS 304 uhv chamber used for studying glow discharge cleaning techniques. Two types of excitation sources, dc and rf, were used. The Corona model was used to evaluate...
A saddle field cold cathode source was used to produce diamond-like carbon (DLC) coatings on glass substrates by dissociation and ionisation of acetylene in a low pressure vacuum. Langmuir probe investigations of the ion current density and plasma potentials showed the existence of a positive potential barrier at a distance of 100 mm from the source with an ionisation degree of up to 80% in the carbon...
A comprehensive description of the broadening of the absorption tail in polycrystalline semiconductor films has been presented by considering intrinsic inhomogeneity due to random distribution of grains and grain boundary regions and the fluctuation in potential from local thermal vibrations present at the grains and grain-grain interfaces. The model has been applied to describe the absorption data...
We have investigated isotope effects in the sputtering of a u 6 3 Cu 6 9 . 1 6 5 Cu 3 0 . 9 mixture under 2 keV Xe ion bombardment, using a dynamic Monte Carlo program. For the u- 6 3 Cu- 6 5 Cu sputtering, our calculations show that the isotope fractionation difference between small and large polar angles, δ(15 ...
During titanium layer deposition with a hollow cathode arc discharge, the integral energy influx to the substrate has been monitored by measuring temperature gradients. Discharge power and substrate voltage have been varied. Simultaneously, the plasma parameters in front of the substrate were determined by means of Langmuir-probe measurements and energy resolved mass spectrometry (plasma monitoring)...
1 6 O ions at 75 MeV incident energy have been used to study the irradiation effects on the normal state resistance variation with fluence. The studies conducted include the measurement of resistance variation with dose due to the ion used. The samples were the bulk sintered pellets of YBa 2 Cu 3 O 7 - x maintained at normal temperature (T 300 K) and low...
A new ultrahigh vacuum (uhv) scanning funneling microscope (STM) with exchangeable samples and tips is constructed which is compatible with typical surface science techniques. The STM incorporates a number of novel features, including an optimized inner vibration isolation system. A tip-to-sample approach is performed by means of a simple, reliable all-mechanical system with only two parts moving...
Film thickness distribution in a so called symmetrical magnet magnetron sputtering system was simulated according to the model T = ∫ 0 2 π ∫ 0 R E(r) cos n (θ)r/c 2 dr dφ. The target erosion rate E(r) was deduced from the target erosion pattern. A computer program has been written according to the model to calculate film thickness. Under specified sputtering...
The pumping action of molecular drag pumps is theoretically analyzed using the Clausing's integral equation. This equation allows one to calculate the transmission probability of a duct of arbitrary shape in molecular flow and it has been solved by different authors in the case of tubes with circular cross-section and stationary walls. This approach is extended to the case of a tube with moving walls,...
Thin film samples of In 2 Se 3 were prepared from synthesized polycrystalline In 2 Se 3 by a thermal evaporation technique. X-ray analysis show that the synthesized material has α-phase structure, while the as-deposited films have an amorphous structure. The films have β-phase structure after annealing at temperature 523 K. The conduction activation energy (E ...
Conductance of gases through different short circular passages at low density conditions is experimentally investigated. The main aim of the study is to verify the validity of the commonly used electrical analogy method of calculating flow resistance of a composite passage from the individual elements making the composite geometry. The range of Knudsen numbers covered in the experiments is from 0...
This paper reports on a small, planar, circular magnetron with target of 60 mm diameter for low pressure sputtering of thin films. A stable discharge can be sustained in the case when the plasma confinement near the target surface is improved by means of an assembly of permanent magnets placed above the target. It is shown that the polarity of permanent magnets plays a crucial role in the plasma confinement...
The reactive ion etching of low pressure chemical vapour deposited Si x C 1 - x layers (x= 0.5 and 0.8) on oxide covered Si(100) wafers has been investigated using in-situ ellipsometry, mass spectrometry and optical emission spectroscopy. Etch rates using SF 6 /O 2 and F 2 /Ar/O 2 plasmas have been monitored and the conditions identified under...
We have studied the modification of chromium coatings by nickel ion beams at a high energy (75 MeV) so that the range of the ions is many times the film thickness, which is of the order of 1 μM. At this energy, the rate of energy loss of ions is predicted to be fairly uniform over the entire thickness of the coating. The coating hardness increases significantly, even at moderate doses. The effect...
The paper describes a new type of spinning-rotor vacuum gauge, in which the rotor is quasi-disc-shaped and suspended by electrostatic fields. Electrostatic forces are also used to accelerate it to its operating speed. The instrument is intended as a transfer standard which might measure pressures in high vacuum to an ultimate reliable accuracy of 10 - 8 mbar (1 μPa) if possible. This has...
The investigation of the process of altered layer formation under ion bombardment for different TiO 2 modifications (rutile, anatase and the thermal oxide) and complex oxides (PbTiO 3 , La 2 TiO 5 , CaTiSiO 5 ) was carried out by means of XPS (X-ray photoelectron spectroscopy). The role of the closest chemical environment in the process of ion sputtering of...
During the cathodic arc enhanced metal ion etching process of steel substrates droplets are generated on the cathode which deposit on the substrate surface. The concentration of the droplets obviously depends upon the melting point of the target material. The number of droplets is much greater for TiAl than for Ti. The composition of the TiAl droplets also depends on their size. Large droplets tend...
Simulation of ion implantation into deep trenches demands the exact evaluation of ion fluxes backscattered from the sidewalls. In this paper an application of Boltzmann Transport Equation (BTE) to backscattered ion energy and angular distribution calculations is presented. Characteristic examples of grazing implantation of Sb, As and P in Si are considered and good agreement with Monte-Carlo (MC)...