5083. Thickness uniformity of evaporated layers in theory and practice

5083. Thickness uniformity of evaporated layers in theory and practice

Classified abstracts 5081-5089 moves from the oxygen-rich lop Cr layer through the oxygen-depleted transition region into the Cu substrate. (Austria) ...

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Classified abstracts 5081-5089 moves from the oxygen-rich lop Cr layer through the oxygen-depleted transition region into the Cu substrate. (Austria) N Klaus, d Vac Sci Technol, 19 (2). 1981, 201 204. 30

5081. Mechanical and tribological behaviour of ion plated soft metallic coatings. (West Germany) Ion plating is a fairly new coating technique. A great variety of materials can be deposited by this technique. For the deposition of hard, wear resistant coatings dc-diode-ion-plating has to be changed to increase the ionization. In this investigation this is done by a further electrode and a hot filament. The increased ionization has a great influence on the properties of the coatings. The object of this investigation is the study of the influence of the increased ionization on the adhesion, the structure and the tribological properties of ionplated soft metalic coatings. K H KIoos et al, Vakuum Teclmik, 30 (2), 1981, 35 42 (in German). 30 5082. Ion plating and ionization. (West Germany) Ion plating is a fairly new surface coating technique but with surprising results concerning adhesion, structure and uniformity of the coating. It is a well established fact that the intensity of ionization is the most important parameter in ion plating. To enhance the ionization during sputter cleaning and ion plating a conventional diode ion plating system was changed to a triode- and tetrode-type and also a magnetic coil was used. "~he characteristics of these different systems have been studied and are here reported. K H Kloss el al, Vakuum Technik, 30 (1). 1981, 15-21 (in German). 30

5083. Thickness uniformity of evaporated layers in theory and practice. (West Germany) The efficiency of thin films strongly depends on their geometrical thickness. In exacting applications (e.g. optical thin films) an extremely high film thickness uniformity is required over the entire substrate surface. It is shown by means of a model how to calculate the film thickness distribution on plane or spherical substrate areas. The unknown parameters of the evaporation distribution of the sources have to be experimentally measured in every application to a special case. Only then it is possible to achieve uniformly thick films by systematic variation of the distances between source, substrates and axis of rotation or by installing determined shutter for correcting thickness variations. Using computer systems eases the calculation of optimum thickness uniformity. By means of two examples the application of the calculation is shown not only by optimizing the geometric evaporation positions but also by using a correction shutter. G Deppisch, Vakuum Technik, 30 (3), 1981, 67-78 (in German). 30

5084. Film thickness uniformity of sputter deposited layers~omparison between calculation and practical results. (West Germany~ The technology of sputtering, particularly the recent tempestious development of magnetically enhanced high-rate sputtering created a real alternative with reference to the conventional high vacuum coating technique employing thermally heated evaporation sources. The demanded thickness uniformity of the deposited films remained unchanged high. This paper reports a calculating model which determines thickness distributions in the substrate plane below the sputter cathodes not only for static sputter deposition but also for moving substrates. Moreover it is possible to calculate the geometrical shape of diaphragm apertures, enforcing uniformly thick films upon the substrates. The efficiency of the calculating model is demonstrated by means of practical examples. G Deppisch, Vakuum Teclmik, 30 (4), 1981, 106-115 (in German). 30

5085. On the propertiesofion-beam sputtered CulnSe 2 thin films. (France) Possible and specific applications of CulnSe., thin films as infrared detectors and solar cells have been demonstrated and are of greatest interest. Difficulties encountered in growing CulnSe 2 thin films of known stoichiometry and electrical properties are the actual main problems for well-suited device fabrication. In the present work. ternary CulnSe 2 thin films were grown by ion-beam sputtering on different substrates: SiO 2. NaCI, Cu and Al20 3. The characteristics of the as-grown films were checked by electron-diffraction, resistivity, room-temperature optical gap measurements and are compared to bulk properties. In addition, quantitative AES and SIMS were performed in order to measure the elemental composition of the synthctized films. Electron-diffraction patterns indicate that ion-beam sputtered CulnSc 2 thin films have the expected chalcopyrite structure while the optical gap is found to be near


I eV. It is shown that resistivity ranged from 1 0 ~ [2cm to several 103 ~ c m and is critically dependent upon stoichiometry of ternary thin films which are fc,und to be n type or p type with the same chalcopyrite structure under different experimental conditions. SIMS secondary ionyields of molecular ions like lnCu ~, l n S e ' , InCu~, InaSe ' and Cu Se* were measured and were related to the AES elemental composition of CulnSe 2 thin films. F Bonhoure el al, Le Vide. 207, 1981, 541 551. 3O 5086. Electrical properties of SiO2, and Si3N.~ dielectric layers on InP. (USA~ Plasma-enhanced chemical vapour deposition techniques using SiH.~ and N2O [lave been employed to deposit SiO 2 insulating layers on n-type InP substrates. Si3N.~ layers have been deposited employing the reaction between Sill 4 and NH 3. Metal-insulator-semiconductor capacitors have been fabricated from these structures and their interracial properties have been measured using capacitance-voltage techniques. The amount of surface potential modulation achieved using SiO, layers is process dependent and varied from 0.4 to 1.2 V. The modulation observed using Si3N.~ layers was consistently about 0.6 V. The a m o u n t of trapped interfacial charge in the SiO 2 layers is shown to be given by a fixed charge plus a charge directly proportional to the electric field in the oxide. A compilation of data for SiO 2 layers on other semiconductors, including silicon, illustrates that this is apparently a universally-observed phenomenon. It is shown that this charging behaviour gives the familiar ushaped density of states curve. As an alternative to the present method of characterizing interfacial charging behaviour, an interfacial quality factor AQ~,AQ~,. is proposed that is independent of the semiconductor band gap or impurit? level. L G Me(nets, J l,'ac Sci Teclmol, 19 13), 1981, 373 379. 30 5087. Emission of electrons and positive ions upon fracture of oxide films. (USA) During tensile deformation of oxide-coated aluminium, small cracks a few hundredths of a mm in length occur in the oxide film. During and following the appearance or elongation of these cracks, electron emission lEE) and positive ion emission (PIE) tire detected in the surrounding vacuum. Crack propagation in the oxide coating can be detected with an acoustic emission (AEI transducer. Correlations between charged particle emission and film fracture can then be determined. A comparison of rates of EE, PIE and AE. the distribution of the number of electrons or ions per burst, and the time distributions relative to crack propagation of both EE and PIE are presented. The time distributions indicate distinct differences in the rate limiting steps governing EE and PIE. J T Dickinson et al, J I'uc Sci Technol, 18 12), 1981, 238 241. 3O

5088. Electron spectroscopy of ion beam and hydrocarbon plasma generated diamondlike carbon films. (USA) Mechanically hard, electrically insulating (diamondlikelcarbon thin films have been produced by low energy carbon ion beam deposition and by decomposition of butane gas. Deposition parameters are presented for these two methods. The ion beam films can be produced with or without a secondary discharge in the ion source and the parameters are given for these two modes of operation. ESCA and electron energy loss (EELSI techniques have been used to examine the electronic character of these films. ESCA carbon 11.'0spectra show that the films are composed mostly of C - - C bonds and that a negative bias is important to eliminate C - - H bonds from the butane generated films. EELS data show that the films arc more diamondlike in that the strong graphite feature at 6.5 eV is not evident in these lilms. A m o n g the other measured properties of these fihns, the refractive index ~2.3 at 5 j~m) and hardness 11850 knoop I are in keeping with the diamondlike character of these films. T J Moravec and T W Orent, ,/ I'ac Sci Teelmol, 18 12), 1981. 226 228.

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5089. Coating of preformed pieces with TiN by high rate sputtering. ( West Germany) The coating of shaped objects with hard TiN films can be achieved with particular success when the sputtering takes place from two high rate cathodes situated opposite each other. If. in addition, a negative voltage is applied to the substrates and the magnetic fields of the cathodes as well as the power density at the targets are suitable tuned, it is possible to obtain similar discharge conditions as are prevailing during ion plating. Under