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1131. Epitaxial growth of germanium substrates cleaned and heated by electron bombardment
Classified abstracts 1125-1138 tendency is observed when CdSe films deposited in the presence of CdCl2 were heat treated in nitrogen atmosphere. The peak of the thermoelectric current curve depended on the atmosphere, and the equilibrium curve for air was greatly different from that for nitrogen. These phenomena may be explained by the fact that absorption and desorption of oxygen becomes easier in relation to the sulphur filling in Se holes. From the nature of the temperature dependence of the current, it is assumed that oxygen-ion is adsorbed on the surface and the donor level is located 0.54 eV from the conduction band. K Shimizu, J Chem Soe Japan, Pure ('hem Sec, 87 (6), June 1966, 549-552 (in Japanese). 30 1125. Preparation and properties of vacuum deposited CdS and CdSe films. (Japan) In order to evaluate the applicability of vacuum deposited CdS and CdSe films to thin film active devices, the resistivity, Hall mobility, optical properties, crystalline state and contact properties with various metals were studied as a function of parameters in preparation and processing. Both films showed quite similar behaviour in crystalline state and contact properties, while larger Hall mobilities and lower carrier concentrations were readily obtained in the CdSe films. Y Terasaki et al, Elec Comm Lab Rev, 14, 1966, 425-440. 3O 1126. Preparation and properties of tin dioxide (stannic oxide) deposited by cathodic sputtering. (USSR) A method of producing stannic oxide films by cathodic sputtering in such a way as to enable doping impurities to be introduced directly during the process of deposition is described. The discharge chamber is attached to a standard pumping system comprising backing and diffusion pumps and furnished with the usual vacuum gauges. Provision is made for the introduction of foreign gases from auxiliary cylinders through a reducing valve. Semiconducting stannic oxide films with conductivities between l0 -s and 102 ~ 1 cm-1 may be produced in this way. V M Vainshtein, Optiko-Mekhan Promyshl, No l, 1967, 46 (in Russian) 30 1127. Producing thin films of refractory materials. (USSR) A number of methods of producing thin films of refractory metals are reviewed. Thus, cathode sputtering is especially useful for producing thin films of radium, osmium, or tantalum of high corrosion resistance and good mechanical stability under thermal stress. The vacuum electric arc is widely used in preparing chemically pure metals of high melting point: tantalum, niobium, vanadium, titanium and iron, as well as stainless steel. Another method, based on a sprung point contact between two electrodes made of the metal to be evaporated, is of particular value in preparing thin films of tungsten, molybdenum, and tantalum; these metals may also conveniently be treated by electron bombardment. The structure and properties of some typical thin films obtained by these methods are discussed. M G Servetskaya, Elektron Obrabot Material, No 2, 1966, 62 (in
Russian). 3O 1128. Structure of uranium in thin films. (USSR) Attempts to produce thin films of fl-uranium by vacuum evaporation from a tungsten spiral on to a rock salt cleavage are described. Films released into the atmosphere after vacuum evaporation rapidly oxidized. Films produced directly in the electron-diffraction camera without atmospheric contamination still contained appreciable quantities of uranium oxide, UP2; even at residual pressures of 10 -4 torr the uranium oxidized quite rapidly, giving diffuse electrondiffraction haloes, characteristic of cubic UPs. In no case was any of the tetragonal phase (fl-uranium) formed. L D Kolomiets, Kristallografiya, 12 (1), 1967, 154 (in Russian). 30 1129. Producing carbon films for substrates and replicas by the thermal evaporation of carbon in a rough vacuum gas discharge. (USSR) A simple method of producing carbon films for substrates and replicas in a rough vacuum (10 -~ to 10 -2 tort) by the thermal evaporation of carbon electrodes in an alternating electric field is proposed. This method gives strong films up to 800 A thick and suitable for electron-microscope replicas of objects liable to evaporate at the lower pressures traditionally used in carbon-film production. The film thickness depends on the evaporation time, the pressure between the carbon electrodes, the current passing through the electrodes, the distance between object and discharge, and the
applied discharge voltage. The object suffers none of the severe heating and/or ionic etching associated with existing methods. M ! Kozlovskii, Zavodsk Lab, 33 (2), 1967, 198-199 (in Russian). 30 1130. Some problems in thickness distribution of thin films deposited by evaporation. (Poland) Equations for evaluation of thickness and its distribution over an area are derived for the vacuum deposition of thin films from point and area sources onto a plate. K Lelakowska, Przeglad Elektron, 7, 1966, 387-390 (in Polish). 30 1131. Epitaxial growth of germanium substrates cleaned and heated by electron bombardment. (Germany) Simultaneous evaporation onto Ge substrates and electron bombardment of the surface removed the oxide film and established conditions not too far from thermodynamic equilibrium. Well-oriented tetrahedral growth was observed. The dependence of the density of the etch patterns on the substrate temperatures (400-800°C) and bombarding power are indicated. J Pferfer, Phys Status Solidi, 17, 1966, K I 5 - K l 8 . 30 1132. Metallic coatings on paper and plastics. (Germany) Vacuum and electrolytic deposition of metals on paper and plastics are described and compared. Methods, materials and some applications are briefly discussed. C Enke, Metall Reinigung Vorbehandhmg, 15, 1966, 119-121 (in
German). 3O 1133. Obtaining a superconductive cavity by vacuum deposition. (France) The cavity was produced by vacuum depositing at 5× l0 6 torr, high purity lead on the highly polished inner wall of art OFHC copper cylinder sealed with indium joints to withstand immersion in liquid helium. N Viet and F Biquard, Compt Rend, 262B, 1966, 590-592 (in French). 30 1134. Properties of cadmium tellurlde diodes and their application to nuclear particle detection. (France) Cd-Te p-n junctions were prepared by vacuum depositing a high resistivity Cd-Te film on an indium-doped n-type Cd-Te crystal, followed by flash deposition of Cu2Te and modification of the inverse-current characteristic by vacuum annealing for 30 minutes at 250°C. V Delcroix et al, Compt Rend, 262B, 1966, 1223-1226 (in French). 30 1135. Preparation of monocrystalline gold films without substrate. (France) Perfectly continuous monocrystalline gold films have been prepared by evaporation onto silver previously deposited on mica. The films, of about 1 cm z area and 40 microns or more thick can be successfully separated from the substrate. M lsaia and J Casset, Compt Rend Acad Sei (France), 263B, 1966, 1041-1043 (in French). 3O 1136. Deposition of silica films by the glow discharge technique. (USA) Noncrystalline SiP2 films were deposited on various substrates at low temperatures and pressure by decomposing tetraethoxysilane by 02 species from an R F induced oxygen plasma. The rate of deposition was controlled by physical adsorption. D R Secrist and J D Mackenzie, J Electrochem Soc, 113, 1966, 914-920. 30 1137. Vapour phase growth of gallium arsenide microwave diodes. (USA) GaAs microwave diodes were prepared by a novel vapour phase growth technique with the highest combination of reverse breakdown voltages and cut off frequencies reported. Structures of GaAs can be prepared with a high purity layer directly next to layers doped either n- or p- type over a wide range of selected resistivities. High quality abrupt p-n junctions can be incorporated in these crystals without sacrifice of desired bulk properties. J J Tietjen et al, Solid State Electron, 9, 1966, 1049-1053. 30 1138. The structure of silver films deposited on mica substrates, in ultrahigh vacuum. (Netherlands) The structure of Ag films prepared in UHV by deposition onto
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Russian). 3O 1128. Structure of uranium in thin films. (USSR) Attempts to produce thin films of fl-uranium by vacuum evaporation from a tungsten spiral on to a rock salt cleavage are described. Films released into the atmosphere after vacuum evaporation rapidly oxidized. Films produced directly in the electron-diffraction camera without atmospheric contamination still contained appreciable quantities of uranium oxide, UP2; even at residual pressures of 10 -4 torr the uranium oxidized quite rapidly, giving diffuse electrondiffraction haloes, characteristic of cubic UPs. In no case was any of the tetragonal phase (fl-uranium) formed. L D Kolomiets, Kristallografiya, 12 (1), 1967, 154 (in Russian). 30 1129. Producing carbon films for substrates and replicas by the thermal evaporation of carbon in a rough vacuum gas discharge. (USSR) A simple method of producing carbon films for substrates and replicas in a rough vacuum (10 -~ to 10 -2 tort) by the thermal evaporation of carbon electrodes in an alternating electric field is proposed. This method gives strong films up to 800 A thick and suitable for electron-microscope replicas of objects liable to evaporate at the lower pressures traditionally used in carbon-film production. The film thickness depends on the evaporation time, the pressure between the carbon electrodes, the current passing through the electrodes, the distance between object and discharge, and the
applied discharge voltage. The object suffers none of the severe heating and/or ionic etching associated with existing methods. M ! Kozlovskii, Zavodsk Lab, 33 (2), 1967, 198-199 (in Russian). 30 1130. Some problems in thickness distribution of thin films deposited by evaporation. (Poland) Equations for evaluation of thickness and its distribution over an area are derived for the vacuum deposition of thin films from point and area sources onto a plate. K Lelakowska, Przeglad Elektron, 7, 1966, 387-390 (in Polish). 30 1131. Epitaxial growth of germanium substrates cleaned and heated by electron bombardment. (Germany) Simultaneous evaporation onto Ge substrates and electron bombardment of the surface removed the oxide film and established conditions not too far from thermodynamic equilibrium. Well-oriented tetrahedral growth was observed. The dependence of the density of the etch patterns on the substrate temperatures (400-800°C) and bombarding power are indicated. J Pferfer, Phys Status Solidi, 17, 1966, K I 5 - K l 8 . 30 1132. Metallic coatings on paper and plastics. (Germany) Vacuum and electrolytic deposition of metals on paper and plastics are described and compared. Methods, materials and some applications are briefly discussed. C Enke, Metall Reinigung Vorbehandhmg, 15, 1966, 119-121 (in
German). 3O 1133. Obtaining a superconductive cavity by vacuum deposition. (France) The cavity was produced by vacuum depositing at 5× l0 6 torr, high purity lead on the highly polished inner wall of art OFHC copper cylinder sealed with indium joints to withstand immersion in liquid helium. N Viet and F Biquard, Compt Rend, 262B, 1966, 590-592 (in French). 30 1134. Properties of cadmium tellurlde diodes and their application to nuclear particle detection. (France) Cd-Te p-n junctions were prepared by vacuum depositing a high resistivity Cd-Te film on an indium-doped n-type Cd-Te crystal, followed by flash deposition of Cu2Te and modification of the inverse-current characteristic by vacuum annealing for 30 minutes at 250°C. V Delcroix et al, Compt Rend, 262B, 1966, 1223-1226 (in French). 30 1135. Preparation of monocrystalline gold films without substrate. (France) Perfectly continuous monocrystalline gold films have been prepared by evaporation onto silver previously deposited on mica. The films, of about 1 cm z area and 40 microns or more thick can be successfully separated from the substrate. M lsaia and J Casset, Compt Rend Acad Sei (France), 263B, 1966, 1041-1043 (in French). 3O 1136. Deposition of silica films by the glow discharge technique. (USA) Noncrystalline SiP2 films were deposited on various substrates at low temperatures and pressure by decomposing tetraethoxysilane by 02 species from an R F induced oxygen plasma. The rate of deposition was controlled by physical adsorption. D R Secrist and J D Mackenzie, J Electrochem Soc, 113, 1966, 914-920. 30 1137. Vapour phase growth of gallium arsenide microwave diodes. (USA) GaAs microwave diodes were prepared by a novel vapour phase growth technique with the highest combination of reverse breakdown voltages and cut off frequencies reported. Structures of GaAs can be prepared with a high purity layer directly next to layers doped either n- or p- type over a wide range of selected resistivities. High quality abrupt p-n junctions can be incorporated in these crystals without sacrifice of desired bulk properties. J J Tietjen et al, Solid State Electron, 9, 1966, 1049-1053. 30 1138. The structure of silver films deposited on mica substrates, in ultrahigh vacuum. (Netherlands) The structure of Ag films prepared in UHV by deposition onto
365