1524. Technology and properties of evaporated cadmium selenide films

Classified abstracts 1518-1531 deposition of dielectric and metal thin films is described. The working chamber of the source is made of stainless steel with copper gaskets. The discharge chamber is made of molybdenum glass. The pumping system provides the initial pressure of 10-e torr. The high-frequency discharge is excited by a generator with frequency of 40 Mc and power of 200 W. A n ion beam with energy of about 1 keV was deposited on cleaved NaCI or glass substrates at room temperature. Neutralization of the substrate is not necessary. To obtain Al~O3, TiO2 and Sn films vapours of organic compounds were used. The dielectric films were deposited both from ion beams and in the region of high-frequency discharge. On extraction of the ion beam, the ion current increases with increasing vapour pressure of the compound decomposed in the discharge chamber. The working pressure was 3× 10-2 torr. The dielectric constant of the dielectric films deposited from the ion beam corresponds to its value for bulk materials. Films with lower dielectric constant are formed in the discharge region due to residual carbon content in the films. The deposition rate of tin films from the ion beam was greater than 1000/~/sec and the technique of film deposition from ion beams can be made sufficiently efficient. K A Osipov et al, Neorg Mater, 7 (6), 1971, 1051-1052 (in Russian). 30 1518. Measurement of porosity of vacuum aluminium coating. (USSR) A microscope method for quantitative determination of porosity and investigation of pore size distribution in vacuum deposited coatings of various thickness is presented. I L Roykh et al, Zavodsk Lab, 37 (3), 1971, 314-315 (in Russian). 3O 1519. Thermoelectric properties of TIBiS=, TIBiSe= and TIBiTe~ thin films. (USSR) Thermoelectric properties of TIBiS=, T1BiSe~ and T1BiTe2 thin films on glass substrates, prepared by thermal evaporation in vacuum at 5 × 10-6 torr from quartz crucibles, are investigated. It is found that TIBiTez films have high thermoelectric efficiency and can be used in film thermocouples. L G Voynova et al, Izv VUZ Fiz, No 5, 1971, 154-155 (in Russian). 30 1520. Photoelectric properties of p-n junctions in PbS single crystal films. (USSR) Photoelectric properties of p-n junctions in PbS single crystal films are investigated. The p-n junctions were prepared by deposition of n-type PbS single crystal films on cleaved NaC1, with subsequent deposition of a silver film on part of the PbS layer. Diffusion annealing in vacuum at 400°C results in formation of a p-n junction. L M Batukova, Izv VUZ Fiz, No 5, 1971, 146-148 (in Russian). 30 1521. Some characteristics of processes of metal erosion by focused laser radiation. (USSR) The evaporation of metals due to the action of laser radiation is experimentally investigated. The interaction of a laser beam with liquid particles of metal is studied in detail. The dependence of mass liberation on the specific power is experimentally determined for metals. It is shown that the mass liberation significantly depends on the purity of samples. B M Zhiryakov et al, Zh Tekh Fiz, 41 (5), 1971, 1037-1042 (in Russian). 3O 1522. Electron beam technique for the preparation of thin films from chemical compounds. (USSR) Investigations on preparation techniques for thin films using decomposition of chemical compounds by electron beam are reviewed. Advantages and disadvantages of electron-beam techniques are discussed. Theoretical principles of this technology are outlined, and basic systems for thin film preparation are described. Dielectric, metallic and semiconducting thin films obtained under the action of electron beam are usually deposited in apparatus similar to those for preparation of polymer films by electron-beam bombardment of the substrate in the presence of silicone vapours. To decompose different compounds 1-2 keV electron beams are employed with current density not higher than 2 mA/cm 2. The electron guns producing these electron beams can operate in relatively high pressures of 10-4 to 10-3 torr. Tungsten or thoriated tungsten cathodes are used. The mechanism of growth of polymer films is considered. Preparation of inorganic dielectric films in glow discharge and the preparation of metallic, semiconducting and carbide films by electron bombardment in the presence of vapours of chemical compounds, are described.

B A Vishnyakov and K A Osipov, book publd by Nauka Moscow 1970, 144 pages (in Russian). 30 1523. Epitaxial growth of films of germanium and silicon on epitaxially grown films of ionic crystals. (USSR) The possibility of growth of germanium and silicon single crystal films by thermal evaporation in vacuum is investigated. The substrates were prepared by thermal evaporation in vacuum at 10-5 torr of LiF=, CaFz or BaF2 films on NaCI or MgO cleaved crystals. V G Pynko et al, Proc Rost Krist Plen Polup, Novosibirsk 1970, 177183 (in Russian). 30 1524. Technology and properties of evaporated cadmium selenide films. (Poland) A vacuum apparatus is described which is used to obtain vacuum evaporated CdSe films using the technique of evaporation in vacuum. Needle-like CdSe single crystals are used as the raw material for evaporation. J Kryslewicz and J Woods, Pr Nauk Inst Technol Elektron PWr Ser Stud Mater, 2 (2), 1970, 3-10 (in Polish). 30 1525. Structure and electronic properties of films of the InSb-GaSb system. (USSR) Structure and electrical properties of films of the InSb-GaSb system, prepared by the discrete evaporation technique in vacuum, are investigated. V A Katsyan and Yn A Nikolskiy, Polup Soed Tverd Rsatv, Kishinev A N MoldSSR 1970, 107-113 (in Russian). 3O 1526. Multilayer thln-film structures with negative resistance. (USSR) Results of investigation of multilayer thin-film structures, prepared by vacuum evaporation, are presented. Ni, A1 and Cu metals, Te semiconductor and SiO and CaF~ dielectrics are used. Yu V Protasov and A P Ryumyantscv, Elektron Tekh Radiodet, 4, 1970, 59-66 (in Russian). 30 1527. Volt-ampere characteristics of structures with dielectric films of AI=O3. (USSR) Volt-ampere characteristics of Si-A12Os-A1 and Si-SiO=-AI=O3-A1 structures are investigated. Al=O3 films were prepared by reactive sputtering of A1 in oxygen-argon plasma. V A Goldfarh et al, Radiofiz Mikroelektron, Voronezh 1970, 95-97 (in

Russian). 30 1528. Stability of M O S structures based on niobium oxide. (USSR) Stability and surface charge in the Si-Nb~Os-A1 system are investigated. The NbaO5 films were deposited by sputtering a metallic target in oxygen plasma at an oxygen pressure of 8 × 10-4 torr. V V Kryachko et al, Radiofiz Mikroelektron, Voronezh 1970, 92-94 (in

Russian). 30 1529. Gallium ursenide mixer diode with Schottky barrier. (USSR) Construction and preparation of an ultrahigh frequency mixer diode are described. Construction is based on planar-epitaxial structure with utilization of epitaxy, ion-plasma deposition of the protective film, and vacuum deposition. V F Kolomeytsev et al, Elektron Tekh Polup Prib, 5, 1970, 3-11 (in

Russian). 30 1530. Some properties of hetero-junctions based on silicon single crystals and cadmium and zinc selenide films. (USSR) Results of electrical property investigations on pSi-nCdSe and pSinZnSe heterojunctions, prepared by vacuum evaporation of selenide films on silicon single crystal surfaces are presented. Optimum film thicknesses are determined. M V Kot et al, Polup Soedin Tverd Rastv, Kishinev A N Mold SSR 1970, 49-59 (in Russian). 30 1531. Some properties of thin films of V, Ti, Ta and Nb nitrides. (USSR) Manufacturing technology for films of V, Ti, Ta and Nb nitrides based on the technique of reactive ion-plasma sputtering is described. Electrical and physical properties of the films are investigated. V F Synorov et al, Tr Voronezh Inst, No 74, 1971, 65-68 (in Russian). 621