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2116. Implantation of heavy ions into silicon single crystals
Classified abstracts 2112-2125 investigated. The 50 keV boron ions were implanted at room temperature up to a dose of 6 x 10 ~5 cm -2. N P Dikiy et al, Fiz Tekh Polup, 9 (3), 1975, 592-594 (in Russian). 11 2112. Influence of preamorphization on concentration profiles of boron implanted into silicon. (Germany) A study of the effect of amorphization on distribution profiles of 40 keV boron implants in silicon after post-implantation annealing is reported. Amorphization was achieved by bombardment with Si ions. It is found that the preamorphization acts as a limiting factor for diffusion. (Poland) A Barcz et al, Phys Stat Sol (a), 27 (2), 1975, K65-K68. 11 2113. The temperature dependence of the Hall effect in implanted layers prepared by bombardment of silicon with arsenic ions. (USSR) The influence of temperatures of ion implantation and subsequent annealing in a vacuum better than 10 -5 torr on the temperature dependence of the Hall effect is investigated in implanted layers prepared by bombardment of silicon with 30 keV As + ions at doses ranging from 6 × 10 ~3 to 3.7 × 1015 cm -z. The influence of implantation temperature on formation and annealing of compensation centres of irradiation origin in implanted layers is found. R M Aranovich et al, Fiz Tekh Polup, 9 (2), 1975, 204-209 (in Russian). 11 2114. On electrical activity of boron and phosphorus implanted in silicon. (USSR) Using the method of measurement of electrical conductivity and the Hall effect at gradual chemical removal of surface layers, distribution of concentrations of holes, electrons, boron atoms and P atoms in Si is investigated after implantation of 40 keV boron ions and 100 keV phosphorus ions. Yu N Shutov et al, Izv VUZFiz, No 4, 1975, 118-119 (in Russian). 11 2115. Ion-implanted layer: new material for recording holograms. (USSR) A new method for recording and storage o f optical information is investigated. The method is based on preliminary bombardment of Si and Ge single crystals by fast ions. This method enables one to prepare controlled amorphous layer on surface of single crystals and to introduce electrically active impurities. Si and Ge single crystals have been irradiated in a vacuum chamber by N 14, O t6, Ne 2°, psi, Ar 4° and Sb T M ions with energies ranging from 10 to 370 keV. The dose was varied in the range of 6 × 1012 to 6 × 1016 ion/cm z. E I Shtyrkov et al, Optika Spektroskop, 38 (5), 1975, 1031-1034 (in
Russian). 11 2116. Implantation of heavy ions into silicon ~ngle crystals. (USSR) Using the method of radioactive isotopes, distribution of concentration of 45 keV implanted ions with mass ranging from 82 to 169 into silicon single crystal is experimentally determined. Experimental results are compared with theoretical calculations. M Kiselevich et at, Fiz Tverd Tela, 17 (4), 1975, 1080-1084 (in Russian). 11 2117. Proton backscattering study of radiation damage of CdS single crystals. (USSR) Using the method of 700 keV proton backscattering, radiation damage is investigated in CdS semiconductor single crystals implanted with 140 keV sodium ions at doses ranging from l0 t's to 2 × 10 t6 ion/em 2. A N Grigorev et al, Fiz Tekh Polup, 9 (6), 1975, 1147-1149 (in Russian). 11 2118. Absorption spectra investigation of formation of defects in Si irradiated with ions of various mass. (USSR) The process of accumulation of defects at implantation of 4He, 7Li, 11B, x2C, 2°Ne,4°Ar and 121Sb 80 keV ions into single crystal silicon is investigated. Experimental results are discussed. E K Baranova, Fiz Tekh Polup, 9 (6), 1975, 1154-1156 (in Russian). 11 2119. On the kinetics of charging semiconductor surfaces at adsorption. (USSR) The kinetics of changes in surface and electrical conductivity of semiconductor during the adsorption process is analysed. It is shown that both monotomic and nonmonotomic experimental time dependences 488
of electrical conductivity at adsorption can be explained by accounting the finite rate of charge change of slow surface states. S N Kozlov, lzv VUZ Fiz, No 2, 1975, 116--120 (in Russian). II 2120. Kinetic characteristics of oxygen adsorption on PbS films. (USSR) Kinetic characteristics of oxygen adsorption on surface of epitaxial n-PbS films are investigated at temperatures of 298 and 373 K using quartz balances. Sticking coefficients of 5 × 10 -9 and 1 × 10 -9 at 373 and 298 K, respectively, have been determined. It is concluded that atomically clean PbS surface can be maintained in a vacuum of l 0- 7 torr for several days. A E Bazhanova and Yu A Zarifyants, Vestn Mosk Univers Fiz Astronora, 15 (3), 1974, 360-362 (in Russian). 11 2121. Desorption of cerium atoms from tungsten surface. (USSR) The results of investigation of the process of thermal desorption of cerium atoms from surface of W in a field emission microscope at a residual gas pressure of 10- ~o torr are presented. The average heat of Ce evaporation from W is determined to be 4.7 eV. B M Palyukh and T P Smereka, Visnik Lvov Univers Ser Fiz, No 9, 1974, 110-112 (in Ukrainian). 11 2122. Mass-spectrometric investigation of early stages of silicon oxidation. (USSR) Using the flash-filament method, oxidation of silicon surface, cleaved by heating to 1200°C in an ultra-high vacuum of 10 -9 torr for several minutes, is investigated. Oxidation of the samples took place at oxygen pressure of 10 -6 torr and at room temperature or 630°C. It is found that at an early stage of oxidation the kinetics of silicon monoxide desorption considerably varies with increasing oxygen exposure. To explain the experimental results it is proposed that already at an adsorption coverage of 1 to 2 atomic layers on surface, an oxide film is formed, the evaporation of which in the form of SiO can proceed only after its reduction by the silicon substrate. A A Frantsuzov and N I Makrushin, Zh Tekh Fiz, 45 (3), 1975,600-603
(in Russian). 11 2123. Evidence for doubly ionized native donors in HgSe. (Germany) The electron concentration in HgSe has been measured as a function of partial Hg and Se pressures in ambient atmosphere in the pressure range of 10 -7 to 10- l torr. An evidence for doubly ionized donors in HgSe has been found. It is shown that mainly interstitial Hg atoms contribute to the conduction mechanism in HgSe. (Japan) K Kumazaki and A Odajima, Phys Stat Sol(a), 27 (1), 1975, K25-K27. 11 2124. Channelling evidence for a shallow trapping configuration of copper interstitials at gold atoms in a Cu-0.05 at per cent Au crystal. (Germany) From an analysis of the energy spectra of backscattered 1 to 2 MeV He + ions from a Cu-~).05 atomic per cent Au crystal, it is shown that Au atoms were not appreciably displaced from lattice sites by irradiation with 0.5 to 1.5 MeV He + ions at 40 to 70 K. Thus a dump-bell Cu-Au configuration is not created, a more shallow type of trapping is indicated. However, the Au atoms do become displaced from lattice sites during stage III recovery (200 to 320 K). M L Swanson et al, Phys Stat Sol (a), 27 (1), 1975, 281-284. 11 2125. Preparation of stepped tungsten single crystal surfaces. (Germany) Tungsten single crystal surfaces oriented at a small angle with respect to a low-indexed plane can show a terraced structure characterized by flat terraces of the low-indexed plane with monatomic steps at equal distances. Stepped surface can play an essential role in surface processes (adsorption, catalysis). The preparation of a high-indexed tungsten single crystal surface is carried out in three subsequent stages: crystallographic orientation by means of the Laue technique, metallographic machining, grinding, lapping, polishing, and annealing in ultra-high vacuum. The stepped tungsten single crystal surfaces from 6 to 10 mm in diameter showing an accuracy of better than 15 in orientation, an overall flatness of better than 1/10 of a wavelength of the Na-D line, a surface roughness of smaller than 0.05 tLm, and without destruction detectable by LEED have been prepared. R Butz et al, Phys Star Sol (a), 27 (1), 1975, 205-212.
Russian). 11 2116. Implantation of heavy ions into silicon ~ngle crystals. (USSR) Using the method of radioactive isotopes, distribution of concentration of 45 keV implanted ions with mass ranging from 82 to 169 into silicon single crystal is experimentally determined. Experimental results are compared with theoretical calculations. M Kiselevich et at, Fiz Tverd Tela, 17 (4), 1975, 1080-1084 (in Russian). 11 2117. Proton backscattering study of radiation damage of CdS single crystals. (USSR) Using the method of 700 keV proton backscattering, radiation damage is investigated in CdS semiconductor single crystals implanted with 140 keV sodium ions at doses ranging from l0 t's to 2 × 10 t6 ion/em 2. A N Grigorev et al, Fiz Tekh Polup, 9 (6), 1975, 1147-1149 (in Russian). 11 2118. Absorption spectra investigation of formation of defects in Si irradiated with ions of various mass. (USSR) The process of accumulation of defects at implantation of 4He, 7Li, 11B, x2C, 2°Ne,4°Ar and 121Sb 80 keV ions into single crystal silicon is investigated. Experimental results are discussed. E K Baranova, Fiz Tekh Polup, 9 (6), 1975, 1154-1156 (in Russian). 11 2119. On the kinetics of charging semiconductor surfaces at adsorption. (USSR) The kinetics of changes in surface and electrical conductivity of semiconductor during the adsorption process is analysed. It is shown that both monotomic and nonmonotomic experimental time dependences 488
of electrical conductivity at adsorption can be explained by accounting the finite rate of charge change of slow surface states. S N Kozlov, lzv VUZ Fiz, No 2, 1975, 116--120 (in Russian). II 2120. Kinetic characteristics of oxygen adsorption on PbS films. (USSR) Kinetic characteristics of oxygen adsorption on surface of epitaxial n-PbS films are investigated at temperatures of 298 and 373 K using quartz balances. Sticking coefficients of 5 × 10 -9 and 1 × 10 -9 at 373 and 298 K, respectively, have been determined. It is concluded that atomically clean PbS surface can be maintained in a vacuum of l 0- 7 torr for several days. A E Bazhanova and Yu A Zarifyants, Vestn Mosk Univers Fiz Astronora, 15 (3), 1974, 360-362 (in Russian). 11 2121. Desorption of cerium atoms from tungsten surface. (USSR) The results of investigation of the process of thermal desorption of cerium atoms from surface of W in a field emission microscope at a residual gas pressure of 10- ~o torr are presented. The average heat of Ce evaporation from W is determined to be 4.7 eV. B M Palyukh and T P Smereka, Visnik Lvov Univers Ser Fiz, No 9, 1974, 110-112 (in Ukrainian). 11 2122. Mass-spectrometric investigation of early stages of silicon oxidation. (USSR) Using the flash-filament method, oxidation of silicon surface, cleaved by heating to 1200°C in an ultra-high vacuum of 10 -9 torr for several minutes, is investigated. Oxidation of the samples took place at oxygen pressure of 10 -6 torr and at room temperature or 630°C. It is found that at an early stage of oxidation the kinetics of silicon monoxide desorption considerably varies with increasing oxygen exposure. To explain the experimental results it is proposed that already at an adsorption coverage of 1 to 2 atomic layers on surface, an oxide film is formed, the evaporation of which in the form of SiO can proceed only after its reduction by the silicon substrate. A A Frantsuzov and N I Makrushin, Zh Tekh Fiz, 45 (3), 1975,600-603
(in Russian). 11 2123. Evidence for doubly ionized native donors in HgSe. (Germany) The electron concentration in HgSe has been measured as a function of partial Hg and Se pressures in ambient atmosphere in the pressure range of 10 -7 to 10- l torr. An evidence for doubly ionized donors in HgSe has been found. It is shown that mainly interstitial Hg atoms contribute to the conduction mechanism in HgSe. (Japan) K Kumazaki and A Odajima, Phys Stat Sol(a), 27 (1), 1975, K25-K27. 11 2124. Channelling evidence for a shallow trapping configuration of copper interstitials at gold atoms in a Cu-0.05 at per cent Au crystal. (Germany) From an analysis of the energy spectra of backscattered 1 to 2 MeV He + ions from a Cu-~).05 atomic per cent Au crystal, it is shown that Au atoms were not appreciably displaced from lattice sites by irradiation with 0.5 to 1.5 MeV He + ions at 40 to 70 K. Thus a dump-bell Cu-Au configuration is not created, a more shallow type of trapping is indicated. However, the Au atoms do become displaced from lattice sites during stage III recovery (200 to 320 K). M L Swanson et al, Phys Stat Sol (a), 27 (1), 1975, 281-284. 11 2125. Preparation of stepped tungsten single crystal surfaces. (Germany) Tungsten single crystal surfaces oriented at a small angle with respect to a low-indexed plane can show a terraced structure characterized by flat terraces of the low-indexed plane with monatomic steps at equal distances. Stepped surface can play an essential role in surface processes (adsorption, catalysis). The preparation of a high-indexed tungsten single crystal surface is carried out in three subsequent stages: crystallographic orientation by means of the Laue technique, metallographic machining, grinding, lapping, polishing, and annealing in ultra-high vacuum. The stepped tungsten single crystal surfaces from 6 to 10 mm in diameter showing an accuracy of better than 15 in orientation, an overall flatness of better than 1/10 of a wavelength of the Na-D line, a surface roughness of smaller than 0.05 tLm, and without destruction detectable by LEED have been prepared. R Butz et al, Phys Star Sol (a), 27 (1), 1975, 205-212.