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1452. Ion implantation—new technique for semiconductor doping
Classified abstracts 1452-1463 16 1452. Ion implantation--new technique for semiconductor doping. (USSR) Basic trends in the application of ion beams in semiconductor technology are considered. The effect of ion penetration in amorphous and crystalline samples is analyzed in detail. Influence of the energy and mass incident ions, and orientation of the substrate on the penetration depth of ions in the solid is discussed. Methods for calculation of the average penetration depth are presented. The channeling effect is discussed. Data on the penetration depth of ions of boron, phosphorus, nitrogen and arsenic in silicon substrates oriented in the directions (110), (111) and (100) are given. Other topics covered include: methods for calculating the critical angle of channeling and energy loss of ideally channeling particles; the distribution functions for different doping materials implanted in silicon and germanium in directions (110), (111) and (100) for different energies and doses of ions; approximative methods for obtaining the profile of distribution of the implanted ions; problems on the distribution of radiation defects in depth of the bombarded material, their nature, the thickness of the damaged layer and removal of radiation defects; and the influence of annealing. V V Rudnev et al, Elektron Tekh Materialy, 5, 1970, 148-149 (in
Russian). 16 1453. Sorption of water vapour by metals and alloys. (USSR) Methods for determination of sorption capability of the surfaces of copper, nickel, kovar, and iron for water vapour have been developed. Methods have also been developed for investigation of the desorption of water vapour from these materials during vacuum heat treatment. Water marked with tritium was used as a radioactive tracer. It is shown that the sorption capability of metal and alloy surfaces determined by this method depends on the cleaning procedures used on the surfaces examined. Sorption of water vapour from the samples after chemical polishing and heating in dry and moist hydrogen is investigated. The minimum quantity of water remains on the surface of metals after heating in hydrogen. After storage in air the samples subjected to chemical treatment and heating show an increase in sorption capability of 30 per cent. Storage of similar samples for 5 to 10 days in an atmosphere saturated with water vapour results in a two- to three-fold increase in the sorption capability. Yu M Kuzmin et al, Elektron Tekh Elektron SVCh, 2, 1971, 99-105
(in Russian). 16 1454. Interaction of non-evaporating getters with hydrogen and carbon monoxide. (USSR) Interaction of porous non-evaporating getters, of various compositions, with carbon monoxide and hydrogen, is investigated in the temperature range from room to 800°C. The dependences of the relative average sorption rates for carbon monoxide and hydrogen are presented, from which the optimum thermal regime of getter operation can be chosen for vacuum devices, taking account of requirements to residual gas composition in regard to the relative carbon monoxide to hydrogen concentrations. M F Boyarina, Elektron Tekh Gener Modul Rentgen Prib, 1, 1970, 6874 (in Russian). 16 1455. Some problems of sorption dynamics in the linear isotherm region with external-diffusion kinetics. (USSR) Different problems of sorption dynamics are solved in the linear isotherm region. Experimental verification of calculations is presented. E V Venitsianov et al, Zavodsk Lab, 37 (5), 1971,544-555 (in Russian). 18. GASEOUS ELECTRONICS 18 1456. Mean value energy of electrons ejected from atoms on ionization by electron impact. (USSR) Mean value of kinetic energy of electrons ejected from atoms on ionization by electron impact is calculated. L I Grechikhin and V V Kudryashov, Izv VUZ Fiz, No 9, 1970, 158-160
(in Russian). 18 1457. The work functions of z-iron, z-cobalt and z-manganese. (Germany) Films of z-iron, z-cobalt and z-manganese were deposited on quartz substrates by a double evaporation technique at pressures of less than
616
10-9 torr to overcome the problem of adequate degassing. The experimental tube used for photoelectric measurements is described. The tube was evacuated on a glass vacuum system with two mercury diffusion pumps and two liquid nitrogen traps. The background pressure was less than 2 × 10-l° torr after baking the system at 700°K and degassing the filaments at 2800°K. Preliminary work undertaken during a search for the best method of evaporation under ultrahigh vacuum was carried out with iron. Values of the work function of iron evaporated under pressures in the 10 -7 to 10-9 torr range varied between 4.0 and 4.7 eV, the lower values corresponding to the least successfully degassed samples. It is demonstrated that the double evaporation technique under described vacuum conditions allows excellent reproducibility in the work function determinations. The photoelectric work functions of films several tens of/~m thick were, as determined absolutely by a photoelectric technique using Fowler analysis of photoelectric yield results: z-Fe--4.714-0.02, z-Co--4.89 4-0.04, z-Mn--4.244-0.02 eV. G K Hall and C H B Mee, Phys Stat Sol (a), 5 (2), May 1971, 389-395. 18 1458. Temperature dependence of photostimulated electron emission from ionic crystals. (Germany) The temperature dependence of photoelectron emission from previously X-ray treated or UV-excited NaCI, KC1, KBr and KI single crystals has been studied in the region 100 to 420°K at various wavelengths in the visible range. A special cryostat was constructed for electron emission and simultaneous luminescence measurements. The cryostat was evacuated to 10-6 to 10 -7 torr by an oil diffusion pump. An electron multiplier tube served as electron detector. The observed thermal changes of the emission intensity and spectral distribution are attributed to chemisorption phenomena affecting the surface potential barrier of the samples. V Biehevin, Phys Stat Sol (a), 5 (2), May 1971, 519-523. 18 1459. Determination of strength of adhesion of an oxide coating to a cathode core, by the cut method. (USSR) The cut method for determination of the strength of adhesion of an oxide coating to the cathode core of a high-voltage modulator tube is studied. K I Bespalov and B A Palchevskiy, Elektron Tekh Gener Modul Rentgen Prib, 4, 1969, 53-58 (in Russian). 18 1460. Manufacture of thin-wall cathode cores. (USSR) A manufacturing technique for cylindrical cathode cores of nickel alloys with wall thickness of 0.04 to 0.1 mm, based on etching, is described. I L Gandelsman et al, Elektron Tekh Gener Modul Rentgen Prib, 4, 1969, 87-89 (in Russian). 18 1461. Hollow cathode effect in low-voltage Penning discharge. (USSR) The influence of gas pressure, dimensions of cathode cavity and magnetic field intensity on the volt-ampere characteristics of the discharge are investigated. It is shown that the discharge current can be two orders of magnitude higher than the current in a similar discharge with plane cathodes. Discharge systems with two hollow cathodes are shown to provide good stability of the discharge regime at high discharge currents. The results demonstrate the possibility of producing efficient and high-current discharge systems for electron sources based on the Penning discharge. V A Gruzdev and G G Vasileva, Sb Rab Aspir Tomsk Inst Radioelektr Elektron Tekh, 1, 1969, 262-269 (in Russian). 18 : 31 1462. Niobium alloys for high-temperatare cathode systems. (USSR) It is shown that niobium alloys have higher mechanical strength and workability than tantalum and that they can be used for manufacturing the high-temperature cathode assemblies of vacuum devices. E M Savitskiy et al, Elektron Tekh Elektron SVCh, 2, 1971, 93-98 (in
Russian). 18 : 31 1463. Utilization of nickel alloy with tungsten and zirconium as cathode core material for ultrahigh frequency diode 6D13D. (USSR) Cathodes with cores of nickel alloy with tungsten and zirconium in ultrahigh frequency diodes provide increased thermionic emission and a lowering of noise. A A Sokolov, Elektron Tekh Priemno Usilit Lampy, 2, 1970, 81-84 (in
Russian).
Russian). 16 1453. Sorption of water vapour by metals and alloys. (USSR) Methods for determination of sorption capability of the surfaces of copper, nickel, kovar, and iron for water vapour have been developed. Methods have also been developed for investigation of the desorption of water vapour from these materials during vacuum heat treatment. Water marked with tritium was used as a radioactive tracer. It is shown that the sorption capability of metal and alloy surfaces determined by this method depends on the cleaning procedures used on the surfaces examined. Sorption of water vapour from the samples after chemical polishing and heating in dry and moist hydrogen is investigated. The minimum quantity of water remains on the surface of metals after heating in hydrogen. After storage in air the samples subjected to chemical treatment and heating show an increase in sorption capability of 30 per cent. Storage of similar samples for 5 to 10 days in an atmosphere saturated with water vapour results in a two- to three-fold increase in the sorption capability. Yu M Kuzmin et al, Elektron Tekh Elektron SVCh, 2, 1971, 99-105
(in Russian). 16 1454. Interaction of non-evaporating getters with hydrogen and carbon monoxide. (USSR) Interaction of porous non-evaporating getters, of various compositions, with carbon monoxide and hydrogen, is investigated in the temperature range from room to 800°C. The dependences of the relative average sorption rates for carbon monoxide and hydrogen are presented, from which the optimum thermal regime of getter operation can be chosen for vacuum devices, taking account of requirements to residual gas composition in regard to the relative carbon monoxide to hydrogen concentrations. M F Boyarina, Elektron Tekh Gener Modul Rentgen Prib, 1, 1970, 6874 (in Russian). 16 1455. Some problems of sorption dynamics in the linear isotherm region with external-diffusion kinetics. (USSR) Different problems of sorption dynamics are solved in the linear isotherm region. Experimental verification of calculations is presented. E V Venitsianov et al, Zavodsk Lab, 37 (5), 1971,544-555 (in Russian). 18. GASEOUS ELECTRONICS 18 1456. Mean value energy of electrons ejected from atoms on ionization by electron impact. (USSR) Mean value of kinetic energy of electrons ejected from atoms on ionization by electron impact is calculated. L I Grechikhin and V V Kudryashov, Izv VUZ Fiz, No 9, 1970, 158-160
(in Russian). 18 1457. The work functions of z-iron, z-cobalt and z-manganese. (Germany) Films of z-iron, z-cobalt and z-manganese were deposited on quartz substrates by a double evaporation technique at pressures of less than
616
10-9 torr to overcome the problem of adequate degassing. The experimental tube used for photoelectric measurements is described. The tube was evacuated on a glass vacuum system with two mercury diffusion pumps and two liquid nitrogen traps. The background pressure was less than 2 × 10-l° torr after baking the system at 700°K and degassing the filaments at 2800°K. Preliminary work undertaken during a search for the best method of evaporation under ultrahigh vacuum was carried out with iron. Values of the work function of iron evaporated under pressures in the 10 -7 to 10-9 torr range varied between 4.0 and 4.7 eV, the lower values corresponding to the least successfully degassed samples. It is demonstrated that the double evaporation technique under described vacuum conditions allows excellent reproducibility in the work function determinations. The photoelectric work functions of films several tens of/~m thick were, as determined absolutely by a photoelectric technique using Fowler analysis of photoelectric yield results: z-Fe--4.714-0.02, z-Co--4.89 4-0.04, z-Mn--4.244-0.02 eV. G K Hall and C H B Mee, Phys Stat Sol (a), 5 (2), May 1971, 389-395. 18 1458. Temperature dependence of photostimulated electron emission from ionic crystals. (Germany) The temperature dependence of photoelectron emission from previously X-ray treated or UV-excited NaCI, KC1, KBr and KI single crystals has been studied in the region 100 to 420°K at various wavelengths in the visible range. A special cryostat was constructed for electron emission and simultaneous luminescence measurements. The cryostat was evacuated to 10-6 to 10 -7 torr by an oil diffusion pump. An electron multiplier tube served as electron detector. The observed thermal changes of the emission intensity and spectral distribution are attributed to chemisorption phenomena affecting the surface potential barrier of the samples. V Biehevin, Phys Stat Sol (a), 5 (2), May 1971, 519-523. 18 1459. Determination of strength of adhesion of an oxide coating to a cathode core, by the cut method. (USSR) The cut method for determination of the strength of adhesion of an oxide coating to the cathode core of a high-voltage modulator tube is studied. K I Bespalov and B A Palchevskiy, Elektron Tekh Gener Modul Rentgen Prib, 4, 1969, 53-58 (in Russian). 18 1460. Manufacture of thin-wall cathode cores. (USSR) A manufacturing technique for cylindrical cathode cores of nickel alloys with wall thickness of 0.04 to 0.1 mm, based on etching, is described. I L Gandelsman et al, Elektron Tekh Gener Modul Rentgen Prib, 4, 1969, 87-89 (in Russian). 18 1461. Hollow cathode effect in low-voltage Penning discharge. (USSR) The influence of gas pressure, dimensions of cathode cavity and magnetic field intensity on the volt-ampere characteristics of the discharge are investigated. It is shown that the discharge current can be two orders of magnitude higher than the current in a similar discharge with plane cathodes. Discharge systems with two hollow cathodes are shown to provide good stability of the discharge regime at high discharge currents. The results demonstrate the possibility of producing efficient and high-current discharge systems for electron sources based on the Penning discharge. V A Gruzdev and G G Vasileva, Sb Rab Aspir Tomsk Inst Radioelektr Elektron Tekh, 1, 1969, 262-269 (in Russian). 18 : 31 1462. Niobium alloys for high-temperatare cathode systems. (USSR) It is shown that niobium alloys have higher mechanical strength and workability than tantalum and that they can be used for manufacturing the high-temperature cathode assemblies of vacuum devices. E M Savitskiy et al, Elektron Tekh Elektron SVCh, 2, 1971, 93-98 (in
Russian). 18 : 31 1463. Utilization of nickel alloy with tungsten and zirconium as cathode core material for ultrahigh frequency diode 6D13D. (USSR) Cathodes with cores of nickel alloy with tungsten and zirconium in ultrahigh frequency diodes provide increased thermionic emission and a lowering of noise. A A Sokolov, Elektron Tekh Priemno Usilit Lampy, 2, 1970, 81-84 (in
Russian).