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Bulk negative resistance device operated in a relaxation mode
WORLD ABSTRACTS ON M I C R O E L E C T R O N I C S AND R E L I A B I L I T Y
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order have been obtained by extracting copper from GaAs in gallium, and have also been confirmed from literature data. Finally, indications have been found which show that copper diffuses much faster along dislocations than in dislocation-free bulk material. Bulk negative resistance device operated in a relaxation mode. C. LANZAand R. M. ESPOSITO, Solid-St. Electron. 12 (1969), p. 463. A bulk GaAs semiconductor negative resistance device has been operated in a relaxation mode analogous to tunnel diode operation. The output consists of a closelypacked train of narrow, high-voltage pulses. The circuit consists of an inductor in series with the parallel combination of the active device and the load resistor, driven by a low impedance generator. By shunting the device with a suitable load resistor, avalanche breakdown, which would normally occur, is prevented and the generated voltage pulses are impressed directly across the load. The circuit is constructed in a coaxial lines and operates without a cavity or other tuning elements. By driving this circuit with a pulse of about 100 nsec duration, an output pulse train having an amplitude of over 200 V (ten times Gunn threshold) was obtained across a 3000 f~ load. The output pulses were of about 1 nsec duration and spaced about 10 nsec apart. Since the pulse spacing varies with the amplitude of the drive voltage, pulse frequency modulation is possible. The ramifications of a time-variant characteristic caused by the formation of a travelling Gunn domain during part of the cycle are discussed. Anodic growth, dielectric breakdown and carrier transport in amorphous SiO~ films. C. R. FRITZSCHE,~¢. Phys. Chem. Solids. 30 (1969), p. 1885. Dielectric breakdown has been studied in anodically grown SiO 2 and compared with the growth conditions. It is found that avalanche multiplication of electrons and ionic conductivity are closely related. This supports the impact ionization theory of anodization recently published. An improved theory is given which supplies equations for efficiency of anodization, growth at constant current, and current decay at constant voltage in excellent agreement with experimental results. The effective mass ration of electrons to ions, the mean free time of the electrons, the mean time between ionizing collisions and the electron drift velocity are estimated from experimental data. Characterization control, and use of dielectric charge effects in silicon technology. J. R. SZEDONand R. M. HANDY,~. Vac. Sd. Technol. 6 (1), Jan.-Feb. (1969), p. 1. The charge behaviour of dielectric films on silicon is particularly important in device and integrated circuit technology because of surface defects. Models for ionic migration, fixed-interface charge, and injection trapping are reviewed for insulators used in silicon technology: thermally-grown silicon dioxide and chemical vapour-deposited silicon dioxide and silicon nitride. The distinctive characteristics of insulator charge related to these mechanisms are applied in the case of reactively sputtered SiO~ and TazOs. Ion migration and injectiontrapping behaviour are found under certain conditions of preparation for both materials. A degree of interface charge control is indicated in the study of sputtered silicon dioxide. More work is needed to establish the future utility of these materials. Dielectric materials in semiconductor devices. T. L. CHU,J. Vac. Sc~. Technol. 6 (1), Jam-Feb. (1969), p. 25. Dielectric films are used extensively in semiconductor technology for masking against the diffusion of dopants into semiconductors, fabrication of active and passive components, electrical isolation between components, and surface passivation of devices. Silica is the most widely used dielectric in silicon devices at present, the preparation and properties of silica films are reviewed. However, silica is structurally porous, resulting in the high permeability of silica films toward impurities and the migration of impurity ions in silica films. Considerable efforts have been made to investigate other dielectrics during the past few years. The preparation and properties of several important dielectric films are discussed. Silicon nitride and aluminium oxide have been shown to be superior to silica in several respects. Various silica-silicon nitride and silica-alumina combinations have provided new and improved devices. Adhesion mechanism of gold-underlayer film combinations to oxide substrates. K. E. HAQ et al., .7. Vac. Sd. Technol. 6 (1), Jam-Feb. (1969), p. 148. The adhesion between glass or oxidized Si substrates and evaporated gold films in combination with an adherent intermediate layer of Ta, Si, Ge, or Cr has been investigated. The experimental results regarding changes of adhesion as a function of the relative thickness of the Au and underlayer films as well as time, environment, and treatment
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order have been obtained by extracting copper from GaAs in gallium, and have also been confirmed from literature data. Finally, indications have been found which show that copper diffuses much faster along dislocations than in dislocation-free bulk material. Bulk negative resistance device operated in a relaxation mode. C. LANZAand R. M. ESPOSITO, Solid-St. Electron. 12 (1969), p. 463. A bulk GaAs semiconductor negative resistance device has been operated in a relaxation mode analogous to tunnel diode operation. The output consists of a closelypacked train of narrow, high-voltage pulses. The circuit consists of an inductor in series with the parallel combination of the active device and the load resistor, driven by a low impedance generator. By shunting the device with a suitable load resistor, avalanche breakdown, which would normally occur, is prevented and the generated voltage pulses are impressed directly across the load. The circuit is constructed in a coaxial lines and operates without a cavity or other tuning elements. By driving this circuit with a pulse of about 100 nsec duration, an output pulse train having an amplitude of over 200 V (ten times Gunn threshold) was obtained across a 3000 f~ load. The output pulses were of about 1 nsec duration and spaced about 10 nsec apart. Since the pulse spacing varies with the amplitude of the drive voltage, pulse frequency modulation is possible. The ramifications of a time-variant characteristic caused by the formation of a travelling Gunn domain during part of the cycle are discussed. Anodic growth, dielectric breakdown and carrier transport in amorphous SiO~ films. C. R. FRITZSCHE,~¢. Phys. Chem. Solids. 30 (1969), p. 1885. Dielectric breakdown has been studied in anodically grown SiO 2 and compared with the growth conditions. It is found that avalanche multiplication of electrons and ionic conductivity are closely related. This supports the impact ionization theory of anodization recently published. An improved theory is given which supplies equations for efficiency of anodization, growth at constant current, and current decay at constant voltage in excellent agreement with experimental results. The effective mass ration of electrons to ions, the mean free time of the electrons, the mean time between ionizing collisions and the electron drift velocity are estimated from experimental data. Characterization control, and use of dielectric charge effects in silicon technology. J. R. SZEDONand R. M. HANDY,~. Vac. Sd. Technol. 6 (1), Jan.-Feb. (1969), p. 1. The charge behaviour of dielectric films on silicon is particularly important in device and integrated circuit technology because of surface defects. Models for ionic migration, fixed-interface charge, and injection trapping are reviewed for insulators used in silicon technology: thermally-grown silicon dioxide and chemical vapour-deposited silicon dioxide and silicon nitride. The distinctive characteristics of insulator charge related to these mechanisms are applied in the case of reactively sputtered SiO~ and TazOs. Ion migration and injectiontrapping behaviour are found under certain conditions of preparation for both materials. A degree of interface charge control is indicated in the study of sputtered silicon dioxide. More work is needed to establish the future utility of these materials. Dielectric materials in semiconductor devices. T. L. CHU,J. Vac. Sc~. Technol. 6 (1), Jam-Feb. (1969), p. 25. Dielectric films are used extensively in semiconductor technology for masking against the diffusion of dopants into semiconductors, fabrication of active and passive components, electrical isolation between components, and surface passivation of devices. Silica is the most widely used dielectric in silicon devices at present, the preparation and properties of silica films are reviewed. However, silica is structurally porous, resulting in the high permeability of silica films toward impurities and the migration of impurity ions in silica films. Considerable efforts have been made to investigate other dielectrics during the past few years. The preparation and properties of several important dielectric films are discussed. Silicon nitride and aluminium oxide have been shown to be superior to silica in several respects. Various silica-silicon nitride and silica-alumina combinations have provided new and improved devices. Adhesion mechanism of gold-underlayer film combinations to oxide substrates. K. E. HAQ et al., .7. Vac. Sd. Technol. 6 (1), Jam-Feb. (1969), p. 148. The adhesion between glass or oxidized Si substrates and evaporated gold films in combination with an adherent intermediate layer of Ta, Si, Ge, or Cr has been investigated. The experimental results regarding changes of adhesion as a function of the relative thickness of the Au and underlayer films as well as time, environment, and treatment