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On the mechanism of indirect band to band recombination in germanium electron-hole drops
379
World Abstracts on Microelectronics and Reliability
to map the stepwise temperature distribution of a heated surface. From the color-digitized thermograms the chip temperature rise over the ambient air can be computed with the aid of thermocouple measurements. The color thermograms also help evaluate the thermal resistances of the chip and the ceramic carrier, which are used in the thermoelectric analogical analysis of steady-state heat flow from the chip to the surrounding air under free convection condition. The chip temperature rise as evaluated by the thermoelectric analysis checks reasonably well with the infrared and thermocouple measurements. These two methods have their respective advantages in determining the temperature of integrated-circuit chips.
resistors and CMOS transistor arrays as the circuit elements. The CMOS array can be used to produce either an integrator or an inverting amplifier depending on the power supply voltage. The design equations are very simple and with some modifications, the filter can be used to realize any biquadratic voltage transfer function in a straight-forward manner.
Eight-bit microprocessor aims at control applications. W. E. WICKES. Electronics p. 101 (June 1976). LSI chip uses single power supply, interfaces with any 8-bit bus-oriented TTL-compatible peripherals. Determination of temperature of integrated-circuit chips in hybrid packaging. ER-YUNG YU. IEEE Trans. Parts, Hybrids, and Packaying. PHP-12 (2), 139 (1976). This paper describes an infrared technique and an analogical method to determine the maximum temperature of a beam-leaded integrated-circuit chip, mounted on a ceramic carrier. The infrared technique employs a color thermogram camera 7. S E M I C O N D U C T O R
INTEGRATED
Processor family specialises in dedicated control. ALAN WEISSBERGER, JACK IRWIN and Soo NAM KIM. Electronics p. 84 (July 1976). Just one or two chips contain all the microcontroller elements needed in low-speed, highvolume applications like appliances or credit checkers. CIRCUITS,
The configuration-based approach for 3d impurities in palladium and platinum. GWYN WILLIAMS. Solid-State Commun. 19, 821 (1976). It is suggested that the magnitude and variation of the characteristic temperature associated with 1st transition series impurities in Pd and Pt could be interpreted within the framework of configurational phase stability criteria. Td-pyramids in silicon epitaxial layers. H. AHARONI. Vacuum 26 (4/5), 181 (1976). The external shapes of tripyramid defects are summarized and typical shapes, deviations from the typical, and the interactions between tripyramids and stacking faults are described. Two basic types of typical tri-pyramids were observed, one with a single peak, and the other with three peaks. The symmetry of the typical tri-pyramids is three-fold. The angle between the apexes of the three pyramids composing the tri-pyramid is 120". Each of the pyramids composing the tri-pyramid is a single crystal but with crystallographic orientation different from that of the rest of the layer. The deviations consist of amputated tri-pyramids, bi-pyramids and monopyramids, none of which are symmetrical. The layer surface nearest the tri-pyramide is not planar, but distorted. Dash etch was used to reveal stacking faults interacting concentrically with typical tri-pyramids. The dimensions of the tri-pyramid and the stacking fault are proportional to the epitaxial layer thickness. Photographs of interactions among tri-pyramids and stacking faults are obtained by using S.E.M. to obtain high resolution, which reveals finer details in higher magnifications. Traces of SiC or SiO 2 or other foreign materials, together with some basic mechanism, are probably responsible for tri-pyramid formation, They can be prevented by proper treatment of the silicon substrate prior to the layer growth. Photo-thermal probing of Si-SiO2 surface centres--ll. Experiment. R. F. PIERRET and B. B. ROESNER. Solid-State Electron. 19, 593 (1976). The results of photo-thermal probing measurements are presented and interpreted to characterize the Si SiO 2 surface center photoresponse and to provide information relevant to the evaluation of existing surface state models. Data is first presented to indisputably confirm the facts that surface center photoemission had indeed been observed and that the photoresponse could be isolated from competing relaxation mechanisms. The subsequent presentation is devoted primarily to an examination and analysis of photovoltage vs time data characterizing the surface center response. From the analysis it is concluded that two distinct types of surface centers are quasi-continuously distributed in energy over the central portion of the Si band gap, with both types of states
DEVICES
AND
MATERIALS
acting as if they were positioned right at the S-SiO 2 interface. The feature distinguishing the two types of states, referred to as A-states and B-states, is widely different photocapture cross section at any given band gap energy measured photocapture cross sections being on the order of 10-19cm2 and 10-2°cm 2 and 102 for A- and B-states, respectively. B-states, which exhibit the longer photorelaxation time constant, dominate the response in the upper portion of the band gap, while A-states dominate the response below approximately E v + 0.3 eV. Finally, the photocapture cross section of each type of state was found to increase systematically toward the band edges due to a Lucovsky-type energy dependence. Doped silicon oxide as diffusion source. A. CHECIELEWSKA and J. KOSZUR. Electron. Tech. 8 (2), 115 (1975). The paper describes a method of preparing doped silicon oxide layers using the reaction of tetraetoxysilane and phosphorus oxichloride oxidation at 400°C. The layers were examined as possible sources of phosphorus diffusion to silicon. A mathematical model of diffusion in Si-SiO 2 system has been developed. The results of computer calculations of impurity distribution in SiO2 layer have been compared with experimental data and the validity of the assumptions used in the model has been discussed.
On the mechanism of indirect band to band recombination i n germanium electron-hole drops. R. W. MARTIN. SolidState Commun. 19, 373 (1976). The line shape of all three recombination lines of electron-hole drops has been analyzed. The appropriate transition matrix element for the TA-line was found to depend linearly on the momentum of the hole only. The TO-matrix element can be visualized as a mixture of the matrix elements for LA- and TAphonons. Influence of low lifetime regions on recombination in high lifetime regions of semiconductors. B. JAYANT BALIGA and MANUEL L. TORREt
World Abstracts on Microelectronics and Reliability
to map the stepwise temperature distribution of a heated surface. From the color-digitized thermograms the chip temperature rise over the ambient air can be computed with the aid of thermocouple measurements. The color thermograms also help evaluate the thermal resistances of the chip and the ceramic carrier, which are used in the thermoelectric analogical analysis of steady-state heat flow from the chip to the surrounding air under free convection condition. The chip temperature rise as evaluated by the thermoelectric analysis checks reasonably well with the infrared and thermocouple measurements. These two methods have their respective advantages in determining the temperature of integrated-circuit chips.
resistors and CMOS transistor arrays as the circuit elements. The CMOS array can be used to produce either an integrator or an inverting amplifier depending on the power supply voltage. The design equations are very simple and with some modifications, the filter can be used to realize any biquadratic voltage transfer function in a straight-forward manner.
Eight-bit microprocessor aims at control applications. W. E. WICKES. Electronics p. 101 (June 1976). LSI chip uses single power supply, interfaces with any 8-bit bus-oriented TTL-compatible peripherals. Determination of temperature of integrated-circuit chips in hybrid packaging. ER-YUNG YU. IEEE Trans. Parts, Hybrids, and Packaying. PHP-12 (2), 139 (1976). This paper describes an infrared technique and an analogical method to determine the maximum temperature of a beam-leaded integrated-circuit chip, mounted on a ceramic carrier. The infrared technique employs a color thermogram camera 7. S E M I C O N D U C T O R
INTEGRATED
Processor family specialises in dedicated control. ALAN WEISSBERGER, JACK IRWIN and Soo NAM KIM. Electronics p. 84 (July 1976). Just one or two chips contain all the microcontroller elements needed in low-speed, highvolume applications like appliances or credit checkers. CIRCUITS,
The configuration-based approach for 3d impurities in palladium and platinum. GWYN WILLIAMS. Solid-State Commun. 19, 821 (1976). It is suggested that the magnitude and variation of the characteristic temperature associated with 1st transition series impurities in Pd and Pt could be interpreted within the framework of configurational phase stability criteria. Td-pyramids in silicon epitaxial layers. H. AHARONI. Vacuum 26 (4/5), 181 (1976). The external shapes of tripyramid defects are summarized and typical shapes, deviations from the typical, and the interactions between tripyramids and stacking faults are described. Two basic types of typical tri-pyramids were observed, one with a single peak, and the other with three peaks. The symmetry of the typical tri-pyramids is three-fold. The angle between the apexes of the three pyramids composing the tri-pyramid is 120". Each of the pyramids composing the tri-pyramid is a single crystal but with crystallographic orientation different from that of the rest of the layer. The deviations consist of amputated tri-pyramids, bi-pyramids and monopyramids, none of which are symmetrical. The layer surface nearest the tri-pyramide is not planar, but distorted. Dash etch was used to reveal stacking faults interacting concentrically with typical tri-pyramids. The dimensions of the tri-pyramid and the stacking fault are proportional to the epitaxial layer thickness. Photographs of interactions among tri-pyramids and stacking faults are obtained by using S.E.M. to obtain high resolution, which reveals finer details in higher magnifications. Traces of SiC or SiO 2 or other foreign materials, together with some basic mechanism, are probably responsible for tri-pyramid formation, They can be prevented by proper treatment of the silicon substrate prior to the layer growth. Photo-thermal probing of Si-SiO2 surface centres--ll. Experiment. R. F. PIERRET and B. B. ROESNER. Solid-State Electron. 19, 593 (1976). The results of photo-thermal probing measurements are presented and interpreted to characterize the Si SiO 2 surface center photoresponse and to provide information relevant to the evaluation of existing surface state models. Data is first presented to indisputably confirm the facts that surface center photoemission had indeed been observed and that the photoresponse could be isolated from competing relaxation mechanisms. The subsequent presentation is devoted primarily to an examination and analysis of photovoltage vs time data characterizing the surface center response. From the analysis it is concluded that two distinct types of surface centers are quasi-continuously distributed in energy over the central portion of the Si band gap, with both types of states
DEVICES
AND
MATERIALS
acting as if they were positioned right at the S-SiO 2 interface. The feature distinguishing the two types of states, referred to as A-states and B-states, is widely different photocapture cross section at any given band gap energy measured photocapture cross sections being on the order of 10-19cm2 and 10-2°cm 2 and 102 for A- and B-states, respectively. B-states, which exhibit the longer photorelaxation time constant, dominate the response in the upper portion of the band gap, while A-states dominate the response below approximately E v + 0.3 eV. Finally, the photocapture cross section of each type of state was found to increase systematically toward the band edges due to a Lucovsky-type energy dependence. Doped silicon oxide as diffusion source. A. CHECIELEWSKA and J. KOSZUR. Electron. Tech. 8 (2), 115 (1975). The paper describes a method of preparing doped silicon oxide layers using the reaction of tetraetoxysilane and phosphorus oxichloride oxidation at 400°C. The layers were examined as possible sources of phosphorus diffusion to silicon. A mathematical model of diffusion in Si-SiO 2 system has been developed. The results of computer calculations of impurity distribution in SiO2 layer have been compared with experimental data and the validity of the assumptions used in the model has been discussed.
On the mechanism of indirect band to band recombination i n germanium electron-hole drops. R. W. MARTIN. SolidState Commun. 19, 373 (1976). The line shape of all three recombination lines of electron-hole drops has been analyzed. The appropriate transition matrix element for the TA-line was found to depend linearly on the momentum of the hole only. The TO-matrix element can be visualized as a mixture of the matrix elements for LA- and TAphonons. Influence of low lifetime regions on recombination in high lifetime regions of semiconductors. B. JAYANT BALIGA and MANUEL L. TORREt