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Analysis of static and dynamic characteristics in v.i.l.
World Abstracts on Microelectronics and Reliability
One chip controls keyboard and display. LORNE TROTTIER and BRANKO MATIC. Electronics p. 125 (11 May 1978). Device simplifies microprocessor interface to alphanumeric displays. Managing the flow of data is easy with programmable multiplexer. DAVE WYLAND. Electronics p. 132 (11 May 1978). Device dedicated to data management has diode-
231
fuse array that may be programmed with standard PROM techniques to set up bit flow.
Single-chip microcomputer expands its memory. HAROLD W. DOZIERand Robert S. GREEN. Electronics p. 105 (11 May 1978). Over 4 kilobytes of program storage includes 64 bytes of executable RAM to extend the one-chipper into more complex applications.
7. SEMICONDUCTOR INTEGRATED CIRCUITS, DEVICES A N D MATERIALS The role of distributed parameters in the analysis of technological processes of semiconductor technique. W. HEINZE and J. LUDWIG. Nachrichtentechnik Electronik 28, (5) 184 (1978) (in German). Owing to close tolerances admitted for dimensions and the concentration of differently doped regions, distributed parameters must at any rate be taken into account in analysing technological processes in semiconductor technique, as is illustrated by the inverse voltage of p+ pn ÷ power diodes. Their effect can quantitatively be determined by means of their distribution curves if they can be measured as concentrated parameters, or by stating the extent to which measurable parameters depending on them may be modified.
A model of charge injection at metal-insulator contacts. I. CHEN. Solid St. Commun. 26, 359 (1978). A phenomenological model of charge carrier injection at metal-insulator contacts is proposed to quantify the injection property of such contacts, especially of non-Ohmic ones. The model contains two parameters: one is the injection current G at a given field, and the other is the field-dependence power p of the injection. It is shown that the values of G and p for a given contact can be determined from the results of step-voltage experiments. When applied to the data on Au-As2Se3 contact, it is found that the injection current is G ~ 10- 6 A cm- 2 at a field of l0 s V cm- 1, and the field dependence is approximately quadratic, p ~ 2. In addition, the field-dependence and the thickness-independence of the peak current can be explained.
Energy spectrum particularities of gapless semiconductors with impurities. V. K. DUGAEVand P. P. PETROV. Solid St. Commun. 26, 303 (1978). At the T-matrix approximation the possibility of dielectric gap formation in single-particle spectrum of gapless semiconductors in the presence of impurity is shown. Value of the gap depends upon impurity concentration and impurity level position.
For a 001-stress along a (100)-surface one finds that (i) the stress induced subband splitting is a function of the electron density, and (ii) the splitting E1 - E 0 within a subband system depends on the applied stress.
Analysis of static and dynamic characteristics in v.i.I. SHUICHI KATO, OSAMU TOMISAWA, YASUTAKA HORIBA and TAKAO NAKANO. Solid-St. Electron Devices 2, (3) 83 (May 1978). After a survey of the electrical characteristics for vertical injection logic (v.i.l.) structure compared with the conventional i.i.l, structure, static characteristics and dynamic behaviour for the v.i.l, structure are analysed by using a simplified one-dimensional model, and experimental verifications are carried out. The analysis reveals that the minimum propagation delay time is determined by the cutoff frequency of the n-p-n transistor and the effective lifetime of holes injected into the epitaxial layer from the base. The bottom injector in the v.i.1, structure reduces the effective lifetime of the holes, which results in improved minimum propagation delay times. In addition, the improvement in the minimum propagation delay times due to a reduction in the effective lifetime is more pronounced when the cutoff frequency is higher. Experimental results show that the minimum progation delay time for v.i.l, is improved by a factor of 1.6, as predicted from the analysis.
Experimental comparison of lifetime-measurement techniques for m.o.s, capacitors. C. MORANDI and G. SPADINI. Solid-St. Electron Devices 2, (3) 69 (May 1978). Three techniques commonly used to determine lifetime in m.o.s. capacitors are compared experimentally and very good agreement is found. It is shown that, in favourable circumstances, the combined use of the three may help to localise the active defect in the forbidden gap. Finally, some experimental results obtained with two of the techniques over a wide temperature range are discussed.
The assessment of the formal semiconductor device theory. Conductivity increase of amorphous Si and Ge by Mn. T. SHIMIZU, M. KUMEDA, I. WATANABEand K, KAMONO. Solid St. Commun. 26, 445 (1978). Amorphous Si and Ge are doped with Mn by co-sputtering. The electrical conductivity is increased by as much as a factor of 10° ~ 107 in some cases by the addition of several at % Mn. The temperature dependence of the conductivity shows the variable range hopping conduction for both samples with and without Mn. The results can be interpreted by the presence of two conduction processes; the variable range hopping through dangling bonds and that through Mn sites.
Hartree calculations for n-inversion layers on stressed silicon surfaces. H. TEWS. Solid St. Commun. 26, 349 (1978). The energy splittings and occupation number densities in n-type inversion layers are estimated in a Hartree calculation with a parametrized exponential potential, Good agreement with experiment is obtained for low temperatures and for electron concentrations 1 x 1012cm -2 =< Ns =< 1 x 1013 cm -2. On the basis of these calculations the influence of uniaxial stress is considered.
A. CHIABRERA,R. DELF1NO, D. PONTA, G. VERNAZZAand R. VIVIANI. Alta Frequenza XLVI1, (5) 265 (March 1978). The paper gives a contribution to the assessment of the formal semiconductor device theory. The analysis of an extrinsic semiconductor region, which is bounded by junctions, ohmic contacts and interfaces with dielectrics, is performed, taking into account doping gradient effects, nonuniform spatial distribution of minority carrier lifetimes and surface recombination velocities. The general properties of the network matrix that models the semiconductor regions are found. The generation-recombination currents in the junctions and the voltage drops in the quasi-neutral region are evaluated. The approach is suitable to implement the model in CAD programs, provided that the region overall parameters are experimentally identified on real devices.
Fixed-interface.-eharge
model for isotype heterojunctions.
D, DELAGEBEAUDEUFand M. LESCROEL Solid-St. Electron Devices 2, (3) 91 (May 1978). Numerous anomalies have been observed in the electrical characteristics of isotype n-Ge/n-GaAs heterojunctions which cannot be explained
One chip controls keyboard and display. LORNE TROTTIER and BRANKO MATIC. Electronics p. 125 (11 May 1978). Device simplifies microprocessor interface to alphanumeric displays. Managing the flow of data is easy with programmable multiplexer. DAVE WYLAND. Electronics p. 132 (11 May 1978). Device dedicated to data management has diode-
231
fuse array that may be programmed with standard PROM techniques to set up bit flow.
Single-chip microcomputer expands its memory. HAROLD W. DOZIERand Robert S. GREEN. Electronics p. 105 (11 May 1978). Over 4 kilobytes of program storage includes 64 bytes of executable RAM to extend the one-chipper into more complex applications.
7. SEMICONDUCTOR INTEGRATED CIRCUITS, DEVICES A N D MATERIALS The role of distributed parameters in the analysis of technological processes of semiconductor technique. W. HEINZE and J. LUDWIG. Nachrichtentechnik Electronik 28, (5) 184 (1978) (in German). Owing to close tolerances admitted for dimensions and the concentration of differently doped regions, distributed parameters must at any rate be taken into account in analysing technological processes in semiconductor technique, as is illustrated by the inverse voltage of p+ pn ÷ power diodes. Their effect can quantitatively be determined by means of their distribution curves if they can be measured as concentrated parameters, or by stating the extent to which measurable parameters depending on them may be modified.
A model of charge injection at metal-insulator contacts. I. CHEN. Solid St. Commun. 26, 359 (1978). A phenomenological model of charge carrier injection at metal-insulator contacts is proposed to quantify the injection property of such contacts, especially of non-Ohmic ones. The model contains two parameters: one is the injection current G at a given field, and the other is the field-dependence power p of the injection. It is shown that the values of G and p for a given contact can be determined from the results of step-voltage experiments. When applied to the data on Au-As2Se3 contact, it is found that the injection current is G ~ 10- 6 A cm- 2 at a field of l0 s V cm- 1, and the field dependence is approximately quadratic, p ~ 2. In addition, the field-dependence and the thickness-independence of the peak current can be explained.
Energy spectrum particularities of gapless semiconductors with impurities. V. K. DUGAEVand P. P. PETROV. Solid St. Commun. 26, 303 (1978). At the T-matrix approximation the possibility of dielectric gap formation in single-particle spectrum of gapless semiconductors in the presence of impurity is shown. Value of the gap depends upon impurity concentration and impurity level position.
For a 001-stress along a (100)-surface one finds that (i) the stress induced subband splitting is a function of the electron density, and (ii) the splitting E1 - E 0 within a subband system depends on the applied stress.
Analysis of static and dynamic characteristics in v.i.I. SHUICHI KATO, OSAMU TOMISAWA, YASUTAKA HORIBA and TAKAO NAKANO. Solid-St. Electron Devices 2, (3) 83 (May 1978). After a survey of the electrical characteristics for vertical injection logic (v.i.l.) structure compared with the conventional i.i.l, structure, static characteristics and dynamic behaviour for the v.i.l, structure are analysed by using a simplified one-dimensional model, and experimental verifications are carried out. The analysis reveals that the minimum propagation delay time is determined by the cutoff frequency of the n-p-n transistor and the effective lifetime of holes injected into the epitaxial layer from the base. The bottom injector in the v.i.1, structure reduces the effective lifetime of the holes, which results in improved minimum propagation delay times. In addition, the improvement in the minimum propagation delay times due to a reduction in the effective lifetime is more pronounced when the cutoff frequency is higher. Experimental results show that the minimum progation delay time for v.i.l, is improved by a factor of 1.6, as predicted from the analysis.
Experimental comparison of lifetime-measurement techniques for m.o.s, capacitors. C. MORANDI and G. SPADINI. Solid-St. Electron Devices 2, (3) 69 (May 1978). Three techniques commonly used to determine lifetime in m.o.s. capacitors are compared experimentally and very good agreement is found. It is shown that, in favourable circumstances, the combined use of the three may help to localise the active defect in the forbidden gap. Finally, some experimental results obtained with two of the techniques over a wide temperature range are discussed.
The assessment of the formal semiconductor device theory. Conductivity increase of amorphous Si and Ge by Mn. T. SHIMIZU, M. KUMEDA, I. WATANABEand K, KAMONO. Solid St. Commun. 26, 445 (1978). Amorphous Si and Ge are doped with Mn by co-sputtering. The electrical conductivity is increased by as much as a factor of 10° ~ 107 in some cases by the addition of several at % Mn. The temperature dependence of the conductivity shows the variable range hopping conduction for both samples with and without Mn. The results can be interpreted by the presence of two conduction processes; the variable range hopping through dangling bonds and that through Mn sites.
Hartree calculations for n-inversion layers on stressed silicon surfaces. H. TEWS. Solid St. Commun. 26, 349 (1978). The energy splittings and occupation number densities in n-type inversion layers are estimated in a Hartree calculation with a parametrized exponential potential, Good agreement with experiment is obtained for low temperatures and for electron concentrations 1 x 1012cm -2 =< Ns =< 1 x 1013 cm -2. On the basis of these calculations the influence of uniaxial stress is considered.
A. CHIABRERA,R. DELF1NO, D. PONTA, G. VERNAZZAand R. VIVIANI. Alta Frequenza XLVI1, (5) 265 (March 1978). The paper gives a contribution to the assessment of the formal semiconductor device theory. The analysis of an extrinsic semiconductor region, which is bounded by junctions, ohmic contacts and interfaces with dielectrics, is performed, taking into account doping gradient effects, nonuniform spatial distribution of minority carrier lifetimes and surface recombination velocities. The general properties of the network matrix that models the semiconductor regions are found. The generation-recombination currents in the junctions and the voltage drops in the quasi-neutral region are evaluated. The approach is suitable to implement the model in CAD programs, provided that the region overall parameters are experimentally identified on real devices.
Fixed-interface.-eharge
model for isotype heterojunctions.
D, DELAGEBEAUDEUFand M. LESCROEL Solid-St. Electron Devices 2, (3) 91 (May 1978). Numerous anomalies have been observed in the electrical characteristics of isotype n-Ge/n-GaAs heterojunctions which cannot be explained