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CMOS comes of age
World Abstracts on Microelectronics and Reliability
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5. MICROELECTRONICS--DESIGN AND CONSTRUCTION A modular method for LSI circuits testing. G. JASINEVITCHENE, B. BURGIS and E. METSAEV. Proc. CNET Conference on Reliability and Maintainability, Tregastel, France, p. 1 (8-12 September 1980). A method for large-scale integrated (LSI) circuits testing is presented which enables to investigate LSI circuit as a composition of several simple parts. There are three stages of this method : (1) circuit partitioning into modules, (2) test generation for each module, (3) the circuit test compilation from test sets for modules. The problems of these stages have been revealed and a reasonable solution has been suggested. A new dielectric isolation method using porous silicon. KAZOO IMAI. Solid-St. Electron. 24, 159 (1981). A new dielectric isolation technology is proposed. In the new structure, single crystalline Si islands are separated from the silicon substrate by oxidized porous silicon. It is based on the following characteristics of the porous silicon oxide formation: (l) p-type Si is more easily changed to porous silicon than n-type Si; (2) porous silicon is formed along the anodic reaction current flow line; (3) the change in volume of porous silicon after oxidation is relatively small; (4) thick porous silicon films (10llm) can be obtained easily. In this method, a p-type isolated layer is obtained by proton implantation used for an n-type layer formation. Lateral p-n junctions fabricated in such isolated silicon layers show lower leakage current than those reported in SOS technology.
Thermal stress analysis of composite eneapsulants with a spherical adhesive interface. A. S. JORDAN and G. W. BERKSTRESSER. Microelectron. Reliab. 20, 495 (1980). Semiconductor devices packaged in a rigid epoxy often utilize an internal compliant coating to minimize stresses
transferred to the chip. Thermal stress analysis of such a composite encapsulating system with a spherical adhesive interface has been performed. The compliant layer encounters the highest tensile stress level upon cooling from the epoxy molding temperature due to the mismatch of thermal expansion coefficients and elastic properties within the composite. Indeed, this stress may readily exceed the tensile strength of the inner coating resulting in its fracture. In order to facilitate a systematic search for compatible plastics which assure package integrity, a useful figure of merit which is suggested by the analysis, the composite modulus, has been devised. A review of two dimensional long channel MOSFET modeling. UMESH KUMAR. Microelectron. Reliab. 20, 585 (1980). To obtain the necessary basic insight into the behaviour of MOSFET needed for device design and optimization, the basic equations must describe the two dimensional characteristics of the device. The increased power and availability of modern digital computers makes such an approach to derive most general and exact solutions feasible. A comprehensive review is made of the attempts at 2d MOSFET modeling. A two-dimensional placement algorithm for the layout of electronic circuits. HARIOM GUPTA and JAYDEV SHARIVlA. Microelectron. Reliab. 20, 323 (1980). A method is developed for the optimal placement of components or subsystems to specific locations on the backboard. The objective is to minimize the number of etches passing through unit space on the board (interconnection density) and the number of holes. This avoids the congested area on the board, makes a proper distribution of wiring and reduces the stray capacitances. X - Y coordinate wiring has been used.
6. MICROELECTRONICS--COMPONENTS, SYSTEMS AND EQUIPMENTS CMOS uncommitted logic arrays are part-digital, partanalog. DAN YODER, JR. Electronics, p. 163 (13 January 1981). Basic cells for logic and specialized analog quadrants serve many applications; software customizes metalization and contacts.
Fast 16-K static RAM tolerates faults. BRUCE LEBOSS. Electronics, p. 196 (13 January 1981). 55-ns RAM is made with double-polysilicon process, has three redundant rows to raise yield and polyimide to fight alphas. VLSI tester is highly modular. RICHARD W. COMERFORD. Electronics, p. 187 (13 January 1981). 40-MHz general-
purpose semiconductor test system, the first of a series, eases investment through modular hardware, software. CMOS comes of age. DAVID FULLAGAR. IEEE Spectrum, p. 24 (December 1980). Complementary metal-oxide semiconductors--at one time a "stepchild"--is leading the way in digital and analog circuits.
Charge build-up in MOS system under ionizing radiation. SWARAJ SRIVASTAVA,G. P. SRIVASTAVAand B. R. SINGH. Microelectron. Reliab. 20, 529 (1980). This paper reports the results on the charge formation in MOS system under ionizing radiation. The roles of different gate metals and oxide growth conditions are discussed.
7. SEMICONDUCTOR INTEGRATED CIRCUITS, DEVICES AND MATERIALS The diffusion of hot electrons across a semiconductor base. B. K. RIDLEY. Solid-St. Electron. 24, 147 (1981). A theoretical description of the diffusion of electrons injected at energies much greater than optical or inter-valley phonon energies into a semiconductor and their collection over a semiconductor-semiconductor barrier is given. Energy loss is assumed to be solely by collisions with high frequency phonons via the deformation-potential interaction, and specific solutions of the Boltzmann equation are obtained for a delta-function injection and parabolic bands. Application of the theory to silicon gives useful current-transfer ratio base widths of 150A and less, and the effect of quantummechanical reflection is found to be relatively unimportant. The results for the current-transfer ratios are dependent on
non-parabolicity in the conduction band of silicon, and a model for the latter is described. An effective attenuation length of 360A is predicted for silicon. The distribution function for hot electrons should reflect the variation of density-of-states in the conduction band.
Minority carrier injection and storage into a heavily doped emitter. Approximate solution for auger recombination. W. P. DUMKE. Solid-St. Electron. 24, 155 (1981). An analytic solution for the injected carrier distribution in a linearly graded, heavily doped region is given in terms of Hermite polynomials. The properties of this distribution are compared with those for the more usual diffusion length solution. An expression is given for the effect on high frequency
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5. MICROELECTRONICS--DESIGN AND CONSTRUCTION A modular method for LSI circuits testing. G. JASINEVITCHENE, B. BURGIS and E. METSAEV. Proc. CNET Conference on Reliability and Maintainability, Tregastel, France, p. 1 (8-12 September 1980). A method for large-scale integrated (LSI) circuits testing is presented which enables to investigate LSI circuit as a composition of several simple parts. There are three stages of this method : (1) circuit partitioning into modules, (2) test generation for each module, (3) the circuit test compilation from test sets for modules. The problems of these stages have been revealed and a reasonable solution has been suggested. A new dielectric isolation method using porous silicon. KAZOO IMAI. Solid-St. Electron. 24, 159 (1981). A new dielectric isolation technology is proposed. In the new structure, single crystalline Si islands are separated from the silicon substrate by oxidized porous silicon. It is based on the following characteristics of the porous silicon oxide formation: (l) p-type Si is more easily changed to porous silicon than n-type Si; (2) porous silicon is formed along the anodic reaction current flow line; (3) the change in volume of porous silicon after oxidation is relatively small; (4) thick porous silicon films (10llm) can be obtained easily. In this method, a p-type isolated layer is obtained by proton implantation used for an n-type layer formation. Lateral p-n junctions fabricated in such isolated silicon layers show lower leakage current than those reported in SOS technology.
Thermal stress analysis of composite eneapsulants with a spherical adhesive interface. A. S. JORDAN and G. W. BERKSTRESSER. Microelectron. Reliab. 20, 495 (1980). Semiconductor devices packaged in a rigid epoxy often utilize an internal compliant coating to minimize stresses
transferred to the chip. Thermal stress analysis of such a composite encapsulating system with a spherical adhesive interface has been performed. The compliant layer encounters the highest tensile stress level upon cooling from the epoxy molding temperature due to the mismatch of thermal expansion coefficients and elastic properties within the composite. Indeed, this stress may readily exceed the tensile strength of the inner coating resulting in its fracture. In order to facilitate a systematic search for compatible plastics which assure package integrity, a useful figure of merit which is suggested by the analysis, the composite modulus, has been devised. A review of two dimensional long channel MOSFET modeling. UMESH KUMAR. Microelectron. Reliab. 20, 585 (1980). To obtain the necessary basic insight into the behaviour of MOSFET needed for device design and optimization, the basic equations must describe the two dimensional characteristics of the device. The increased power and availability of modern digital computers makes such an approach to derive most general and exact solutions feasible. A comprehensive review is made of the attempts at 2d MOSFET modeling. A two-dimensional placement algorithm for the layout of electronic circuits. HARIOM GUPTA and JAYDEV SHARIVlA. Microelectron. Reliab. 20, 323 (1980). A method is developed for the optimal placement of components or subsystems to specific locations on the backboard. The objective is to minimize the number of etches passing through unit space on the board (interconnection density) and the number of holes. This avoids the congested area on the board, makes a proper distribution of wiring and reduces the stray capacitances. X - Y coordinate wiring has been used.
6. MICROELECTRONICS--COMPONENTS, SYSTEMS AND EQUIPMENTS CMOS uncommitted logic arrays are part-digital, partanalog. DAN YODER, JR. Electronics, p. 163 (13 January 1981). Basic cells for logic and specialized analog quadrants serve many applications; software customizes metalization and contacts.
Fast 16-K static RAM tolerates faults. BRUCE LEBOSS. Electronics, p. 196 (13 January 1981). 55-ns RAM is made with double-polysilicon process, has three redundant rows to raise yield and polyimide to fight alphas. VLSI tester is highly modular. RICHARD W. COMERFORD. Electronics, p. 187 (13 January 1981). 40-MHz general-
purpose semiconductor test system, the first of a series, eases investment through modular hardware, software. CMOS comes of age. DAVID FULLAGAR. IEEE Spectrum, p. 24 (December 1980). Complementary metal-oxide semiconductors--at one time a "stepchild"--is leading the way in digital and analog circuits.
Charge build-up in MOS system under ionizing radiation. SWARAJ SRIVASTAVA,G. P. SRIVASTAVAand B. R. SINGH. Microelectron. Reliab. 20, 529 (1980). This paper reports the results on the charge formation in MOS system under ionizing radiation. The roles of different gate metals and oxide growth conditions are discussed.
7. SEMICONDUCTOR INTEGRATED CIRCUITS, DEVICES AND MATERIALS The diffusion of hot electrons across a semiconductor base. B. K. RIDLEY. Solid-St. Electron. 24, 147 (1981). A theoretical description of the diffusion of electrons injected at energies much greater than optical or inter-valley phonon energies into a semiconductor and their collection over a semiconductor-semiconductor barrier is given. Energy loss is assumed to be solely by collisions with high frequency phonons via the deformation-potential interaction, and specific solutions of the Boltzmann equation are obtained for a delta-function injection and parabolic bands. Application of the theory to silicon gives useful current-transfer ratio base widths of 150A and less, and the effect of quantummechanical reflection is found to be relatively unimportant. The results for the current-transfer ratios are dependent on
non-parabolicity in the conduction band of silicon, and a model for the latter is described. An effective attenuation length of 360A is predicted for silicon. The distribution function for hot electrons should reflect the variation of density-of-states in the conduction band.
Minority carrier injection and storage into a heavily doped emitter. Approximate solution for auger recombination. W. P. DUMKE. Solid-St. Electron. 24, 155 (1981). An analytic solution for the injected carrier distribution in a linearly graded, heavily doped region is given in terms of Hermite polynomials. The properties of this distribution are compared with those for the more usual diffusion length solution. An expression is given for the effect on high frequency