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Fundamentals of silicon epitaxy
World Abstracts on Microelectronics and Reliability 6. M I C R O E L E C T R O N I C S - - C O M P O N E N T S , IC packaging technology for electronic watches. YOSHIO hNUMA. Electrocomponent Sci. Technol. 8, 131 (1981). ICQuartz watches have been manufactured since the appearance of CMOS-LSI about seven years ago. Nowadays, the outside view of the quartz watch is the same as that of a mechanical watch through minimizing electronic parts such as battery, crystal oscillator, capacitor, and IC packaging volume. Recently, IC packaging technology for electronic wrist watches (both the analog quartz watch and digital quartz watch) has made a step forward. In Japan, some watch makers adopt a film carrier assembly technique for producing thin and low-priced watches. They are using 3 layers and 35 mm wide film which fits very well the substrate of the quartz watch, especially the digital quartz watch. The Citizen Watch Co., Ltd. started an investigation as to which method was suitable for IC package for watches in 1975 and adopted a flip chip technique as being the most
7. S E M I C O N D U C T O R
INTEGRATED
Fundamentals of silicon epitaxy. ROBERT W. ATHERTON. Semicond. Int., 117 (November 1981 ). Epitaxial growth is a specific example of chemical vapor deposition. Basic processes in CVD provide a basis for discussion of the Grove kinetic model for silicon epitaxy. Relevant mathematical equations and proposed chemical mechanisms are presented as an aid to this discussion. Applications of infrat~ed spectroscopy to the annealing of silicon. D. G. MEAD. Solid St. Technol., 71 (November 1981). The use of infrared spectroscopy to characterize annealed silicon and some phosphosilicate glass depositions are briefly reviewed and discussed. Examples in the 400-10,000 wave number range (1-250 microns) of the electromagnetic spectrum are given. In particular, spatial profiling, the effects of thermal annealing about the optical band edge, and the change in absorption features of phosphosilicate films deposited on silicon wafers have been investigated including some laser annealing studies. On an analytical solution for two-dimensional diffusion of silicon self-interstitials during oxidation of silicon. MASAHURU HAMASAKI.Solid-St. Electron. 25 (1), 1 (1982). An analytical solution for two-dimensional diffusion of silicon self-interstitials during the oxidation of silicon is presented. The lateral effect of oxidation enhanced diffusion of boron in silicon is explained by the solution, because the increment of diffusivity is proportional to the incremental concentration of interstitials. Agreement between theoretical and experimental increments of the diffusivity is excellent.
8. T H I C K -
AND THIN-FILM
SYSTEMS AND EQUIPMENTS suitable for analog quartz watches. The flip chip technique will allow the fabrication of a very small and thin package. Important characteristics of the technique permit design flexibility and high density packaging of the ICs. In this paper, a flip chip technique using a Printed Circuit Board as a substrate is described. Serially testing a board's states takes the trickiness out of debugging it. JAMESW. COFFRON. Electronics, 100 (January 27, 1982). Treating microprocessor operations as a sequence of electrical states makes it possible to check out even the earliest stages of system design. Teachable work station brings order to VLSI chip design. STEPHEN C. JOHNSON,GEKD H. SCHUTT and VICKIPERKINS. Electronics, 108 (January 27, 1982). Turnkey system assimilates use-specific commands; ranks tasks with its data-base manager; displays two views of circuit at one time.
CIRCUITS,
Pattern shift and pattern distortion during CVD epitaxy on (111) and (100) silicon. S. P. WEEKS.Solid St. Technol., 111 (November 1981 ). A survey of experimental data on pattern shift and pattern distortion during CVD epitaxial growth on (111 ) and (100) silicon substrates shows the general trends of shift and distortion as a function of variable reactor parameters. A simple model of edge displacement based on anisotropic crystal growth explains the general behaviour observed.
1193
DEVICES
AND MATERIALS
The influence of boron induced and oxidation induced defects on bipolar transistor slice yield. R. R. SUTHERLAND.Solid-St. Electron. 25 (1), 15 (1982). Silicon lattice defects induced by high concentration boron diffusion, or by oxidation, are a major cause of high leakage currents in bipolar transistors. The incidence of such defects in narrow base, high frequency, transistors is investigated using Sirtl etch and the transmission electron microscope, and related to the transistor leakage currents. Boron induced defects are found to cause high emitter-base leakage, but it is shown that their density may be reduced by a nitric acid boron glass strip prior to base drive. A particular type of oxidation induced defect is found to cause high collector-emitter leakage, and appearance of this defect is correlated with silicon material batch. As an example, yields of slices of the British Telecom 40 Type submarine cable transistor meeting a specification including low leakage currents, are shown to be related closely to the silicon material/boron glass strip combination used. Process conditions affecting hot electron trapping in DC magnetron sputtered MOS devices. N. A. BOJARCZUK. Solid St. Technol., 76 (December 1981). Process parameters affecting hot electron trapping in MOS capacitors produced by magnetron sputtered aluminium were studied. The electron traps considered are process unduced and affected by changes in sputtering parameters. Devices were fabricated under each of the following varying conditions: target presputter time, deposition power, source to substrate distance, process pressure, deposition thickness, anode bias voltage and annealing temperature. Mobile ion concentration, surface state and flatband voltage measurements revealed values less than 4 x 101° charges/cm2, 3.7x 101° states/cm2eV and - 1.2 V after a 400°C anneal in 10 % H2/90 % N 2 forming gas mixture. Hot electron injection measurements of the devices after the same anneal resulted in minimum effective electron trapping (4.25x 101° electrons/cmz trapped for 9x 10 t'~ electrons/cm2 injected) when the process conditions were optimized. The optimized parameters reduced the trapping density and improved device performance.
COMPONENTS,
HYBRID
CIRCUITS
AND MATERIALS Thick film capacitor materials of the powder-glass binary systems and their dielectric properties. AKIRA IKEGAM1,HIDEO AR1MA and KATSUOABE. Electrocomponent Sci. Technol. 9, 147 (1981). Descriptions are given of the fundamental dielectric properties of the thick film binary system, composed MR
22:6
- J
of dielectric powder and glass, in relation to the effect of bulk properties of the constituent electrode composition in preventing a decrease in breakdown voltage with time and the effect of glass passivation on the reliability of thick film capacitors.
7. S E M I C O N D U C T O R
INTEGRATED
Fundamentals of silicon epitaxy. ROBERT W. ATHERTON. Semicond. Int., 117 (November 1981 ). Epitaxial growth is a specific example of chemical vapor deposition. Basic processes in CVD provide a basis for discussion of the Grove kinetic model for silicon epitaxy. Relevant mathematical equations and proposed chemical mechanisms are presented as an aid to this discussion. Applications of infrat~ed spectroscopy to the annealing of silicon. D. G. MEAD. Solid St. Technol., 71 (November 1981). The use of infrared spectroscopy to characterize annealed silicon and some phosphosilicate glass depositions are briefly reviewed and discussed. Examples in the 400-10,000 wave number range (1-250 microns) of the electromagnetic spectrum are given. In particular, spatial profiling, the effects of thermal annealing about the optical band edge, and the change in absorption features of phosphosilicate films deposited on silicon wafers have been investigated including some laser annealing studies. On an analytical solution for two-dimensional diffusion of silicon self-interstitials during oxidation of silicon. MASAHURU HAMASAKI.Solid-St. Electron. 25 (1), 1 (1982). An analytical solution for two-dimensional diffusion of silicon self-interstitials during the oxidation of silicon is presented. The lateral effect of oxidation enhanced diffusion of boron in silicon is explained by the solution, because the increment of diffusivity is proportional to the incremental concentration of interstitials. Agreement between theoretical and experimental increments of the diffusivity is excellent.
8. T H I C K -
AND THIN-FILM
SYSTEMS AND EQUIPMENTS suitable for analog quartz watches. The flip chip technique will allow the fabrication of a very small and thin package. Important characteristics of the technique permit design flexibility and high density packaging of the ICs. In this paper, a flip chip technique using a Printed Circuit Board as a substrate is described. Serially testing a board's states takes the trickiness out of debugging it. JAMESW. COFFRON. Electronics, 100 (January 27, 1982). Treating microprocessor operations as a sequence of electrical states makes it possible to check out even the earliest stages of system design. Teachable work station brings order to VLSI chip design. STEPHEN C. JOHNSON,GEKD H. SCHUTT and VICKIPERKINS. Electronics, 108 (January 27, 1982). Turnkey system assimilates use-specific commands; ranks tasks with its data-base manager; displays two views of circuit at one time.
CIRCUITS,
Pattern shift and pattern distortion during CVD epitaxy on (111) and (100) silicon. S. P. WEEKS.Solid St. Technol., 111 (November 1981 ). A survey of experimental data on pattern shift and pattern distortion during CVD epitaxial growth on (111 ) and (100) silicon substrates shows the general trends of shift and distortion as a function of variable reactor parameters. A simple model of edge displacement based on anisotropic crystal growth explains the general behaviour observed.
1193
DEVICES
AND MATERIALS
The influence of boron induced and oxidation induced defects on bipolar transistor slice yield. R. R. SUTHERLAND.Solid-St. Electron. 25 (1), 15 (1982). Silicon lattice defects induced by high concentration boron diffusion, or by oxidation, are a major cause of high leakage currents in bipolar transistors. The incidence of such defects in narrow base, high frequency, transistors is investigated using Sirtl etch and the transmission electron microscope, and related to the transistor leakage currents. Boron induced defects are found to cause high emitter-base leakage, but it is shown that their density may be reduced by a nitric acid boron glass strip prior to base drive. A particular type of oxidation induced defect is found to cause high collector-emitter leakage, and appearance of this defect is correlated with silicon material batch. As an example, yields of slices of the British Telecom 40 Type submarine cable transistor meeting a specification including low leakage currents, are shown to be related closely to the silicon material/boron glass strip combination used. Process conditions affecting hot electron trapping in DC magnetron sputtered MOS devices. N. A. BOJARCZUK. Solid St. Technol., 76 (December 1981). Process parameters affecting hot electron trapping in MOS capacitors produced by magnetron sputtered aluminium were studied. The electron traps considered are process unduced and affected by changes in sputtering parameters. Devices were fabricated under each of the following varying conditions: target presputter time, deposition power, source to substrate distance, process pressure, deposition thickness, anode bias voltage and annealing temperature. Mobile ion concentration, surface state and flatband voltage measurements revealed values less than 4 x 101° charges/cm2, 3.7x 101° states/cm2eV and - 1.2 V after a 400°C anneal in 10 % H2/90 % N 2 forming gas mixture. Hot electron injection measurements of the devices after the same anneal resulted in minimum effective electron trapping (4.25x 101° electrons/cmz trapped for 9x 10 t'~ electrons/cm2 injected) when the process conditions were optimized. The optimized parameters reduced the trapping density and improved device performance.
COMPONENTS,
HYBRID
CIRCUITS
AND MATERIALS Thick film capacitor materials of the powder-glass binary systems and their dielectric properties. AKIRA IKEGAM1,HIDEO AR1MA and KATSUOABE. Electrocomponent Sci. Technol. 9, 147 (1981). Descriptions are given of the fundamental dielectric properties of the thick film binary system, composed MR
22:6
- J
of dielectric powder and glass, in relation to the effect of bulk properties of the constituent electrode composition in preventing a decrease in breakdown voltage with time and the effect of glass passivation on the reliability of thick film capacitors.