SINGLE CRYSTAL SILICON FILMS ON INSULATING SUBSTRATES.
AUTONETICS ANAHEIM CA
The basic mechanism by which silicon is deposited on alumina from silane and hydrogen is discussed. The relationships which exist between crystal quality, deposition temperature and initial growth rate are presented in the form of a graph. The effect of heat treatments intended to anneal defects is shown to be small. Growth on silicon substrates and on alumina substrates suggests that the residual imperfections are due partly to differences in expansion and partly to lattice mismatch and neither seems to be susceptible to post growth removal. Improvements in silicon film material have been reflected in a considerable reduction in diffusion piping effects when high surface concentration phosphorus diffusions are used. Good results previously obtained on silicon-on-sapphire SCL MOS transistors have been duplicated. Silicon-on-sapphire has been employed to fabricate working p-channel MOS shift registers. The circuits are quasi-static, dual 2-bit units operating on a 4-phase clocking scheme. The circuits, while modest in size, demonstrate 1 functioning of a circuit design based upon use of the silicon-on-sapphire device isolation capability to a functional circuit requirement. Four-bit delays were observed by external hook-up of the 2-bit sections over a cycle range from 12 kHz to 2.5 MHz. Author