Single Crystal Silicon Epitaxy on Foreign Substrates

Abstract

Single crystal silicon has been grown epitaxially on a number of single crystal oxide substrates by chemical vapor deposition techniques. Such growth has been obtained in large area single crystal form on α-alumina, spinel, and beryllia. The distinct orientation relationships between the silicon deposits and a multiplicity of crystallographic planes of the various insulating substrates are indicated. Compatible with the earlier observed growths of single crystal tungsten on α-alumina, a model which assumes a fit between the silicon and the metal ion sites in the oxide substrate can account for all the epitaxial geometries. A concept of multiple fits in the metal-oxide system in terms of integral lattice parameter values as a guide in substrate selection is suggested. Representative electronic properties of the films and model fabricated devices, as well as a measure of their consequence in microelectronics, are given.