The Current Status of Silicon-On-Sapphire and other Heteroepitaxial Silicon-On-Insulator Technologies

Abstract

ABSTRACTThe present understanding of the properties of thin (≤0.6 μm) heteroepitaxial Si films grown on single-crystal bulk and thin film insulators is reviewed. Three areas are covered: (a) as-deposited Si films on bulk insulators, with particular emphasis on sapphire and cubic zirconia (b) post-growth processing methods to reduce the defect concentration and compressive strain in such Si films and (c) the growth and properties of monocrystalline insulating films on bulk Si and of Si on such films. The desired characteristics of the insulating material are given, and it is shown that the mismatch in thermal expansion coefficients between the insulator and Si dominates the properties of heteroepitaxial Si films. Present and future areas of application for Si-on-insulator technologies are briefly described, and directions for further studies are proposed.