Method for fabrication of silicon on insulator substrates

Abstract

A method for forming a silicon on insulator region on a single crystal silicon substrate, comprising the steps of: forming a first dielectric region in a silicon substrate by etching, deposition, and chemical-mechanical polishing; forming a single crystal layer on the substrate by polysilicon deposition and re-growth or epitaxial grownth; removing portions of the single crystal layer to produce silicon islands that are fully on the first dielectric region; and filling in the spaces between the silicon islands with a second dielectric, by deposition and chemical-mechanical-polish, that overlaps peripheral portions of the first dielectric. Additional steps sub-divide the fully isolated silicon on insulator regions by etching trenches in the islands and backfilling with a third dielectric, by deposition and chemical-mechanical-polish.