Formation of buried insulating layers in silicon by the implantation of high doses of oxygen

Abstract Silicon wafers have been implanted with 200 keV oxygen to dosss of up to 2.4 × 10 18 O + /cm 2 at implantation temperatures of 325°C to 600°C. Rutherford backscattering and SIMS show the oxygen depth distribution is insensitive to the implantation temperature but is modified by subsequent high-temperature processing. Multiple laser irradiations produced a single crystal layer at the surface by LPE regrowth but better crystallinity is observed in samples which have been furnace annealed, when a layer of 1000 A thickness is formed which is denuded of oxygen. Preferred conditions to form a silicon on insulator structure (SOI) suitable for VLSI device technology are implantation temperature 400–500°C followed by furnace annealing at 1150°C for 2–4 h with an SiO 2 cap.