Oxygen distributions in synthesized SiO2 layers formed by high dose O+ implantation into silicon

Abstract Oxygen depth distributions have been determined, in silicon on insulator (SOI) structures formed by implantation of 200 keV oxygen ions into (100) silicon wafers. The implanted layers have been studied by RBS, SIMS and cross-sectional TEM and a computer model has been developed which enables the evolution of the oxygen distribution to be followed. Processing conditions, to form SOI substrates for fabrication of VLSI devices in the top silicon layer, are implantation energy 200 keV, dose 1.8 × 10 18 O cm −2 and implantation temperature 500°C. An anneal at 1150°C for 2 h is required to form a thin single crystal layer, which is depleted of oxygen. The dielectric properties of the stoichiometric SiO 2 are improved by this thermal processing.