Capping Techniques for Zone-Melting-Recrystallized Si-ON-Insulator Films

摘要

To prepare silicon-on-insulator (SOI) films by graphite-strip-heater zone-melting recrystallization (ZMR), a capping technique must be used to insure wetting by the molten Si zone. Two new capping techniques that result in reproducible wetting without degrading the crystallographic texture of the recrystallized film are demonstrated: annealing SiO2 capped Si films in NH3 and depositing two SiNx layers with carefully controlled compositions on the SiO2 capping layer. Wetting is promoted by the incorporation of trace amounts of nitrogen at the Si-SiO2 interface. Both N implantation experiments and Auger spectroscopy studies establish that the presence of less than a monolayer of nitrogen at this interface is sufficient to insure wetting.