Formation of buried insulating layers by high dose oxygen implantation under controlled temperature conditions

A specially designed sample holder was used to form SOI structures by high dose oxygen implantation under controlled temperature conditions. This system uses a layer of molten tin to provide a good thermal contact between the silicon wafer and a resistively heated support. The layers formed under these conditions were characterized by RBS and XTEM. After annealing at 11500C for 2 h the only remaining defects in the top silicon layer are dislocations with a density of less than 107 cm-2 and SiO2 precipitates. Annealing at 11850C for 6 h does not change the density of dislocations but leads to the formation of a 200 nm thick silicon layer free of SiO2 precipitates, suitable for VLSI processing without growing an epitaxial layer. (author)