FORMATION OF IMPROVED SOI SUBSTRATES USING BULK SEMICONDUCTOR WAFERS

摘要

The present invention relates to a semiconductor-on-insulator (SOI) substrate having one or more device regions. Each device region comprises at least a base semiconductor substrate layer and a semiconductor device layer with a buried insulator layer located therebetween, while the semiconductor device layer is supported by one or more vertical insulating pillars. The vertical insulating pillars each preferably has a ledge extending between the base semiconductor substrate layer and the semiconductor device layer. The SOI substrates of the present invention can be readily formed from a precursor substrate structure with a “floating” semiconductor device layer that is spaced apart from the base semiconductor substrate layer by an air gap and is supported by one or more vertical insulating pillars. The air gap is preferably formed by selective removal of a sacrificial layer located between the base semiconductor substrate layer and the semiconductor device layer.