Patent ID: 6946358

Claim:
A method of forming an isolation region and a buried oxide in a semiconductor substrate comprising: providing a structure having an oxide layer located on top of an upper surface of a semiconductor substrate; selectively implanting oxygen ions into the semiconductor substrate to form a first oxygen implant region in the upper surface region and a second oxygen implant region that is buried within the semiconductor substrate, wherein the step of selectively implanting oxygen ions comprises a step of first forming a patterned implant mask atop the oxide layer and implanting oxygen ions across the entire surface of the structure using an oxygen ion implantation process; annealing the oxygen implant regions to convert the first oxygen implant region into an isolation region having an upper surface that is substantially coplanar with the upper surface of the semiconductor substrate and to convert the second oxygen implant region into a buried oxide, said isolation region and said buried oxide are adjoining and are absent of an interface therebetween and said buried oxide has an upper surface that is below that of an upper surface of said isolation region so that a semiconductor region remains above the buried oxide, but not above the isolation region; and removing said oxide layer.