Patent ID: 7718231
Filing Date: 2010-05-18
Classification: H01L

Abstract:
1. A method of fabricating a substrate comprising: forming a porous Si-containing region via electrolytic anodization of a Si-containing region having n-type or p-type dopant in an upper portion of a Si-containing substrate; forming a single crystal Si-containing layer directly on top of said porous Si-containing region by epitaxial deposition; forming an oxygen implant region by implanting oxygen ions into the porous Si-containing region, wherein a peak oxygen content is provided by the implanting of the oxygen ions, and is located within said porous Si-containing region or at an interface between said single crystal Si-containing layer and said porous Si-containing region; and annealing using a thermal oxidation process at a temperature at which said implanted oxygen ions precipitate as oxides, wherein said precipitated oxides combine to form a uniform buried oxide layer extending across an entirety of a semiconductor-on-insulator (SOI) substrate, wherein after the annealing portions of the porous Si-containing region located beneath said uniform buried oxide layer now contain voids created by a collapse of previously existing pores in the porous Si-containing region, wherein a variation of thickness of said uniform buried oxide layer across said entirety of said Si-containing substrate is less than 30% of a total thickness of said uniform buried oxide layer, and wherein a Si-containing over-layer is formed from a remaining portion of said single crystal Si-containing layer.