Patterning SOI with silicon mask to create box at different depths

Abstract

The present invention provides a method of fabricating a patterned silicon-on-insulator substrate which includes dual depth SOI regions or both SOI and non-SOI regions within the same substrate. The method of the present invention includes forming a silicon mask having at least one opening on a surface of Si-containing material, recessing the Si-containing material through the at least one opening using an etching process to provide a structure having at least one recess region and a non-recessed region, and forming a first buried insulating region in the non-recessed region and a second buried insulating region in the recessed region. In accordance with the present invention, the first buried insulating region in the non-recessed region is located above the second buried isolation region in the recessed region. A lift-off step can be employed to remove the first buried insulating region and the material that lies above to provide a substrate containing both SOI and non-SOI regions.

Dependencies are inferred from the claim text.