Patent ID: 6503811
Filing Date: 2003-01-07
Classification: H01L

Abstract:
A method for fabricating a substrate having a semiconductor layer as an SOI layer, comprising:a step for forming an insulating layer on a semiconductor substrate layer having recesses on a surface, said recesses having a depth larger than the intended final thickness of an SOI layer to be obtained, said insulating layer filling said recesses on said surface, and polishing said insulating layer on a surface opposite said recesses to form a polished surface; bonding a base substrate on said polished surface and thinning said semiconductor substrate layer while bonded, leaving said semiconductor layer only in said recesses; an etching step for etching the insulating layer using the residual semiconductor layer as an etching mask thereby to reduce the depth of the recesses; and a thinning step for polishing the remaining semiconductor layer while ensuring a selectivity over the insulating layer thereby to reduce the thickness of the semiconductor layer, thus to obtain an SOI substrate.