Patent ID: 7442992
Filing Date: 2008-10-28
Classification: H01L

Abstract:
1. A bonded SOI substrate, comprising: an SOI layer having a low density dopend impurity layer and a high density doped impurity layer which is adjacent to the low density doped impurity layer and in which dopants are present at a high density that is higher than that of the low density doped impurity layer; a wafer for a support substrate which supports said SOI layer; and a buried insulating film which bonds said SOI layer with said wafer for a support substrate, wherein said high density doped impurity layer is positioned on said buried insulating layer, the low density doped impurity layer is positioned on the high density doped impurity layer, and gettering sites including lattice defects are formed by heat-treating the high density doped impurity layer and are positioned at the boundary between the high density doped impurity layer and the buried insulated film.