Patent ID: 6750526
Filing Date: 2004-06-15
Classification: H01L

Abstract:
A semiconductor device, comprising:a semiconductor substrate of a first conductive type having a main surface; a layer of a second conductive type formed on said main surface of said semiconductor substrate; a trench portion, having sidewalls and a bottom, created so as to penetrate said layer of the second conductive type and so as to reach to a region in said semiconductor substrate for separating said layer of the second conductive type into one element formation region and another element formation region; an insulating film formed continuously on the sidewalls and bottom of said trench; and a buried semiconductor region formed on said insulating film so as to fill in said trench portion; wherein said insulating film is formed from the bottom over to the edges of the opening of said trench portion having an approximately uniform film thickness so as not to give any stress to said layer of the second conductive type, and an upper part of said trench portion is sandwiched by said layer of the second conductivity type.