Patent ID: 6737724
Filing Date: 2004-05-18
Classification: H01L

Abstract:
A semiconductor device, comprising:a semiconductor substrate of a first conductivity type; a high impurity concentration layer of the first conductivity type formed in at least a part of the semiconductor substrate; an epitaxial Si layer of the first conductivity type formed on a main surface of the semiconductor substrate and in contact with the high impurity concentration layer; a trench of a predetermined depth, selectively formed in the epitaxial Si layer and the semiconductor substrate; an insulating film for element isolation formed in the trench; a source region formed in a region where the insulating film for element isolation is not formed; and a drain region formed in a region where the insulating film for element isolation is not formed, the epitaxial Si layer being interposed between the source region and the drain region, wherein a depth of at least a part of undersurfaces of the source region and the drain region with respect to the main surface of the semiconductor substrate is deeper than a depth of an interface between an undersurface of the epitaxial Si layer and a surface of the high impurity concentration layer with respect to the main surface of the semiconductor substrate.