Patent ID: 8502309

Claim:
A semiconductor device comprising: a body layer of a first conductivity type; a source layer of a second conductivity type in a surface region of the body layer; an offset layer of the second conductivity type; a buried insulating film in a surface region of the offset layer; a drain layer of the second conductivity type adjacent to the offset layer; a gate insulating film at least on a surface region of a portion of the body layer between the source layer and the offset layer; and a gate electrode on the gate insulating film, wherein the offset layer is adjacent to the drain layer, and a portion of the offset layer is between the body layer and the buried insulating film, and an impurity concentration profile from a surface of the portion of the offset layer to a bottom of the offset layer has a first peak located at a position deeper than a bottom of the buried insulating film, and has a second peak located at a position shallower than the bottom of the buried insulating film.