Patent ID: 6809375
Filing Date: 2004-10-26
Classification: H01L

Abstract:
A semiconductor device, comprising:a semiconductor substrate, in which a drain layer of a first conductivity type and a conductive region of a second conductivity type opposite to the first conductivity type are formed with the conductive region over the drain layer; a trench formed in the conductive region, wherein said trench reaches the drain layer; a source region of the first conductivity type, wherein said source region is positioned inside the conductive region, with at least part of the source region being exposed to inner surfaces of the trench; a gate insulating film that is formed on the inner surfaces of the trench; a gate electrode that is formed on inner surfaces of the gate insulating film; and a source electrode that is insulated from the gate electrode and is connected to the source region; wherein the inner surface of the gate insulating film at a bottom of the trench is deeper than the source region but shallower than an interface between the drain layer and the conductive region.