Patent ID: 8174066

Claim:
A semiconductor device comprising: a semiconductor layer; a first conductivity type region of a first conductivity type disposed in a base layer portion of the semiconductor layer; a body region of a second conductivity type disposed in the semiconductor layer so as to be in contact with the first conductivity type region; a trench extending from a surface of the semiconductor layer to pass through the body region so that a deepest portion of the trench reaches the first conductivity type region; a gate insulating film disposed on a bottom surface and a side surface of the trench; a gate electrode having a gate width, and disposed in the trench on the gate insulating film; a source region of the first conductivity type disposed on a side of the trench in a surface layer portion of the semiconductor layer so as to be in contact with the body region; a high-concentration region of the second conductivity type disposed in the body region at a position opposed to the trench and having a higher second conductivity type impurity concentration than that of the body region; and a channel implant region, containing a first conductivity type impurity, disposed in the body region between the trench and the high-concentration region.