Patent ID: 8803226

Claim:
A semiconductor device including a trench gate type field effect transistor and a diode which are formed in a semiconductor substrate, the semiconductor device comprising: a first trench and a second trench which are formed in the semiconductor substrate; a gate electrode of the trench gate type field effect transistor, the gate electrode being formed in the first trench through a gate insulating film; a conductive material formed in the second trench through a first insulating film; and a first semiconductor region of a first conductivity type and a second semiconductor region of a second conductivity type opposite to the first conductivity type which are used for the diode and formed in the semiconductor substrate, wherein the second trench is formed so as to surround the second semiconductor region in a planar view, wherein a part of the first semiconductor region is formed directly below the second semiconductor region, wherein a PN junction is formed between the second semiconductor region and the part of the first semiconductor region located directly below the second semiconductor region, and thereby the diode is formed, and wherein the conductive material is electrically coupled to one of the first semiconductor region and the second semiconductor region.