| abstract |
This semiconductor device includes: a semiconductor layer having a structure in which a drain layer of a first conductivity type, a channel layer of a second conductivity type, and a source layer of the first conductivity type are layered in the stated order, the source layer being exposed on the outer surface of the semiconductor layer; a gate trench that passes through the source layer and the channel layer from the outer surface of the semiconductor layer, the deepest section of the gate trench reaching the drain layer; a gate insulating film formed on the inside surface of the gate trench, the gate insulating film being formed correspondingly with respect to the outer surface of the semiconductor layer; and a gate electrode embedded inside the gate trench interposed by the gate insulating layer. A portion of the gate insulating film that abuts the outer surface of the semiconductor layer is thicker than a portion that abuts the channel layer at a side surface of the gate trench. |