Patent ID: 8269272

Claim:
A semiconductor device comprising: a first semiconductor layer of a first conductivity type; a second semiconductor layer of the first conductivity type, provided on the first semiconductor layer, having a concentration of first conductivity type impurity lower than a concentration of first conductivity type impurity of the first semiconductor layer; a third semiconductor layer of a second conductivity type provided on the second semiconductor layer; a fourth semiconductor layer of the first conductivity type, provided on the third semiconductor layer, having a concentration of first conductivity type impurity higher than the concentration of the first conductivity type impurity of the second semiconductor layer; first trenches which penetrate the fourth semiconductor layer and the third semiconductor layer to reach the second semiconductor layer; a second trench which penetrates the fourth semiconductor layer and the third semiconductor layer, on a side closer to a termination than the first trenches, to reach the second semiconductor layer, the second trench dividing the fourth semiconductor layer and the third semiconductor layer into a element part including a region wherein the first trenches are formed and a termination part; an insulating film provided on internal walls of the first trenches and the second trench; a gate electrode provided in the first trenches via the insulating film; a first main electrode provided on the first semiconductor layer, on a surface opposite to a surface where the second semiconductor layer is provided; a second main electrode provided to contact the element part of the third semiconductor layer and the element part of the fourth semiconductor layer; a channel stopper layer provided in the second trench via the insulating film; and a channel stopper electrode provided on the termination part of the third semiconductor layer and the termination part of the fourth semiconductor layer and connecting the channel stopper layer and the termination part.