Patent ID: 7679132

Claim:
A silicon carbide semiconductor device comprising: a semiconductor substrate comprising silicon carbide, which contains a first conductivity type impurity diffused therein in a high concentration; a semiconductor layer formed over the semiconductor substrate and containing the first conductivity type impurity diffused therein in a low concentration; a plurality of well regions formed on a front surface side of a cell forming area set to the semiconductor layer and in which a second conductivity type impurity corresponding to a type opposite to the first conductivity type impurity is diffused; source layers formed on the front surface side lying within the well regions and each containing the first conductivity type impurity diffused therein in a high concentration; an outer peripheral insulating film thick in thickness, which is formed over the semiconductor layer in an outer peripheral area surrounding the cell forming area; a gate oxide film formed over the front surface of the semiconductor layer in the cell forming area; and a gate electrode layer formed so as to extend from above the gate oxide film to above the outer peripheral insulating film, wherein each of steplike portions adjacent to the outer peripheral insulating film and thicker than the gate oxide film in thickness is provided at an edge portion of the gate oxide film.