High-breakdown-voltage insulated gate semiconductor device

A semiconductor device comprising:

• a semiconductor substrate;
• a silicon carbide layer formed on the semiconductor substrate and having its top surface inclined at an angle of 10 degrees or less from a crystal plane in a miscut direction;
• a gate insulating film formed on the silicon carbide layer;
• a gate electrode formed on the gate insulating film;
• a source electrode formed on a part of the silicon carbide layer located to one side of the gate electrode;
• a drain electrode formed on a part of the silicon carbide layer located to the other side of the gate electrode;
• and
• source/drain regions formed apart from each other in regions of the silicon carbide layer located at least under the source and gate electrodes,
• wherein the opposed two of the edges of the source/drain regions extend along the direction perpendicular to the miscut direction in a plan view, and the semiconductor device contains a V-group element at the interface between the silicon carbide layer and the gate insulating film.