Patent ID: 7821014

Claim:
A semiconductor device comprising: a semiconductor substrate composed of silicon carbide having a first principal surface side and a second principal surface side opposite the first principal surface side; a semiconductor layer composed of one of silicon carbide or gallium nitride having a first predetermined thickness; an active region on the semiconductor layer, wherein the semiconductor layer is on the first principal surface side of the substrate at a central section of the first principal surface side, wherein the semiconductor layer has side walls each with a mesa groove that forms a planar breakdown voltage blocking structure having a mesa profile, with the semiconductor layer being wider at the first principal surface side of the semiconductor substrate than at a side of the active region, wherein in the second principal surface side of the substrate, the substrate has a recess aligned with the active region at a position facing the central section, and the substrate has a supporting section that surrounds a bottom of the recess and defines side faces of the recess, wherein the recess partly extends into the semiconductor substrate without extending through the semiconductor substrate so that a second predetermined thickness exists between the bottom of the recess and the first principal surface side, wherein the bottom of the recess is closest to the first principal surface side and is recessed from and farthest from an opening of the recess at the second principal surface side in a direction perpendicular to the second principal surface side, and wherein the side faces each have a mesa profile, with the opening of the recess at the second principal surface side being wider than at the bottom of the recess.