A semiconductor device and a manufacturing method thereof uses a semiconductor substrate of silicon carbide. On one principal surface side of the substrate, at its central section, a layer of silicon carbide or gallium nitride as a semiconductor layer having the thickness at least necessary for breakdown...http://www.google.de/patents/US7821014?utm_source=gb-gplus-sharePatent US7821014 - Semiconductor device and manufacturing method thereof with a recessed backside substrate for breakdown voltage blocking
