US Patent 7847296 Silicon carbide semiconductor device

On a major surface of an n-type silicon carbide inclined substrate (2) is formed an n-type voltage-blocking layer (3) made of silicon carbide by means of epitaxial growth. On the n-type voltage-blocking layer (3) is formed a p-type silicon carbide region (4) rectangular when viewed from above. On the surface of the p-type silicon carbide region (4) is formed a p-type contact electrode (5). In the p-type silicon carbide region (4), the periphery of the p-type silicon carbide region (4) that is parallel with a (11-20) plane (14a) of the silicon carbide crystal, which is liable to cause avalanche breakdown, is located on the short side. In this manner, the dielectric strength of a silicon carbide semiconductor device can be improved.