Patent ID: 8901573

Claim:
A silicon carbide semiconductor device comprising: a semiconductor substrate including a first conductivity type substrate, a first conductivity type drift layer on the first conductivity type substrate, a second conductivity type layer on the drift layer, and a first conductivity type layer on the second conductivity type layer; a transistor formed in a transistor cell region of the semiconductor substrate; and an outer voltage-breakdown-resistant structure formed in an outer voltage-breakdown-resistant structure region which surrounds an outer periphery of the transistor cell region, wherein the outer voltage-breakdown-resistant structure formed in an outer voltage-breakdown-resistant structure region includes a first recess which surrounds the outer periphery of the transistor cell region, a first trench located at a side surface of the first recess on an inner periphery of the first recess, and an electric field relief structure having a second conductivity type buried layer, the first recess is deeper than the first conductivity type layer and the second conductivity type layer and reaches the drift layer, the first trench surrounds the outer periphery of the transistor cell region, and the second conductivity type buried layer is buried in the first trench and provides the side surface of the first recess.