Patent ID: 8350270

Claim:
A silicon carbide semiconductor device comprising: a silicon carbide substrate of a first conductivity type; a silicon carbide drift layer of the first conductivity type provided on a principal surface of the silicon carbide substrate; a pair of base regions provided in a surface layer portion of the silicon carbide drift layer while separated from each other and that exhibit a second conductivity type; a pair of source regions provided in interiors of surface layer portions of the pair of base regions and that exhibit a first conductivity type; a pair of silicon carbide semi-insulating regions provided between the silicon carbide substrate and the pair of base regions; a gate electrode provided on a surface of the silicon carbide drift layer through a gate insulating film; a source electrode adjoining the source regions and the base regions; and a drain electrode provided on a surface of the silicon carbide substrate opposite to the principal surface thereof, wherein spacing between the pair of silicon carbide semi-insulating regions at lower ends thereof is larger than spacing between the pair of silicon carbide semi-insulating regions at upper ends thereof.