Patent ID: 7982224

Claim:
A semiconductor device comprising: a semiconductor substrate of silicon carbide of a first conductivity type, which has a principal surface and a back surface that is opposite to the principal surface; a silicon carbide epitaxial layer of the first conductivity type, which has been grown on the principal surface of the semiconductor substrate and which has a lower dopant concentration than the semiconductor substrate; well regions of a second conductivity type, which form parts of the silicon carbide epitaxial layer; source regions of the first conductivity type, which form respective parts of the well regions; and a channel epitaxial layer of silicon carbide of the first conductivity type, which has been grown on the silicon carbide epitaxial layer, wherein the channel epitaxial layer includes: a first portion, which is located over the source regions; a second portion, which is located over another part of the silicon carbide epitaxial layer where the well regions are not defined; and a channel region, which is located over the well regions and which is interposed between the first and second portions, and wherein the dopant concentration of the first and second portions is lower than that of the source regions but higher than that of the channel region.