Patent ID: 8878194

Claim:
A semiconductor element comprising: a semiconductor substrate of a first conductivity type; a first silicon carbide semiconductor layer of the first conductivity type, which is located on the principal surface of the semiconductor substrate; a body region of a second conductivity type, which is located in the first silicon carbide semiconductor layer; a doped region of the first conductivity type, which is located in the body region; a second silicon carbide semiconductor layer of the first conductivity type, which is arranged on the first silicon carbide semiconductor layer so as to contact at least partially with the body region and the doped region; a gate insulating film on the second silicon carbide semiconductor layer; a gate electrode on the gate insulating film; a first ohmic electrode which is electrically connected to the doped region; and a second ohmic electrode which is arranged on the back surface of the semiconductor substrate, and wherein the body region includes a first body region and a second body region, the second body region being arranged at least under the first body region and contacting with the bottom of the body region, and wherein the first body region has a higher dopant concentration than the second body region, and wherein the doped region includes the dopant of the second conductivity type at a lower concentration than the first body region, and wherein a portion of the first body region that contacts with the second silicon carbide semiconductor layer is arranged shallower than another portion of the first body region that is located under the doped region, and wherein each of the first and second body regions has a bottom portion and a wall portion, and wherein in the first silicon carbide semiconductor layer, the doped region is located in a surface region of the first silicon carbide semiconductor layer, the bottom portion of the first body region is located under the doped region, and in a region of the first silicon carbide semiconductor layer under the gate electrode, the wall portion of the first body region is located beside the doped region and contacts with the surface of the first silicon carbide semiconductor layer, and the bottom portion of the second body region is located under the bottom portion of the first body region and in a region of the first silicon carbide semiconductor layer under the gate electrode, the wall portion of the second body region is located outside of the wall portion of the first body region.