Patent ID: 9673313
Date: 2017-06-06
CPC Classifications: H01L

Claim:
1. A silicon carbide semiconductor device having a semiconductor device structure created inside a semiconductor substrate, the silicon carbide semiconductor device comprising: a gate pad configured to establish electric contact with an outside electrode, wherein the semiconductor device structure is formed in the semiconductor substrate at a lower portion beneath the gate pad, the semiconductor device structure includes: wherein the second impurity concentration is a greater concentration than the first impurity concentration and the third impurity concentration, a gate electrode formed over a gate insulation film on a surface of the base layer interposed between the source region and the well region, a plurality of the semiconductor device structure constituting a plurality of different cells, portions of the respective second-conductivity-type semiconductor layers of the different cells are connected to each other in a region under the respective well regions, wherein a portion of the source region under the gate pad is electrically connected to a portion of the source region of the semiconductor device structure other than the portion of the source region under the gate pad, the source region is surrounded by a second-conductivity-type semiconductor region, and a first area ratio of the portion of the source region under the gate pad compared with a whole portion under the gate pad is larger than a second area ratio of a portion of the source region under a source pad compared with a whole portion under the source pad.