SEMICONDUCTOR DEVICE

A semiconductor device includes a semiconductor layer of a first conductivity type that has a main surface and that includes a device region, a base region of a second conductivity type that is formed in a surface layer portion of the main surface at the device region, a source region of the first conductivity type that is formed in a surface layer portion of the base region at an interval inward from a peripheral portion of the base region and that defines a channel region with the semiconductor layer, a base contact region of the second conductivity type that is formed in a region different from the source region at the surface layer portion of the base region and that has an impurity concentration exceeding an impurity concentration of the base region, a well region of the first conductivity type that is formed in the surface layer portion of the main surface at an interval from the base region at the device region and that defines a drift region with the base region, a drain region of the first conductivity type that is formed in a surface layer portion of the well region, an impurity region of the second conductivity type that is formed in the surface layer portion of the well region and that is electrically connected to the drain region, and a gate structure that has a gate insulating film covering the channel region on the main surface and a gate electrode facing the channel region on the gate insulating film and electrically connected to the source region and the base contact region.