Semiconductor device, method for manufacturing the semiconductor device, and power conversion device

A semiconductor device comprising:

• a semiconductor substrate having a drift layer of a first conductivity type;
• an anode layer of a second conductivity type provided on the drift layer and constituting a PN junction diode together with the drift layer;
• a well layer of the first conductivity type provided on the anode layer;
• a low-concentration source layer of the second conductivity type provided on the well layer;
• a high-concentration source layer of the second conductivity type provided only in a portion of the low-concentration source layer;
• a gate electrode which is adjacent to the anode layer, the well layer, and the low-concentration source layer with a gate oxide film interposed therebetween and constitutes a MOSFET together with the anode layer, the well layer, and the low-concentration source layer;
• an insulating film covering the anode layer, the low-concentration source layer, the high-concentration source layer, and the gate electrode;
• and
• a contact hole penetrating the insulating film, the high-concentration source layer, the low-concentration source layer, and the well layer.