Silicon carbide semiconductor device and method of manufacturing silicon carbide semiconductor device

A silicon carbide semiconductor device having an active region through which a current passes, and a termination structure portion disposed outside of the active region and in which a voltage withstanding structure surrounding a periphery of the active region is formed, the silicon carbide semiconductor device comprising:

• a semiconductor substrate of a second conductivity type, having a first main surface and a second main surface opposite to each other;
• a first semiconductor layer of the second conductivity type, provided on the first main surface of the semiconductor substrate;
• a second semiconductor layer of a first conductivity type, provided on a surface of the first semiconductor layer, at a side thereof opposite to a side facing the semiconductor substrate;
• a plurality of first semiconductor regions of the second conductivity type, provided in a surface layer of the second semiconductor layer, at a side thereof opposite to a side facing the semiconductor substrate;
• a plurality of second semiconductor regions of the first conductivity type, provided in surface layers of the first semiconductor regions, at sides thereof opposite to sides facing the semiconductor substrate, the second semiconductor regions having an impurity concentration higher than that of the second semiconductor layer;
• a gate insulating film provided on surfaces of regions of the first semiconductor regions, between the second semiconductor layer and the second semiconductor regions;
• a gate electrode provided on the gate insulating film;
• a first electrode in contact with the first semiconductor regions and the second semiconductor regions;
• and
• a second electrode provided on the second main surface of the semiconductor substrate, wherein
• during bipolar operation of the silicon carbide semiconductor device, a smaller density as between an electron density and a hole density of the second semiconductor layer in the termination structure portion at an end thereof is at most 1×1015/cm3, the end of the termination structure portion being located at a side opposite to a side where the active region is provided.