Silicon carbide semiconductor device and method of manufacturing the same

A silicon carbide semiconductor device comprising:

• a substrate made of silicon carbide and having one of a first conductivity type and a second conductivity type, the substrate having first and second opposing surfaces;
• a drift layer disposed on the first surface of the substrate, the drift layer made of silicon carbide and having the first conductivity type;
• a base region disposed on the drift layer and having the second conductivity type;
• a source region disposed above the base region and having the first conductivity type;
• a trench penetrating the source region and the base region to the drift layer;
• a gate insulating layer disposed on a surface of the trench;
• a gate electrode disposed on a surface of the gate insulating layer in the trench;
• a first electrode electrically coupled with the source region and the base region;
• a second electrode disposed on the second surface of the substrate;
• and
• a second conductivity-type layer disposed at a portion of the base region located under the source region, the second conductivity-type layer having the second conductivity type and having an impurity concentration higher than the base region, wherein
• an inversion channel is provided at a surface portion of the base region located on a side surface of the trench and electric current flows between the first electrode and the second electrode through the source region and the drift layer by controlling a voltage applied to the gate electrode.