Semiconductor device and semiconductor device manufacturing method

A semiconductor device manufacturing method comprising:

• forming a first-conductive-type first silicon carbide layer on a first principal surface of a silicon carbide substrate;
• forming a first ion implantation mask on an upper surface of the first silicon carbide layer;
• forming a first silicon carbide region by ion-implanting a second-conductive-type impurity in the first silicon carbide layer using the first ion implantation mask;
• forming a second ion implantation mask on an upper surface of the first silicon carbide layer;
• forming a second silicon carbide region by ion-implanting a first-conductive-type impurity in the first silicon carbide layer using the second ion implantation mask;
• forming a third silicon carbide region by ion-implanting the second-conductive-type impurity in the first silicon carbide layer using the second ion implantation mask;
• forming continuously a gate insulating film on surfaces of the second silicon carbide region, the first silicon carbide region, and the first silicon carbide layer;
• forming a gate electrode on the gate insulating film;
• forming an interlayer insulating film on the gate electrode;
• forming a trench piercing through the second silicon carbide region to reach the third silicon carbide region;
• forming a first electrode on the second silicon carbide region on a side surface of the trench while the first electrode contains a metallic element selected from a group consisting of Ni, Ti, Ta, Mo, and W;
• forming a second electrode on the third silicon carbide region in a bottom portion of the trench while the second electrode contains Al;
• forming a first main electrode on the second electrode;
• and
• forming a second main electrode on a second principal surface of the silicon carbide substrate.