Semiconductor device and method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, comprising:

• providing a substrate including a first semiconductor material having a bandgap wider than that of silicon, the substrate having a front surface and a rear surface;
• forming a deposition layer on the front surface of the substrate, the deposition layer having an impurity concentration lower than that of the substrate, the deposition layer having a first surface and a second surface opposite to each other, the second surface thereof facing the substrate;
• selectively forming a semiconductor region in the deposition layer at a side of the first surface thereof;
• forming a semiconductor layer on the first surface of the deposition layer, the semiconductor layer including a second semiconductor material having a bandgap wider than that of silicon;
• selectively forming a first region in the semiconductor layer so as to be on the deposition layer;
• selectively forming a second region in the semiconductor layer;
• forming a gate electrode on the second region and the semiconductor layer, via a gate insulating film;
• forming a source electrode in contact with the semiconductor layer and the second region;
• forming an interlayer insulating film covering the gate electrode;
• forming a drain electrode on the rear surface of the substrate;
• selectively forming a protective film on the source electrode;
• selectively forming a plating film on the source electrode, at a portion thereof on which the protective film is not formed;
• and
• forming a pin-shaped electrode connected to the plating film via solder, wherein
• the second region is so selectively formed that the semiconductor device is free of the second region directly beneath a triple junction portion where the plating film, the protective film and the source electrode are in contact with one another.