Semiconductor device and method for producing same

A vertical semiconductor device including a GaN-based stacked layer having an opening,

• the GaN-based stacked layer including n-type GaN-based drift layer/p-type GaN-based barrier layer/n-type GaN-based contact layer in that order, the opening extending from a top layer and reaching the n-type GaN-based drift layer, the semiconductor device comprising:
• a regrown layer located so as to cover a wall surface and a bottom portion of the opening, the regrown layer including an electron drift layer and an electron supply layer;
• a source electrode that is in contact with the n-type GaN-based contact layer and the regrown layer around the opening;
• and
• a gate electrode located on the regrown layer and having a terminal portion in the opening,
• wherein the gate electrode covers a portion of a wall surface of the regrown layer, the portion of the wall surface of the regrown layer being in contact with the p-type barrier layer in the opening, and the gate electrode is terminated at the terminal portion on the wall surface, the terminal portion of the gate electrode being away from a bottom portion of the regrown layer that covers the bottom portion of the opening.