Semiconductor device and method of manufacturing semiconductor device

A semiconductor device comprising:

• an n-type gallium oxide semiconductor layer that has a center region and a peripheral region having a lower donor density than the center region;
• an electrode layer that is laminated on the n-type gallium oxide semiconductor layer, and forms Schottky junction with the n-type gallium oxide semiconductor layer in the center region as viewed from a lamination direction;
• and
• a first p-type nickel oxide semiconductor layer that is laminated on the n-type gallium oxide semiconductor layer such that the first p-type nickel oxide semiconductor layer is partially positioned between the n-type gallium oxide semiconductor layer and the electrode layer, and has an outer peripheral end portion on a peripheral region side in the peripheral region as viewed from the lamination direction,
• wherein the first p-type nickel oxide semiconductor layer is positioned to straddle the center region and the peripheral region as viewed from the lamination direction.