Patent ID: 8748899

Claim:
A nitride-based semiconductor device comprising: a nitride-based semiconductor multilayer structure including a p-type semiconductor region; and an electrode that is arranged on the p-type semiconductor region, wherein the p-type semiconductor region is a GaN-based semiconductor made of an Al x In y Ga z N (where x+y+z=1, x≧0, y≧0 and z>0) semiconductor, the p-type semiconductor region is a semiconductor layer that defines a tilt angle of at least one degree with respect to an m plane, an angle of 1 to 5 degrees being formed between a normal to a principal surface of the p-type semiconductor region and a normal to the m plane, the electrode is arranged on the principal surface of the p-type semiconductor region, the electrode includes an Mg layer, which is in contact with the principal surface of the p-type semiconductor region, and a metal layer formed on the Mg layer, the metal layer is formed from at least one metallic element that is selected from the group consisting of Pt, Mo and Pd, and the concentration of Ga in the Mg layer is higher than that of nitrogen in the Mg layer.