Patent ID: 8686561

Claim:
A nitride-based semiconductor device comprising: a nitride-based semiconductor multilayer structure including a p-type semiconductor region, a surface of the p-type semiconductor region being an m-plane; and an electrode that is directly arranged on the p-type semiconductor region; wherein the p-type semiconductor region is made of an Al x In y Ga z N semiconductor (where x+y+z=1, xâ‰§0, yâ‰§0, z>0); the electrode comprises an Mg layer and a metal layer; the Mg layer is in direct contact with the p-type semiconductor region; the Mg layer consists of magnesium, gallium and nitride; the Mg layer has a thickness of not more than 45 nanometers; the Mg layer is interposed between the metal layer and the p-type semiconductor region; the metal layer is made of at least one metal that would make an alloy with Mg less easily than Au; and a concentration of gallium included in the Mg layer is greater than a concentration of nitride included in the Mg layer.