Patent ID: 7872274

Claim:
A semiconductor device, comprising: a substrate; and a Group III nitride compound semiconductor device formed on said substrate, said Group III nitride compound semiconductor device comprising: an n-type layer; and an n-electrode formed on said n-type layer for making an ohmic contact therewith, said n-electrode comprising: a first electrode material including at least one member selected from the group consisting of vanadium, zirconium and tungsten; a second electrode material including at least one member selected from the group consisting of palladium, platinum, silver and copper; and a third electrode material including at least one member selected from the group consisting of aluminum, silicon and germanium, wherein the first electrode material is formed directly on said n-type layer of said Group III nitride compound semiconductor device, wherein the second electrode material is disposed directly on the first electrode material, and wherein the third electrode material is disposed directly on the second electrode material, a film thickness ratio of said first, second, and third electrode materials being preset as based on a low desired contact resistance value for said n-electrode.