Patent ID: 7687908

Claim:
A thin film electrode for ohmic contact of a p-type GaN semiconductor, comprising: a first electrode layer stacked on a p-type GaN layer, the first electrode layer including one selected from the group consisting of an Ni-based alloy or solid solution (Ni—X), a Co-based alloy or solid solution (Co—X), and a nickel oxide doped with at least one selected from the group consisting of Al, Ga, and In, wherein the first electrode layer is a p-type thermo-electronic oxide; and a second electrode layer stacked on the first electrode layer, the second electrode layer including at least one selected from the group consisting of Au, Pd, Pt, Ru, Re, Sc, Mg, Zn, V, Hf, Ta, Rh, Ir, W, Ti, Ag, Cr, Mo, Nb, Ca, Na, Sb, Li, In, Sn, Al, Ni, Cu, and Co, wherein the Ni-based alloy or solid solution (Ni—X) uses Ni as a base element and the X element comprises one selected from the group consisting of Na, Ca, K, Cs, Sr, and Ba.