Patent ID: 8000364

Claim:
A nitride semiconductor light emitting device, comprising: an n-type nitride semiconductor layer provided over a substrate; a light emitting layer provided over the n-type nitride semiconductor layer, for emitting light of a predetermined wavelength; a p-type nitride semiconductor layer provided over the light emitting layer; an n-type ohmic electrode electrically connected to the n-type nitride semiconductor layer; and a p-type ohmic electrode electrically connected to the p-type nitride semiconductor layer, wherein the n-type ohmic electrode is a laminate composed of a first layer, a second layer, a third layer, and a fourth layer, from the near side of the n-type nitride semiconductor in order of mention, the first layer is a thin film containing Al (aluminum) as a main ingredient and has a thickness not greater than 10 nm and not less than 3 nm, the second layer is a thin film containing one or more metals selected from Mo (molybdenum) and Nb (niobium), so as to suppress the upward diffusion of Al, the third layer is a thin film containing one or more metals selected from Ti (titanium) and Pt (platinum), so as to suppress the downward diffusion of Al, and the fourth layer is made of Au (gold), and wherein the first layer is constructed to have a thickness selected to prevent Al diffusion-caused contamination at a surface of said n-type ohmic electrode at said fourth layer.