Patent ID: 7646036

Claim:
A positive electrode formed on a p-type Group III nitride-based compound semiconductor layer, the electrode comprising: a light-transmitting electrode layer comprising a metal oxide; a reflecting electrode layer comprising a silver-base alloy formed from a silver alloy to which oxygen has been added as an additive in an amount of 0.1 mol % to 10 mol %; a conductive diffusion-preventing layer for preventing migration of silver to an upper layer with respect thereto, the conductive diffusion-preventing layer comprising one of: at least one of a high-melting-point metal and a metal nitride; and a multi-layer structure including at least one layer comprising at least one of a high-melting-point metal and a metal nitride; and a thick-film layer comprising gold or a gold-base alloy, wherein these layers are sequentially stacked, in the order given, on the p-type semiconductor layer.