Patent ID: 7535026

Claim:
A semiconductor light-emitting device, comprising: a semiconductor substrate; semiconductor layers formed on the semiconductor substrate, the semiconductor layers comprising an n-type cladding layer, an active layer, a p-type cladding layer, a p-type buffer layer, and a p-type contact layer; and a current spreading layer formed on the p-type contact layer, the current spreading layer comprising a metal-oxide material, wherein the active layer comprises (Al x1 Ga 1−x1 ) y1 In 1−y1 P (where 0≦X1≦1, 0.4≦Y1≦0.6, the n-type cladding layer and the p-type cladding layer respectively comprise (Al x2 Ga 1−x2 ) y2 In 1−y2 P(where 0.6≦X2≦1, 0.4≦Y2≦0.6), the p-type buffer layer comprises Al x3 Ga 1−x3 As (where 0.45≦X3≦1), the p-type cladding layer and the p-type buffer layer comprise Mg as a main dopant, the p-type contact layer comprises Zn as a main dopant, and a part or all of the p-type buffer layer comprises Mg-doped buffer layer and an undoped layer, the undoped buffer layer being provided at a side of the p-type contact layer.