Patent attributes
A semiconductor light emitting device has: a semiconductor substrate; a semiconductor layer having an n-type cladding layer, an active layer, a p-type cladding layer and a p-type contact layer, wherein the p-type contact layer is made of an As-based material and located at the top of the semiconductor layer and doped with a p-type dopant at a concentration of 1×1019/cm3 or more; a current spreading layer formed on the semiconductor layer and made of a metal oxide material; and a diffusion prevention layer formed between the p-type contact layer and the p-type cladding layer. The diffusion prevention layer is made of a group III–V semiconductor that has phosphorus as a group V element and has a crystal lattice mismatch ratio of within ±0.3% to the semiconductor substrate.