Patent ID: 7829914

Claim:
A nitride semiconductor light-emitting device comprising: a buffer layer on a sapphire substrate, wherein the buffer layer includes a plurality of layers having different lattice constants; a first n-type nitride semiconductor layer on the buffer layer; an active layer on the first n-type nitride semiconductor layer; and a p-type nitride semiconductor layer on the active layer, wherein the buffer layer comprises: a first buffer layer on the sapphire substrate, wherein the first buffer layer has a larger lattice constant than the sapphire substrate; a second buffer layer on the first buffer layer, wherein the second buffer layer has a smaller lattice constant than the first buffer layer; and a third buffer layer on the second buffer layer, wherein the third buffer layer has a smaller lattice constant than the second buffer layer, the third buffer layer having a smaller lattice constant than the sapphire substrate, wherein the buffer layer includes a multi-stacked structure configured with at least one silicon layer, at least one InN layer, and at least one AlN layer.