Patent ID: 6992331

Claim:
A GaN based compound semiconductor light-emitting device (LED), comprising: a substrate; a multi-layer epitaxial structure comprising: a buffer layer being an LT-GaN/HT-GaN layer formed over an upper surface of said substrate, wherein said LT-GaN is a low temperature layer first formed over said substrate, and said HT-GaN layer is a high temperature layer then formed over said LT-GaN layer; a first semiconductor layer being an n-GaN based compound semiconductor layer formed over said buffer layer; a light generating layer being a GaN based compound semiconductor active layer comprising a GaN multi-layer quantum well (MQW) layer; and a second semiconductor layer being a p-GaN based compound semiconductor formed over said light generating layer; a Ni/Au layer formed over said second semiconductor layer; a light extraction layer being a doped metal oxide transmissible to light and formed over said second semiconductor layer and comprising a III-group element doped ZnO based layer and having a thickness of at least 1 μm; an n-type metal electrode disposed over an exposing region of said first semiconductor layer; and a p-type metal electrode disposed over said light extraction layer.