Patent ID: 8847256

Claim:
A light emitting device comprising: a substrate; an undoped semiconductor layer on the substrate; a first conductive type semiconductor layer on the undoped semiconductor layer, wherein the first conductive type semiconductor layer includes a first layer on the undoped semiconductor layer and a second layer on the first layer, wherein an upper surface of the first layer includes a first upper surface and a second upper surface and the second layer is disposed on the first upper surface of the first layer; an active layer on the second layer of the first conductive type semiconductor layer; a second conductive type semiconductor layer on the active layer; and a plurality of vacant space parts disposed between the first upper surface of the first layer and the second layer, wherein each of the plurality of vacant space parts has a thickness less than that of the second layer of the first semiconductor layer, wherein a bottom surface of the second layer is contacted with the first upper surface of the first layer in between the plurality of vacant space parts, and wherein the second upper surface of the first layer is exposed outside.