Patent ID: 8519416

Claim:
A nitride-based semiconductor light-emitting device comprising: a nitride-based semiconductor substrate; a first region provided on said nitride-based semiconductor substrate and a second region arranged to be adjacent to said first region through a step portion having a prescribed height; and a nitride-based semiconductor layer formed on an upper surface of said first region of said nitride-based semiconductor substrate and a side surface of said step portion, wherein said nitride-based semiconductor layer includes a first conductive type cladding layer, an active layer and a second conductive type cladding layer successively formed from a side closer to said nitride-based semiconductor substrate, said first conductive type cladding layer has a different composition from said nitride-based semiconductor substrate as well as contains Al, Ga and N; and an Al composition ratio of said first conductive type cladding layer formed on the side surface of said step portion is lower than an Al composition ratio of said first conductive type cladding layer formed on the upper surface of said first region, and the upper surface of said first region of said nitride-based semiconductor substrate has a (H,K,-H-K,L) plane wherein H and K are integers, and at least either H or K is nonzero, wherein L is any number that allows the Al composition ratio of said first conductive type cladding layer formed on the side surface of said step portion to be lower than the Al composition ratio of said first conductive type cladding layer formed on the upper surface of said first region, wherein the first conductive type cladding layer comprises a single layer having an Al composition ratio in a portion of the single layer formed on the side surface of the step portion lower than an Al composition ratio in another portion of the corresponding single layer formed on the upper surface of said first region, wherein a thickness of the portion of the single layer formed on the side surface of the step portion is smaller than a thickness of the another portion of the corresponding single layer formed on the upper surface of the first region.