Patent ID: 7084421

Claim:
A light-emitting semiconductor device comprising: a substrate; plural semiconductor layers which are made of group III nitride group compound semiconductor formed on said substrate; and an active layer comprising a multiple quantum well structure comprising: a plurality of quantum well layers which satisfy the formula Al 1-x In x N, where a composition ratio x of indium (In) is in a range of where 0.15<x<0.6; and at least one quantum barrier layer which satisfies the formula Al 1-x-y Ga y In g N (0≦y≦1, 0≦z<1, 0≦z+y≦1), alternately formed with said plurality of quantum well layers, wherein a composition ratio y of gallium (Ga) in said at least one quantum barrier layer is one of y=1, y≈1, and 0.9<y≦1, and wherein a thickness of said plurality of quantum well layers is in a range from 1 nm to 10 nm.