Patent ID: 8748868

Claim:
A nitride semiconductor light emitting device comprising: a support substrate comprising a hexagonal gallium nitride semiconductor; a semiconductor region comprising an active layer, a first gallium nitride-based semiconductor layer, an electron block layer, and a second gallium nitride-based semiconductor layer, the semiconductor region being provided on a primary surface of the support substrate; and a p-type cladding layer provided on a primary surface of the semiconductor region, a c-axis of the hexagonal gallium nitride semiconductor being inclined to a predetermined direction with respect to a normal axis to the primary surface of the support substrate, the p-type cladding layer comprising AlGaN, the electron block layer comprising AlGaN, the first gallium nitride-based semiconductor layer being provided between the active layer and the electron block layer, the second gallium nitride-based semiconductor layer being provided between the p-type cladding layer and the electron block layer, a material of the second gallium nitride-based semiconductor layer being different from a material of the electron block layer, the material of the second gallium nitride-based semiconductor layer being different from a material of the p-type cladding layer, a bandgap of the first gallium nitride-based semiconductor layer being smaller than a bandgap of the electron block layer, the electron block layer is subject to tensile strain in the predetermined direction, the first gallium nitride-based semiconductor layer being subject to compressive strain in the predetermined direction, and a misfit dislocation density at an interface between the first gallium nitride-based semiconductor layer and the electron block layer being smaller than a misfit dislocation density at an interface between the second gallium nitride-based semiconductor layer and the p-type cladding layer.