Patent ID: 8541772

Claim:
A nitride semiconductor stacked structure having a first surface on which a semiconductor including In x Al y Ga 1-x-y N (0≦x≦1, 0≦y≦1, x+y≦1) can be stacked, the structure comprising: a substrate having a step portion, the step portion including an upper surface, a lower surface, and a side surface between the upper surface and the lower surface; a first buffer layer including In s Al t Ga 1-s-t N (0≦s≦0.05, 0≦t≦1) and covering the lower surface and the side surface; a first crystal layer provided on the first buffer layer, including In s Al t Ga 1-s-t N (0≦s≦0.05, 0≦t≦0.05), and having an upper surface provided above the upper surface of the substrate; a second buffer layer including In s Al t Ga 1-s-t N (0≦s≦0.05, 0≦t≦1) and continuously covering the upper surface of the first crystal layer and the upper surface of the substrate; and a second crystal layer covering the second buffer layer, including In s Al t Ga 1-s-t N (0≦s≦0.05, 0≦t≦0.05), and having the first surface.