Patent ID: 7388268

Claim:
A compound semiconductor stacked structure having a first compound semiconductor layer, an active layer, and a second compound semiconductor layer, which are successively stacked on a substrate, wherein said active layer consists of a compound semiconductor with a composition represented by In x Ga 1-x ,As y Sb 1-y (0.8≦x≦1.0, 0.8≦y ≦1.0) and is thicker than 35 nm and thinner than 70 nm; said first and second compound semiconductor layers are each a compound semiconductor layer having Sb and at least two of five elements consisting of Al, Ga, In, As and P, and have a band gap greater than that of said active layer, and a resistance at least five times greater than that of said active layer; and lattice constant differences between said active layer and said first and second compound semiconductor layers are set within a range of 0.2% to 0.9%.