Patent ID: 7772599

Claim:
A gallium-nitride-based semiconductor stacked structure comprising: a low-temperature-deposited buffer layer composed of a Group III nitride material that has been grown at low temperature and that includes a single-crystal layer in as-grown state, the single-crystal layer being present in the vicinity of a junction area that is in contact with a (0001) (c) plane of a sapphire substrate; an active layer composed of a gallium-nitride (GaN)-based semiconductor layer that is provided on the low-temperature-deposited buffer layer; and a thin-film layer provided between the low-temperature-deposited buffer layer and the active layer and composed of a GaN-based Group III nitride semiconductor containing indium or aluminum having a layer thickness of 2 nm to 100 nm; wherein the single-crystal layer included in the low-temperature-deposited buffer layer in as-grown state is composed of a hexagonal Al x Ga y N (0.5<X≦1, X+Y=1)crystal that contains aluminum in a predominant amount with respect to gallium such that a [2.−1.−1.0.] direction of the Al x Ga y N crystal orients along with a [2.−1.−1.0.] direction of the (0001) bottom plane of the sapphire substrate.