Patent ID: 9087890
Filing Date: 2015-07-21
Classification: H01L

Abstract:
1. A semiconductor device comprising: an active layer, which has a composition represented by the formula: a substrate containing GaN; and a buffer layer provided between the active layer and a face of the substrate, wherein the semiconductor device is operated by electrical current flowing through the active layer in a direction parallel to the face of the substrate, wherein the buffer layer has a composition represented by the formula: wherein the buffer layer has a band gap energy wider than that of the substrate and is lattice-matched to the substrate, wherein a composition ratio of Al and a composition ratio of In in the buffer layer change in a thickness direction such that the buffer layer is lattice-matched to the substrate, and wherein the composition ratio of Al changes due to a change in the composition ratio of In and the composition ratio of In changes due to a change in the composition ratio of Al.