Patent ID: 9472623
Filing Date: 2016-10-18
CPC Classification: H01L

Claim Text:
1. A nitride semiconductor element, comprising: a Si substrate including a primary surface; a buffer layer comprised of an AlN layer formed on the primary surface of the Si substrate, and an AlGaN laminated structure formed by laminating multiple AlGaN layers on the AlN layer, the buffer layer having a primary surface which has a plane orientation that is a c plane; a GaN electron transfer layer formed on the AlGaN laminated structure; and an AlGaN electron supply layer formed on the GaN electron transfer layer, wherein the AlGaN laminated structure includes a reference AlGaN layer, and an AlGaN layer that is closer to the AlN layer, and the reference AlGaN layer has an Al component that is lower than that of the AlGaN layer that is closer to the AlN layer, and wherein the reference AlGaN layer has an a-axis average lattice constant, the AlGaN layer arranged in contact with a surface of the reference AlGaN layer has an a-axis in-plane lattice constant, wherein the surface of the reference AlGaN layer faces the AlN layer, and wherein the a-axis average lattice constant of the reference AlGaN layer is greater than the a-axis in-plane lattice constant of the AlGaN layer arranged in contact with the surface of the reference AlGaN layer, and lower than an original a-axis average lattice constant of the reference AlGaN layer.