Patent ID: 8680537

Claim:
A nitride semiconductor element, comprising: a foundation layer including an AIN buffer layer, the foundation layer having a major surface; a functional layer including a nitride semiconductor; and a stacked body provided between the major surface and the functional layer, the stacked body including a first stacked intermediate layer including: a first GaN intermediate layer provided on the foundation layer; a first high Al composition layer of Al x1 Ga 1-x1 N (0<x1≦1) provided on the first GaN intermediate layer; and a first low Al composition layer of Al y1 Ga 1-y1 N (0<y1<1 and y1<x1) provided on the first high Al composition layer of Al x1 Ga 1-x1 N (0<x1≦1), a compressive strain being applied to the first low Al composition layer of Al y1 Ga 1-y1 N (0<y<1 and y1<x1), unstrained GaN having a first lattice spacing along a first axis parallel to the major surface, unstrained Al x1 Ga 1-x1 N (0<x1≦1) having a second lattice spacing along the first axis, the first high Al composition layer of Al x1 Ga 1-x1 N (0<x1≦1) having a third lattice spacing along the first axis, and an Al composition ratio of the first low Al composition layer of Al y1 Ga 1-y1 N (0<y1<1 and y1<x1) being not more than a ratio of an absolute value of a difference between the first lattice spacing and the third lattice spacing to an absolute value of a difference between the first lattice spacing and the second lattice spacing.