Patent ID: 7221037

Claim:
A Group III nitride substrate comprising: a substrate; a semiconductor layer formed on the substrate; and Group III nitride crystals formed on the semiconductor layer, wherein the semiconductor layer is formed of a semiconductor expressed by a composition formula of Al u Ga v In 1−u−v N (wherein 0≦u≦1 and 0≦v≦1), a surface of the semiconductor layer is a plane that is sloped in one direction and includes steps of (0001) planes arranged step-wise, the plane that is sloped in one direction and the (0001) planes form an angle of at least 0.05° therebetween, and the Group III nitride crystals formed on the semiconductor layer have variations in in-plane carrier concentration, the variations being within a range of one fifth to five times a carrier concentration mean value, and the Group III nitride crystals have a dislocation density of 1×10 2 cm −2 or lower.