GROUP III ELEMENT NITRIDE SUBSTRATE, SUBSTRATE WITH EPITAXIAL LAYER, PROCESSES FOR PRODUCING THESE, AND PROCESS FOR PRODUCING SEMICONDUCTOR ELEMENT

摘要

A Group III element nitride substrate on which an epitaxial layer of good quality can be grown; and a process for producing the substrate. The Group III element nitride substrate may be a GaN substrate (1) which satisfies any of the following requirements. It has a surface (3) in which the number of atoms constituting any acid substance(s) is 2×10¹⁴ or smaller per cm² and the number of silicon atoms is 3×10¹³ or smaller per cm². It has a surface (3) in which the number of silicon atoms is 3×10¹³ or smaller per cm² and which has a haze level of 5 ppm or less. It has a surface (3) in which the number of atoms constituting any acid substance(s) is 2×10¹⁴ or smaller per cm² and which has a haze level of 5 ppm or less.