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 2X1014 or smaller per cm2 and the number of silicon atoms is 3X1013 or smaller per cm2. It has a surface (3) in which the number of silicon atoms is 3X1013 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 2X1014 or smaller per cm2 and which has a haze level of 5 ppm or less.