EPITAXIAL GROUND SUBSTRATE AND EPITAXIAL SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide an epitaxial ground substrate for obtaining a novel epitaxial substrate with which the amount of warpage is suppressed, and to provide the epitaxial substrate obtained by utilizing this epitaxial ground substrate. SOLUTION: A group III nitride buffer film 2 of <=1×10<8> /cm<2> in spiral dislocation density containing at least Al is formed on the substrate 1 composed of a sapphire substrate, etc. A group III nitride ground surface film 3 is then formed on this group III nitride buffer film 2.