Patent ID: 7176497

Claim:
A group III nitride compound semiconductor comprising: a substrate; a first group III nitride compound semiconductor layer Al x1 Ga y1 In 1-x1-y1 N (0≦x1≦1, 0≦y1≦1, 0≦x1+y1≦1) formed on said substrate into an island pattern including at least one of a dot pattern, a striped pattern, and a grid pattern such that substrate-exposed portions are formed in a scattered manner; and a second group III nitride compound semiconductor layer Al x2 Ga y2 In 1-x2-y2 N(0≦x2≦1, 0≦y2≦1, 0≦x2+y2≦1) which causes epitaxial growth from an island or islands of said first group III nitride compound semiconductor serving as nuclei so that said second group III nitride compound semiconductor keeps an empty gap to said substrate-exposed portions and connects adjacent ones of said first group III nitride compound semiconductor.