Patent ID: 7655960

Claim:
An aluminum indium gallium nitride (Al x In y Ga 1−x−y N: 0≦x≦1, 0≦y≦1, 0<x+y≦1) mixture crystal substrate having a top surface and a bottom surface, comprising: a closed defect accumulating region (H) including a core (S) penetrating the substrate and containing many accumulated defects and a grain boundary (K) enclosing the core (S); an accompanying low dislocation single crystal region (Z) surrounding the closed defect accumulating region (H) and being a single crystal of a basic orientation with low dislocation density; and an extra low dislocation single crystal regions (Y) lying outside of the accompanying low dislocation single crystal region (Z) and being a single crystal with the same basic orientation as the accompanying low dislocation single crystal regions (Z).