Patent ID: 7556687

Claim:
A gallium nitride crystal substrate comprising; low dislocation single crystal regions (Z) having a definite c-axis and a definite a-axis, C-plane growth regions (Y) having a c-axis and an a-axis parallel to the c-axis and the a-axis of the low dislocation single crystal regions (Z), voluminous defect accumulating regions (H) having a c-axis inverse to the c-axis of the low dislocation single crystal regions (Z) and an a-axis parallel with the a-axis of the low dislocation single crystal regions (Z), and 0.1/cm 2 to 10/cm 2 c-axis gross core regions (F) containing at least one crystal having a c-axis parallel to the c-axis of the low dislocation single crystal regions (Z) and an a-axis different from the a-axis of the low dislocation single crystal regions (Z).