Gallium nitride crystal substrate and method of producing same

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
• random defect bundle regions (G) of densities between 0/cm2 and 100/cm2.

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);
• and
• 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);
• characterized in that a distortion curvature radius of the gallium nitride crystal substrate is from 150 cm to 1800 cm.