| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method of obtaining a large-area GaN crystal self-standing substrate which has a smooth surface having a small dark-point density, a thickness of 0.2-5 mm and an RMS of an as-grown crystal surface of smaller than 300 nm and a nonpolar or semipolar orientation, at low costs by a simple operation without deterioration of crystal quality.SOLUTION: A method of producing a gallium nitride crystal self-standing substrate which has a semipolar principal plane, e.g. the {11-22} plane, or a nonpolar principal plane, e.g. the {11-20} plane by growing a gallium nitride crystal layer on a sapphire ground substrate formed with a plurality of grooves which has side walls inclined to the principal plane of the ground substrate comprises forming a gallium nitride crystal layer of a thickness of 0.05-5μm having a semipolar or nonpolar principal plane on the sapphire ground substrate by the MOVPE method, masking the surface partially, forming a gallium nitride crystal layer of a thickness of 0.2-5 mm having a semipolar or nonpolar principal plane by the HVPE method and separating the sapphire ground substrate.</p> |
