| 摘要 |
<p>A GaN layer (31) is etched in an insular shape, such as a dot, stripe or lattice, to provide steps with the bottoms thereof serving as recesses in a base substrate (1). Then, GaN (32) is epitaxial-grown laterally with the top and side surfaces of the upper treads of steps as nuclei to thereby bury portions above the lower treads (recesses in the base substrate (1)) of the steps and then grow them upward. Portions above the laterally epitaxial-grown portions of the GaN (32) are defined as areas where the propagation of penetration dislocation of the GaN layer (31) is restrained. Then, the remaining portions of the GaN layer (31) are etched and removed together with the upper-layer GaN (32), and GaN (33) is laterally epitaxial-grown with the remaining top surfaces and side surfaces of the upper treads of the GaN layer (32) as nuclei to thereby provide a GaN substrate (30) having penetration dislocation significantly restrained. The GaN substrate (30) having a small contact surface (GaN layer (31)) with the base substrate (1) can be easily separated.</p> |
