SEMICONDUCTOR BASE MATERIAL AND METHOD OF MANUFACTURING THE MATERIAL

摘要

A semiconductor base material, comprising a substrate (1) having an irregula r epitaxial growth surface shown in Fig. 1 (a), wherein, when the vapor phase epitaxial growth of GaN crystals is performed, the irregular surface suppresses a lateral growth and promotes a growth in C-axis direction so as to form a base surface allowing a facet surface to be formed thereon and, as shown in Fig. 1 (b), the crystals having the facet surface formed thereon gr ow on projected parts and also on recessed parts and, when the crystal growth i s further performed, the films grown from the projected and recessed parts are connected to each other to eventually cover the irregular surface as shown i n Fig. 1 (c) for flattening and, in this case, and area with low dislocation density is formed at the top parts of the projected parts having the facet surface formed thereon to increase the quality of the film.