GaN SINGLE CRYSTAL SUBSTRATE, NITRIDE SEMICONDUCTOR EPITAXIAL SUBSTRATE, AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a GaN single crystal substrate capable of flattening the surface of an epitaxial layer and reducing crystal defects in the epitaxial layer, to provide a nitride compound semiconductor epitaxial substrate and to provide its manufacturing method. SOLUTION: Polished surface of the GaN single crystal substrate 11 is subjected to heat treatment at≥990°C and≤1,010°C substrate temperature in an atmosphere of a mixed gas containing at least a NH3gas and a plurality of holes 13 are formed on the surface. When a compound semiconductor layer 12 is epitaxially grown on the surface of the substrate 11 in an appropriate growing condition, the holes 13 on the surface of the substrate 11 are buried while propagation of through dislocation from the substrate 11 to the semiconductor layer 12 is suppressed and the surface of the substrate are flattened. COPYRIGHT: (C)2004,JPO