METHOD FOR PRESERVING GaN SUBSTRATE, PRESERVED SUBSTRATE, SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD FOR SEMICONDUCTOR DEVICE

摘要

PPROBLEM TO BE SOLVED: To provide a method for preserving a GaN substrate capable of manufacturing the semiconductor device having satisfactory characteristics, the preserved substrate and the semiconductor device, and to provide a manufacturing method for the semiconductor device. PSOLUTION: The GaN substrate 1 is preserved, under an atmosphere having an oxygen concentration of 18 vol.% and/or a steam concentration of 12 g/mSP3/SPor less. The surface roughness Ra of the first main surface of the GaN substrate is set at 20 nm or smaller and that of the second main surface set to 20 μm or smaller. The off-angle, formed by the main surface of the GaN substrate and a (0001) face, is set at a value range of 0.05° to 2° in 1-100 orientation, and at a value from 0° to 1° in 11-20 orientation. PCOPYRIGHT: (C)2008,JPO&INPIT