PRESERVATION METHOD OF GaN SUBSTRATE, PRESERVED SUBSTRATE, SEMICONDUCTOR DEVICE, AND MANUFACTURING METHOD FOR THEM

摘要

PROBLEM TO BE SOLVED: To provide a preservation method of a GaN substrate capable of manufacturing a semiconductor device having superior characteristics, a preserved substrate and a semiconductor device, and to provide a manufacturing method for them. SOLUTION: This preservation method of a GaN substrate preserves the GaN substrate 1, in an atmosphere where oxygen concentration is 18 vol.% and/or steam concentration is below 25 g/m3. In this case, both the surface roughness Ra of a first principal surface of the GaN substrate and the surface roughness Ra of a second principal surface thereof can be set as not larger than 20 nm. The off-angle formed by a principal surface of the GaN substrate and the (0001) plane can be set at 0.05-2°in the <1-100> orientation, and 0-1°in the <11-20> orientation. COPYRIGHT: (C)2009,JPO&INPIT