Patent ID: 8476158

Claim:
A GaN substrate preparation and storage method comprising: a substrate-preparation step of preparing a GaN substrate, defining first and second principal faces as distinct from the substrate edge, so as to have a planar first principal face and a plane orientation, in an arbitrary point along the first principal face and separated 3 mm or more from the outer edge thereof, having an off-inclination angle of between −10° and 10°, inclusive, with respect to the plane orientation of an arbitrarily designated crystalline plane that is inclined between 50° and 90°, inclusive, with respect to a plane, being either the (0001) plane or the (000 1 ) plane, through the arbitrary point; a storage-atmosphere preparation step of preparing a GaN-substrate storage atmosphere of not greater than 15 vol. % oxygen concentration and not greater than 20 g/m 3 water-vapor concentration; and a storage step of storing the prepared GaN substrate within the atmosphere prepared in said storage-atmosphere preparation step.