Method of preparing and storing gan substrate, prepared and stored gan substrate, and semiconductor device and method of its manufacture

Abstract

A GaN substrate storage method of storing, within an atmosphere in which the oxygen concentration is not greater than 15 vol. % and the water-vapor concentration is not greater than 20 g/m, a GaN substrate () having a planar first principal face (), and whose plane orientation in an arbitrary point (P) along the first principal face () and separated 3 mm or more from the outer edge thereof has an off-inclination angle Δα of −10° or more, 10° or less with respect to the plane orientation of an arbitrarily designated crystalline plane () that is inclined 50° or more, 90° or less with respect to a plane (), being either the (0001) plane or the (000) plane, through the arbitrary point. In this way a method of storing GaN substrates whose principal-face plane orientation is other than (0001) or (000), with which semiconductor devices of favorable properties can be manufactured is made available.