GaN substrate manufacturing method, GaN substrate, and semiconductor device

摘要

A GaN substrate manufacturing method characterized in including a step of processing the surface of a substrate composed of a GaN single crystal into a concavely spherical form, based on differences in orientation of the crystallographic axis across the substrate surface. Processing the GaN substrate surface into a concavely spherical form reduces, in the post-process GaN substrate surface, differences in orientation of the crystallographic axis with respect to a normal. Furthermore, employing to manufacture semiconductor devices a GaN substrate in which differences in orientation of the crystallographic axis have been reduced makes it possible to uniformize in device characteristics a plurality of semiconductor devices fabricated from a single GaN substrate, which contributes to improving yields in manufacturing the semiconductor devices.