METHOD FOR MAKING NITRIDE SEMICONDUCTOR SUBSTRATE AND METHOD FOR MAKING NITRIDE SEMICONDUCTOR DEVICE

摘要

On a sapphire base (701), a GaN layer (702) and a substrate separating layer (703) are sequentially deposited, and the GaN layer (702) and the substrate separating layer (703) are processed to have a plurality of ridge stripes (702a) and recess portions (702b). Subsequently, a GaN based semiconductor layer (706) is grown on a C surface (703c) of the substrate separating layer (703) exposed on top of ridge stripes (702a) as seed crystal. The C surface (703c) of the substrate separating layer (703) is irradiated with a laser beam (802) to remove the substrate separating layer (703), thereby separating the GaN based semiconductor layer (706) from the sapphire base (701).