Compound semiconductor device and method for manufacturing the same

摘要

A compound semiconductor device includes: a substrate; a GaN compound semiconductor multilayer structure disposed over the substrate; and a stress relief layer which is AlN-based and which is disposed between the substrate and the GaN compound semiconductor multilayer structure, wherein a surface of the stress relief layer that is in contact with the GaN compound semiconductor multilayer structure includes recesses that have a depth of 5 nm or more and that are formed at a number density of 2×1010 cm-2 or more.