Method of manufacturing a self-supporting substrate

PROBLEM TO BE SOLVED: To provide a method for manufacturing a free-standing substrate, capable of easily peeling from a base substrate by a simple process and manufacturing a group III nitride semiconductor free-standing substrate having comparatively excellent crystallinity at a low cost.SOLUTION: The method for manufacturing a free-standing substrate, capable of manufacturing the free-standing substrate consisting of a group III nitride semiconductor comprises: epitaxially growing a low-temperature buffer layer consisting of a group III nitride semiconductor layer at a growth temperature of 400-600°C with a thickness of 80-1000 nm on a substrate; epitaxially growing a group III nitride semiconductor layer at a temperature higher than the growth temperature of the low-temperature buffer layer on the grown low-temperature buffer layer; and manufacturing the free-standing substrate consisting of a group III nitride semiconductor grown at the high temperature by peeling the group III nitride semiconductor layer grown at the high temperature from the substrate.SELECTED DRAWING: Figure 1