METHOD OF FABRICATING GaN SINGLE-CRYSTAL SUBSTRATE FOR REDUCING GENERATION OF STRESS DUE TO DIFFERENCE BETWEEN THERMAL EXPANSION COEFFICIENTS BY REDUCING CONTACT AREA BETWEEN GaN SINGLE-CRYSTAL GROWTH SUBSTRATE AND GaN SINGLE-CRYSTAL BULK

摘要

PURPOSE: A method of fabricating a GaN single-crystal substrate is provided to reduce generation of stress due to a difference between thermal expansion coefficients by reducing a contact area between a GaN single-crystal growth substrate and a GaN single-crystal bulk. CONSTITUTION: A GaN single-crystal bulk(25) is formed on an upper surface of a GaN single-crystal growth substrate(21). A plurality of grooves having a predetermined width are formed on the GaN single-crystal growth substrate in order to divide the GaN single-crystal growth substrate into plural GaN single-crystal growth substrates. The GaN single-crystal bulk is separated from the GaN single-crystal growth substrate by irradiating a bottom face of the GaN single-crystal growth substrate.