Method for forming gan semiconductor single crystal substrate and gan diode with the substrate

Abstract

Method for forming a single crystal GaN semiconductor substrate and a GaN diode with the substrate is disclosed which forms in a short time period, has a low crystal defect concentration and allows forming a size large enough to fabricate an optical device, the method including either the steps of fast growth of a GaN group material on an oxide substrate to a thickness without cracking and subjecting to mechanical polish to remove a portion of the oxide substrate, and growing GaN again on the grown GaN layer and complete removal of the remaining oxide substrate to obtain a GaN film, or the steps of separating the oxide substrate from the GaN layer utilizing cooling to obtain a GaN film, grown GaN on the GaN film to a predetermined thickness to form a GaN bulk single crystal and mirror polishing it to form the GaN single crystal substrate, whereby a defectless GaN single crystal substrate of a size required for fabrication of an optical device can be obtained within a short time period because fast homoeptaxial growth of a GaN film is allowed.