A new approach to free-standing GaN using β-Ga2O3 as a substrate

Abstract

Hexagonal GaN (0001) has been grown by a pseudo-HVPE method on β-Ga₂O₃ (100) using an intermediate low-temperature buffer layer formed by in situ NH₃ treatment of β-Ga₂O₃ substrate. A simple method for self-separation of bulk GaN from the β-Ga₂O₃ substrate is reported. The structural properties of the GaN and GaN–β-Ga₂O₃ interface were investigated by high-resolution X-ray diffraction and electron microscopy techniques. GaN layers were deposited on β-Ga₂O₃ by using gallium cyanide as a transport agent for gallium and, NH₃ as a source of nitrogen. The properties of these layers are compared with those of samples grown on sapphire.