Low-Temperature Homoepitaxial Growth of Gan Using Hyperthermal Molecular Beams

Abstract

ABSTRACTIn situ cleaning of MOCVD-grown GaN/AlN/6H-SiC substrates using NH3-seeded supersonic molecular beams was investigated. Removal of surface carbon and oxygen contaminants was achieved by heating at 730°C under a hyperthermal NH 3 beam. Oxygen is removed primarily by thermal desorption; however, carbon removal requires an NH3 flux. Atomically smooth surfaces with regular steps are obtained after NH3 beam cleaning. Homoepitaxial growth of smooth, highly textured GaN films was accomplished at 700°C by employing a 0.61-eV NH3 beam and an effusive Ga source.