[TuP3G] Oxide Materials & Devices

[TuP3G-02] Role of Oxygen Supply in Stabilizing Epitaxial β-Ga₂O₃ Growth on Sapphire Substrates

〇Wei-Chun Chen¹, Wei-Lin Wang¹, Kun-An Chiu¹, Hung-Pin Chen¹, Hui-Wen Chang¹, Yu-Wei Lin¹ (1. National Center for Instrumentation Res., National Inst. of Applied Res. (Taiwan))

High-quality epitaxial beta-Ga₂O₃ thin films were grown on c-plane Al₂O₃ substrates by MOCVD. The effect of the O₂/Ga supply ratio on phase formation, crystalline orientation, and surface morphology was systematically investigated. X-ray diffraction and electron microscopy confirm monoclinic beta-phase growth with a preferred <−201> orientation. Increasing the O₂/Ga ratio enhances epitaxial uniformity and promotes a transition from faceted grains to compact columnar structures. These results indicate that oxygen chemical potential plays a key role in controlling nucleation behavior, growth kinetics, and crystalline quality of beta-Ga₂O₃ films on sapphire substrates.