β-Al2xGa2-2xO3 Thin Film Growth by Molecular Beam Epitaxy

beta-Al2xGa2-2xO3 alloy thin films were successfully grown on (100)-oriented beta-Ga2O3 single-crystal substrates by plasma-assisted molecular beam epitaxy. The films were grown almost coherently and maintained the beta-phase up to an Al content of x = 0.61. Below an Al content of about x = 0.4, step-flow growth was achieved, and carrier accumulation was observed at the heterointerface. These results encourage further research into beta-Al2xGa2-2xO3 thin films and associated devices, especially high-electron-mobility transistors for high-power applications. (C) 2009 The Japan Society of Applied Physics DOI: 10.1143/JJAP.48.070202