Phase Control of Ga₂O₃ Thin Films Grown by Metal-Organic Chemical Vapor Deposition

Abstract

In this paper, Ga 2 O 3 thin films were grown on c- plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD). There was phase transition for samples grown with different flow rates of triethyl-gallium (TEGa) and deionized water (H 2 O). It is found that ε-Ga 2 O 3 is difficult to coalesce and the phase mixture by β­Ga 2 O 3 takes place if the flow rates of TEGa and H 2 O are too high. However, by using multiple-step growth method, the film became fully coalesced. High-quality ε-Ga 2 O 3 thin film with atomically flat surface and multilayer morphology was obtained.