Metal oxide catalyzed epitaxy (MOCATAXY) of β -Ga2O3 films in various orientations grown by plasma-assisted molecular beam epitaxy

Abstract

In this work, the growth of (010), (001), and 2̄01 β-Ga2O3 by plasma assisted molecular beam epitaxy was investigated. The presence of an indium flux during growth markedly expands the growth regime for β-Ga2O3 across all orientations to higher growth temperatures and growth rates. This metal oxide catalyzed growth allows for similar growth rates of around 5 nm/min across all three orientations, more than twice that of conventional (010) growth and seven times that of (001) growth without indium. Smooth surface morphologies for (010) and (001) β-Ga2O3 were demonstrated, while 2̄01 was significantly rougher. Additionally, doping with Sn was achieved across all orientations and Hall measurements demonstrated higher electron mobility (55 cm2/Vs for a carrier concentration of 3.3 × 1018 cm-3) for (001) β-Ga2O3 grown via metal oxide catalyzed epitaxy than conventional growth.