Metal–organic chemical vapor deposition of ε-Ga2O3 thin film using N2O as a precursor

Abstract

As a novel wide bandgap semiconductor, ε phase Ga₂O₃ is characterized by an extremely high polarization coefficient and could be applied in different kinds of piezoelectric or electronic devices. However, to date, the growth technologies of ε-Ga₂O₃ have been so limited that high quality ε-Ga₂O₃ is still unavailable. In this work, ε-Ga₂O₃ thin films were grown on c-plane sapphire substrates by metal–organic chemical vapor deposition (MOCVD) using a two-step method. The effect of using N₂O as an oxygen precursor for the epitaxial growth of ε-Ga₂O₃ is investigated. The phase purity and growth mode of Ga₂O₃ thin films are investigated for samples prepared under different conditions. Phase transition takes place depending on the VI/III ratio, which is explained by the interplay of thermodynamic and kinetic effects. At a growth temperature of 600 °C, the full width at half maximum (FWHM) of the ε-Ga₂O₃ (004) plane rocking curve is as low as 0.20°, demonstrating that N₂O could be a potential precursor for the MOCVD growth of ε-Ga₂O₃.