Research on the crystal phase and orientation of Ga2O3 Hetero-epitaxial film

Abstract In this paper, Ga2O3 films were deposited on sapphire substrates by metal-organic chemical vapor deposition (MOCVD), and we investigated the crystal phase and orientation conversion by changing the growth parameters and thermal annealing. The increasing growth temperature induced the Ga2O3 film to gradually transition from e-Ga2O3 to β-Ga2O3. The e-Ga2O3 film was thermally annealed at different temperatures. XRD revealed that the e-Ga2O3 was transformed into a β/e-Ga2O3 mixed crystal phase. Finally, Ga2O3 films were grown at 400 °C under different growth pressures and TEGa flow rates, and the increasing growth pressure or decreasing TEGa flow rate induced the Ga2O3 film to gradually change from e-Ga2O3 to β-Ga2O3. Therefore, we obtained e-Ga2O3 and β-Ga2O3 film at 400 °C, respectively.