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

Abstract

In this paper, Ga 2 O 3 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 Ga 2 O 3 film to gradually transition from ε-Ga 2 O 3 to β-Ga 2 O 3 . The ε-Ga 2 O 3 film was thermally annealed at different temperatures. XRD revealed that the ε-Ga 2 O 3 was transformed into a β/ε-Ga 2 O 3 mixed crystal phase. Finally, Ga 2 O 3 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 Ga 2 O 3 film to gradually change from ε-Ga 2 O 3 to β-Ga 2 O 3 . Therefore, we obtained ε-Ga 2 O 3 and β-Ga 2 O 3 film at 400 °C, respectively. • Ga 2 O 3 thin films were deposited on sapphire substrates by metal-organic chemical vapor deposition (MOCVD). • The crystal phase and orientation conversion via adjusting the growth parameters and thermal annealing. • The increasing growth temperature promoted the Ga 2 O 3 film to gradually transition. • Thermal annealing makes the ε-Ga 2 O 3 film gradually transform into β/ε-Ga 2 O 3 . • The growth pressure and TEGa flow rate induced the Ga 2 O 3 film changed from ε-Ga 2 O 3 nucleation to β-Ga 2 O 3 .