Hexagonal phase-pure wide band gap ε-Ga2O3 films grown on 6H-SiC substrates by metal organic chemical vapor deposition

Abstract

In this paper, hexagonal structure phase-pure wide-band gap ε-Ga2O3 films were grown by metal organic chemical vapor deposition on 6H-SiC substrates. The ε-Ga2O3 films with good crystal quality were verified by high-resolution X-ray diffraction. The out-of-plane epitaxial relationship between ε-Ga2O3 films and 6H-SiC substrates is confirmed to be ε-Ga2O3 (0001)//6H-SiC (0001), and the in-plane epitaxial relationship is also confirmed to be ε-Ga2O3 ⟨112¯0⟩//6H-SiC ⟨112¯0⟩. The SEM and AFM images show that the ε-Ga2O3 films are uniform and flat. The ε-Ga2O3 films are thermally stable up to approximately 800 °C and begin to transform into β-phase Ga2O3 at 850 °C. Then, they are completely converted to β-Ga2O3 films under 900 °C. The high-quality ε-Ga2O3 films with hexagonal structure have potential application in the optoelectronic field.