【Epitaxy Papers】Influence of annealing atmospheres on the band alignment of atomic layer deposited β-Ga₂O₃ films

      Researchers from the Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences have published a dissertation titled "Influence of annealing atmospheres on the band alignment of atomic layer deposited β-Ga₂O₃ films" in Materials Letters.

Abstract

      In our study, β-Ga₂O₃ thin films were deposited on sapphire (0001) by atomic layer deposition and annealed at 1000 °C under nitrogen (N₂), oxygen (O₂), and vacuum atmospheres. Results show that vacuum annealing partially reduced oxygen vacancies via thermal migration, yet residual defects remained. Nitrogen and oxygen annealing effectively filled and passivated vacancies, improving lattice order,with the N₂-annealed sample exhibiting the highest lattice oxygen ratio (O_L/(O_L + O_NL) = 77.26 %, O_L: lattice oxygen; O_NL: non-lattice oxygen), but introducing nitrogen doping and interstitial oxygen defects. Experimental measurements of band alignment and bandgap, combined with density functional theory simulations, revealed band shifts induced by defect states under different annealing atmospheres. This study innovatively proposes an “annealing atmosphere-defect state-band shift” model, establishing a theoretical foundation for defect engineering and process optimization.

DOI：

https://doi.org/10.1016/j.matlet.2025.139110