Influence of Nitrogen Annealing Treatment on Optical, Microstructural, and Chemical Properties of Ga2O3 Film Grown by Plasma-Enhanced Atomic Layer Deposition

Inthis paper, high-quality beta-Ga2O3 filmswere grown on silicon substrates by plasma-enhancedatomiclayer deposition (PEALD). Effects of annealing temperature on beta-Ga2O3 thin films were studied. Atomic force microscopy(AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS),X-ray reflection (XRR), and ultraviolet (UV) emission spectroscopywere used to systematically characterize Ga2O3 thin films. AFM test results showed that as annealing temperatureincreased from 500 to 900 degrees C, the roughness of film increasedfrom 0.542 to 1.58 nm. XPS test results showed that the concentrationof oxygen vacancies in annealed films was significantly reduced. Afterannealing, the energy band of the film increased from 4.73 to 5.01eV, and the valence band maximum (VBM) increased from 2.58 to 2.67eV, indicating that the annealing treatment under a nitrogen atmospherecan improve the quality of films. Results demonstrate that high-qualityGa(2)O(3) films can be obtained by the annealingprocess after atomic layer deposition (ALD). The proposed method canrealize an ideal stoichiometric ratio of the Ga2O3 thin film as well as precise control of its optical, electrical,and microstructural properties. This work lays the foundation forfuture application of Ga2O3 materials in photoelectricdetection, power devices, transparent electronics, and other fields.