Composition and Properties Control Growth of High-Quality GaO_xN_y Film by One-Step Plasma-Enhanced Atomic Layer Deposition

This study provided a novel method for depositing high-quality GaOxNy film by plasma-enhanced atomic layer deposition (ALD). To obtain a uniform nitrogen and oxygen composition, O2 and NH3 were led into the ALD chamber at the same time. It was found that the growth rate, composition, and optical properties of the GaOxNy film could be precisely controlled by adjusting the O2:NH3 ratio. The energy band gap was well tuned from 3.46 to 4.78 eV with increased O2 ratios. The detailed analysis of the X-ray photoelectron spectra proved the existence of Ga–O, Ga–N, and N–Ga–O bonds in prepared GaOxNy film. The surface, interface, and construction of the GaOxNy films were different with GaN and Ga2O3 films through transmission electron microscope characterization. Then a possible growth mechanism was demonstrated based on these findings. The energy band structure of all GaOxNy films deposited in this study was obtained from a detailed analysis of the valence band spectra. Importantly, the GaOxNy was found to exhibit lower leakage current and higher breakdown voltage than both GaN and Ga2O3. These findings offered a foundation and proved this material will present brilliant application prospects in photodetection, photoelectrochemical water splitting, and high-voltage devices.