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 GaO_xN_y 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 GaO_xN_y 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 GaO_xN_y film. The surface, interface, and construction of the GaO_xN_y 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 GaO_xN_y films deposited in this study was obtained from a detailed analysis of the valence band spectra. Importantly, the GaO_xN_y 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.