Preparation of amorphous gallium oxide films

Abstract

Amorphous gallium oxide (a-Ga2O3) films were successfully fabricated on Al2O3 substrates via radio frequency (RF) magnetron sputtering under room temperature conditions. The preparation process was systematically optimized, including substrate cleaning, vacuum environment control, and sputtering parameter regulation (140 W power, 1 Pa pressure, 5 r/min substrate rotation speed). The structural, morphological, and optical properties of the as-prepared films were comprehensively characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible spectrophotometry. XRD results confirmed the amorphous nature of the films, as no distinct Ga2O3 diffraction peaks were detected. SEM images revealed that the films were continuous, uniform, and dense with a thickness of approximately 703 nm, exhibiting excellent adhesion to the substrate. Optical characterization indicated a steep absorption edge at 270 nm, with strong absorption in the ultraviolet (UV) region (<300 nm) and high transmittance (>85%) in the visible region. These findings demonstrate that RF magnetron sputtering is a reliable and scalable method for preparing high-quality a-Ga2O3 films, which hold great potential for applications in solar-blind UV photodetectors and transparent optoelectronic devices.