Optimization of Si-Doped β-Ga2O3 Ceramic Targets for High-Performance Thin-Film Deposition

To enhance the performance of β-Ga₂O₃ for high-power electronic and optoelectronic applications, this study aims to optimize ceramic sputtering targets by systematically investigating the effects of Si doping and sintering temperature on their structural as well as physical properties. The primary objective is to elucidate how variations in Si concentration and thermal treatment influence the density, crystallinity, and phase purity of β-Ga₂O₃ targets. β-Ga₂O₃ ceramic targets were prepared via a conventional solid-state reaction method using Si doping concentrations of 0.5, 1, 1.5 and 2 wt%, followed by sintering at temperatures ranging from 1300 °C to 1500 °C. Structural properties were examined using x-ray diffraction (XRD) to evaluate crystallinity and phase composition. Bulk density and contact angle measurements were performed to assess sintering behavior and densification. The targets’ physical properties were highly sensitive to both dopant concentration and sintering temperature. The target containing 1 wt% Si, sintered at 1500 °C, exhibited the most favorable characteristics, achieving a relative density of 93.2% with a crystallite size of 75 nm. XRD analysis showed effective minimization of residual Si-related impurity phases, suggesting successful substitutional incorporation of Si into the Ga₂O₃ lattice. These results demonstrate that precise control of dopant concentration and sintering parameters is essential for producing β-Ga₂O₃ ceramic targets with high density and phase purity. Such optimization offers a solid foundation for fabricating high-quality Si-doped β-Ga₂O₃ thin films, supporting the advancement of next-generation power and optoelectronic devices.