Growth and Performance Enhancement of Sputtered ZnGa2O4 MOSFETs on Sapphire Substrates

Metal-oxide-semiconductor field-effect transistors (MOSFETs) based on wide-band-gap semiconductors have garnered significant attention for their potential in high-performance and energy-efficient electronic devices. In this study, we explore the low-temperature growth, characterization, and performance of ZnGa2O4 film based MOSFETs on sapphire substrates through the utilization of radio frequency (RF) magnetron sputtering. The characteristics of ZnGa2O4 films were meticulously investigated at various annealing temperatures, specifically 400, 600, and 900 degree celsius. Our findings revealed that the crystallinity of ZnGa2O4 films was notably superior at a low annealing temperature of 400 degree celsius. Subsequently, we fabricated MOSFET devices by patterning the ZnGa2O4 films to create gate, source, and drain regions using a conventional photolithography process. The electrical characteristics of the ZnGa2O4 MOSFETs were thoroughly examined, unveiling their operation in the depletion mode. These devices exhibited a threshold voltage of -5 V, a maximum drain current of 110 mA/mm, a remarkable high drain current on-off current ratio of 10(7), and an excellent breakdown voltage of 575 V, underlining their suitability for high-power applications. This research demonstrates the successful fabrication of ZnGa2O4 based depletion-mode MOSFETs using a sputtering technique, offering a pathway toward the development of next-generation electronic devices with enhanced performance.