First demonstration of robust tri-gate β -Ga2O3 nano-membrane field-effect transistors.

Nano-membrane tri-gate β -gallium oxide (β -Ga₂O₃) field-effect transistors (FETs) on SiO₂/Si substrate fabricated via exfoliation have been demonstrated for the first time. By employing electron beam lithography, the minimum-sized features can be defined with the footprint channel width of 50 nm. For high-quality interface between β -Ga₂O₃ and gate dielectric, atomic layer-deposited 15 nm thick aluminum oxide (Al₂O₃) was utilized with tri-methyl-aluminum (TMA) self-cleaning surface treatment. The fabricated devices demonstrate extremely low subthreshold slope (SS) of 61 mV dec^âˆ'1, high drain current (I _DS) ON/OFF ratio of 1.5 × 10⁹, and negligible transfer characteristic hysteresis. We also experimentally demonstrated robustness of these devices with currentâ€"voltage (I â€" V) characteristics measured at temperatures up to 400 °C. [ABSTRACT FROM AUTHOR]