First Demonstration of Robust Tri-Gate \b{eta}-Ga2O3 Nano-membrane Field-Effect Transistors Operated Up to 400 {\deg}C

TL;DR

This paper reports the first fabrication and demonstration of nano-membrane tri-gate beta-Ga2O3 FETs on SiO2/Si substrates, showing high performance and operation stability up to 400°C.

Contribution

It introduces a novel fabrication of tri-gate beta-Ga2O3 FETs with high-temperature robustness and detailed interface engineering.

Findings

Achieved subthreshold slope of 61 mV/dec

Demonstrated operation at temperatures up to 400°C

High ON/OFF current ratio of 1.5 x 10^9

Abstract

Nano-membrane tri-gate beta-gallium oxide (\b{eta}-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 a 50 nm fin structure. For high-quality interface between \b{eta}-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, high drain current (IDS) ON/OFF ratio of 1.5 X 109, and negligible transfer characteristic hysteresis. We also experimentally demonstrated robustness of these devices with current-voltage (I-V) characteristics measured at temperatures up to 400 {\deg}C.