High Performance Depletion/Enhancement-Mode beta-Ga2O3 on Insulator (GOOI) Field-effect Transistors with Record Drain Currents of 600/450 mA/mm

TL;DR

This paper reports on high-performance beta-Ga2O3 on insulator FETs achieving record drain currents of 600/450 mA/mm, with excellent electrical characteristics and potential for power device applications.

Contribution

The study demonstrates record high drain currents in beta-Ga2O3 on insulator FETs and shows how to modulate threshold voltage and achieve enhancement mode operation.

Findings

Record drain currents of 600/450 mA/mm for D/E-mode GOOI FETs.

High on/off ratio of 10^10 and low subthreshold swing of 140 mV/dec.

E-mode GOOI FET with 185 V breakdown voltage.

Abstract

In this letter, we report on high performance depletion/enhancement (D/E)-mode beta-Ga2O3 on insulator (GOOI) field-effect transistors (FETs) with record high drain currents (ID) of 600/450 mA/mm, which are nearly one order of magnitude higher than any other reported ID values. The threshold voltage (VT) can be modulated by varying the thickness of the beta-Ga2O3 films and the E-mode GOOI FET can be simply achieved by shrinking the beta-Ga2O3 film thickness. Benefiting from the good interface between beta-Ga2O3 and SiO2 and wide bandgap of beta-Ga2O3, a negligible transfer characteristic hysteresis, high ID on/off ratio of 10^10, and low subthreshold swing of 140 mV/dec for a 300 nm thick SiO2 are observed. E-mode GOOI FET with source to drain spacing of 0.9 um demonstrates a breakdown voltage of 185 V and an average electric field (E) of 2 MV/cm, showing the great promise of GOOI FET for future power devices.