β-Ga₂O₃ on insulator field-effect transistors with drain currents exceeding 1.5 A/mm and their self-heating effect

We have demonstrated that depletion/enhancement-mode β-Ga₂O₃ on insulator field-effect transistors can achieve a record high drain current density of 1.5/1.0 A/mm by utilizing a highly doped β-Ga₂O₃ nano-membrane as the channel. β-Ga₂O₃ on insulator field-effect transistor (GOOI FET) shows a high on/off ratio of 10¹⁰ and low subthreshold slope of 150 mV/dec even with 300 nm thick SiO₂. The enhancement-mode GOOI FET is achieved through surface depletion. An ultra-fast, high resolution thermo-reflectance imaging technique is applied to study the self-heating effect by directly measuring the local surface temperature. High drain current, low R_c, and wide bandgap make the β-Ga₂O₃ on insulator field-effect transistor a promising candidate for future power electronics applications.