High Performance ${\beta}$ -Ga 2 O 3 Nano-Membrane Field Effect Transistors on a High Thermal Conductivity Diamond Substrate

Abstract

To suppress severe self-heating under high power density, we herein demonstrate top-gate nano-membrane β-gallium oxide (β-Ga 2 O 3) field effect transistors on a high thermal conductivity diamond substrate. The devices exhibit enhanced performance, with a record high maximum drain current of 980 mA/mm for top-gate β-Ga 2 O 3 field effect transistors and 60% less temperature increase from reduced self-heating, compared to the device on a sapphire substrate operating under identical power density. With improved heat dissipation, β-Ga 2 O 3 field effect transistors on a diamond substrate are validated using an ultrafast high-resolution thermoreflectance imaging technique, Raman thermography, and thermal simulations. INDEX TERMS β-Ga 2 O 3 FET, diamond, nano-membrane, thermal conductivity, self-heating effect.