71 GHz-f<inf>max</inf> β-Ga<inf>2</inf>O<inf>3</inf>-on-SiC RF Power MOSFETs with Record P<inf>out</inf>=3.1 W/mm and PAE=50.8% at 2 GHz, P<inf>out</inf>= 2.3 W/mm at 4 GHz, and Low Microwave Noise Figure

Abstract

In this work, we demonstrate heavily-doped (8× 1018cm-3) and gate-recessed β-Ga2O3 RF power MOSFETs integrated on a high thermal conductivity SiC substrate to minimize self-heating effect (SHE), high on-resistance (Ron) and short-channel effect (SCE). As a result, β-Ga2O3-on-SiC RF power FETs achieve a record maximum oscillation frequency (fmax) of 71 GHz, output power density (Pout) of 3.1 W/mm and power added efficiency (PAE) of 50.8% at frequency (f) of 2 GHz and Pout=2.3 W/mm at f=4 GHz. In addition, this work for the first time studies the microwave noise performance of the β-Ga2O3 RF MOSFET at f range of 2-18 GHz with low minimum-noise figure (NFmin) of 1.6 dB at f=4 GHz. Remarkably, we have provided an effective route of oxide RF transistors for future high-f, high-power and low-noise RF power applications.