$\beta$ -Ga2O3 MOSFETs for Radio Frequency Operation

We demonstrate a β-Ga ₂ O ₃ MOSFET with record-high transconductance (gm) of 21 mS/mm and extrinsic cutoff frequency (fT) and maximum oscillating frequency (fmax) of 3.3 and 12.9 GHz, respectively, enabled by implementing a new highly doped ohmic cap layer with a sub-micron gate recess process. RF performance was further verified by CW Class-A power measurements with passive source and load tuning at 800 MHz, resulting in POUT, power gain, and power-added efficiency of 0.23 W/mm, 5.1 dB, and 6.3%, respectively. These preliminary results indicate potential for monolithic or heterogeneous integration of power switch and RF devices using β-Ga ₂ O ₃ .