β-Ga2O3 MOSFETs for Radio Frequency Operation

We demonstrate a beta-Ga2O3 MOSFET with record-high transconductance (g(m)) of 21 mS/mm and extrinsic cutoff frequency (f(T)) and maximum oscillating frequency (f(max)) 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 P-OUT, 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 beta-Ga2O3.