1.1 A/mm ß-Ga2O3-on-SiC RF MOSFETs with 2.3 W/mm Pout and 30% PAE at 2 GHz and fT/fmax of 27.6/57 GHz

This work demonstrates for the first time the power performance of ß-Ga
2
O
3
RF transistors at 2-8 GHz with a record high output power density (P
out
) of 2.3 W/mm and a power-added efficiency (PAE) of 30% at 2 GHz. Such P
out
and PAE are 25 and 3 times of previous state-of-the-art ß-Ga
2
O
3
RF power devices at 2 GHz, respectively. In addition, the device shows a maximum on-current (I
D,max
) of 1.1 A/mm and a f
T
/f
max
of 27.6/57 GHz, all among the highest in ß-Ga
2
O
3
RF devices. Such RF performances are enabled by transferring a heavily-doped ß-Ga
2
O
3
channel to a SiC substrate, which significantly reduce the on-resistance and improve the heat dissipation, as well as deploying an insulated and recessed T- gate to simultaneously enhance the frequency performance and electric field management. These results indicate a remarkable progress in the field of ß-Ga
2
O
3
RF power devices and show the promise of ß-Ga
2
O
3
-on-SiC platform for high-power, high- frequency, high-efficiency RF applications.