Pulsed RF Power Measurements of Laterally Scaled Ga2O3 FETs

The power switching potential of Ga
2
O
3
has been well established in the last several years due to the material's high critical electric field
$(\mathrm{E}_{\mathrm{C}})$
strength. This allows for dramatic device scaling and operation at high voltage with reduced series resistance in power switching applications. The same argument applies for RF power amplification, where the high
$\mathrm{E}_{\mathrm{C}}$
of Ga
2
O
3
allows FETs to be scaled to smaller dimensions while operating at higher operating voltages than existing RF FETs. At the same time, ab initio calculations published in 2017 for velocity-field characteristics of Ga
2
O
3
indicate a peak electron velocity of
$2\mathrm{x}10^{7}$
cm/s which suggests the power-frequency product for Ga
2
O
3
is significantly greater than that of GaN. In 2017, the first demonstrated CW RF operation for Ga
2
O
3
FETs was in part limited by the thermal resistance and immaturity of heat extraction techniques to ~300 mW/mm. Since then, pulsed RF power measurement techniques have been implemented to accelerate electrical characterization of RF Ga
2
O
3
FETs. Pulsed RF output power
$> 500$
mW/mm has been measured at 1 GHz. Advances in laterally scaled devices and topology design to ensure electrons achieve saturated velocity in the channel will be discussed.