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.