Hydrogen-Terminated Diamond Field-Effect Transistors With Cutoff Frequency of 53 GHz

Homoepitaxial diamond has been used to demonstrate the RF performance of 50-nm gate length hydrogen-terminated diamond field-effect transistors. An extrinsic cutoff frequency of 53 GHz is achieved which we believe to be the highest value reported for a diamond-based transistor. The generation of an RF small signal equivalent circuit is used to extract device elements to better understand variation between intrinsic and extrinsic operation. An intrinsic cutoff frequency of 90 GHz is extracted through this process, verifying the requirement to minimize access resistance to maximize the potential high-frequency performance of this technology.