Processing of 50 nm gate-length hydrogen terminated diamond FETs for high frequency and high power applications

Abstract

To better understand the intrinsic scaling limitations of sub-100nm gate-length hydrogen-terminated diamond Field Effect Transistors (FETs), the fabrication and DC characterisation of 50nm gate length devices have been investigated. Physical processing of the hydrogenated diamond surface presents a challenge for the realisation of short gate length, high performance devices due to the inherent sensitivity of the surface to device processing. Through the development of a finely optimised device fabrication process, we have demonstrated transistor operation at a reduced gate length of 50nm. This is believed to be the shortest gate length operational diamond transistor yet reported. Inspection of device operation at larger voltages indicates the onset of potential short channel effects, attributed to the reduced dimensions of the gate. This is an important result in the investigation of the high frequency and high power potential of hydrogen terminated diamond transistors.