Scaling of Hydrogen-Terminated Diamond FETs to Sub-100-nm Gate Dimensions

We present the dc operation of hydrogen-terminated diamond field-effect transistors (FETs) with gate lengths of 1 μm to 50 nm. The 50-nm device metrics include a maximum drain current of 290 mA/mm and a peak extrinsic transconductance of 95 mS/mm. As the device gate length is reduced, peak intrinsic transconductance is increased substantially to a value of 650 mS/mm for the 50-nm device. A minimum I_on/I_off ratio of ~ 1.5 × 10⁴ is maintained at this reduced gate dimension. These results appear highly promising for the improvement of hydrogen-terminated diamond FET high-frequency performance through reduction of the device gate length to sub-100-nm dimensions.