Direct measurements of frequency response of carbon nanotube field effect transistors

The frequency response of a carbon nanotube field effect transistor (CNFET) biased in the common-source and common-gate configurations has been measured up to 200 MHz for the first time using a direct measurement technique. In this frequency range there is no observed degradation in the measured AC response of the CNFET. The effect of parasitic capacitance on the measurement has been identified and based on a simple model; it is estimated that this approach can be extended well into the Gigahertz range. This is the only demonstrated method of directly characterising the frequency response of nanoscale devices where the signal levels are below the noise floor of conventional network analysers.