Suspended individual SWCNT characterization via bottom gate FET configuration

The microwave transmission properties of suspended, quasi-metallic individual single-walled carbon nanotubes (SWCNTs) with a bottom gate field-effect transistor (FET) configuration have been investigated up to 10 GHz by standard two-port S-parameter measurements under different gate bias voltages. A tapered coplanar waveguide (CPW) transmission-line test fixture is designed to overcome the parasitic and mismatch issues. An open-through de-embedding algorithm has been applied to extract the intrinsic properties of SWCNTs. And an equivalent circuit model has been proposed to fit the extracted measurement data as a function of the bottom gate bias voltage, facilitating the applications of CNTs into high-frequency nanocircuits. Moreover, the properties of our transistor device are found to change after a period of time.