High-Frequency Capability of Schottky-Barrier Carbon Nanotube FETs

The high-frequency capability of carbon nanotube field-effect transistors is investigated by simulating the small-signal performance of a device with negative-barrier Schottky contacts for the source and drain, and with a small, ungated region of nanotube between the end contacts and the edge of the wrap-around gate electrode. The overall structure is shown to exhibit resonant behaviour, which leads to a significant bias dependence of the small-signal capacitances and transconductance. This could lead to high-frequency figures of merit (fT and fmax) in the terahertz regime.