Schottky-Barrier Carbon Nanotube Field-Effect Transistor Modeling

Abstract

The theoretical performance of carbon nanotube field-effect transistors (CNFETs) with Schottky barriers (SBs) is examined by means of a general ballistic model. A novel approach is used to treat the SBs at the metal-nanotube contacts as mesoscopic scatterers by modifying the distribution functions for carriers in the channel. Noticeable current reduction is observed compared to previous ballistic models without SBs. Evanescent-mode analysis is used to derive a scale length and the potential profile near the contacts for radially symmetric CNFET structures. Band-to-band tunneling current and ambipolar conduction are also treated. The effects of different device geometries and different nanotube chiralities on the drain-current are studied using this simple model. Quantum conductance degradation due to SBs is also observed