Low-Temperature Behavior of Single-Wall Carbon Nanotube Gate-all-Around Field-Effect Transistors

This work explores the low-temperature performance of a field-effect transistor with a carbon nanotube as the active channel. The device topology is an ideal cylindrical gate-all-around with the nanotube coaxially aligned. The nanotube considered is a single-wall zigzag (49,0). Electron transport is modeled using Ensemble Monte Carlo (EMC) simulations coupled self-consistently with the electrostatic solver. The electrostatic solver solves Gauss Law in integral form. Electron scattering mechanisms include longitudinal acoustic and optical phonons and a single radial breathing mode phonon. A wide range of temperatures is considered – from 4K to 220K to determine the effects of temperature in relation to device size and dielectric on the electronic response. Both steady-state and device transient responses are explored. The device is seen to work very well across the wide range of temperatures explored, with differences in performance attributed to the differences in electron scattering rates for different temperatures. In all cases, electrons are found to deliver up to a fraction of a microwatt of power.