Role of phonon scattering in carbon nanotube field-effect transistors

The role of phonon scattering in carbon nanotube field-effect transistors (CNTFETs) is explored by solving the Boltzmann transport equation using the Monte Carlo method. The results show that elastic scattering in a short-channel CNTFET has a small effect on the source-drain current due to the long elastic mean-free path (mfp) (∼1μm). If elastic scattering with a short mfp were to exist in a CNTFET, the on current would be severely degraded due to the one-dimensional channel geometry. At high drain bias, optical phonon scattering, which has a much shorter mfp (∼10nm), is expected to dominate, even in a short-channel CNTFET. We find, however, that inelastic optical scattering has a small effect in CNTFETs under modest gate bias.