Simulation of Carbon nanotube FETs including hot-phonon and self-heating effects

A comprehensive exploration of how phonon scattering affects carbon nanotube FET is presented in this work. A full band electron and phonon Boltzmann transport equation (BTE) coupled with heat equation is used for the first time to asses the transistor performance. Comparing with measured data for the metallic tube, the importance of hot-phonon effect is shown. The model is then applied to explore these effects in CNT MOSFETs. Under large gate bias, we show that, hot phonon effect reduces the on-current by 33%. From a full dynamic simulation, with idealized isothermal condition, the unity gain cut-off frequency of a 20nm gate length ballistic CNT MOSFET is estimated to be 1.26THz. The estimated cut-off frequency reduces to 550GHz with hot phonon effects. Device heating, is also examined. Due to small operating bias (0.5V) and lower current of a single tube, temperature rise of a single c tube is negligible.