Phonon-scattering effects in CNT-FETs with different dimensions and dielectric materials

摘要

The impact of acoustic and optical phonon scattering on the performance of CNT-FETs is investigated using a full-quantum transport model within the NEGF formalism. Different gate lengths, dielectric materials and chiralities are considered. It is shown that the use of a high-k dielectric improves the off-current limited by phonon-assisted band-to-band tunneling. The device scalability is demonstrated: with an oxide thickness of 1.5 nm, good performance metrics are obtained down to a gate length of 15 nm with SiO_2 and of 10 nm with HfO_2 as gate dielectrics.