▎ 摘　　要

In this paper, we investigate the performance potentials of silicon nanowire (SNW) and semiconducting graphene nanoribbon (GNR) MOSFETs by using first-principles bandstructures and ballistic current estimation based on the "top-of-the-barrier" model. As a result, we found that SNW-MOSFETs display a strong orientation dependence via the atomistic bandstructure effects, and [110]-oriented SNW-MOSFETs provide smaller intrinsic device delays than Si ultrathin-body MOSFETs when the wire size is scaled smaller than 3 nm. Furthermore, GNR-MOSFETs are found to exhibit promising device performance if the ribbon width is designed to be larger than a few nanometers and a finite band gap can be established.