Full-band atomistic study of source-to-drain tunneling in Si nanowire transistors

Abstract

Source-to-drain tunneling is investigated for Si triple-gate nanowire transistors. The full-band quantum transport problem is solved in an atomistic basis using the nearest-neighbor sp3d5s* tight-binding method. It is self-consistently coupled to the three-dimensional calculation of the electrostatic potential in the device using the finite element method. This procedure is applied to the computation of Id - Vgs transfer characteristics of transistors with different channel orientations such as [100], [110], [111], and [112] for gate lengths ranging from 4 nm to 13 nm. The subthreshold swing S is then extracted from the results to determine the scaling limit of nanowire transistors.