Influence of band structure on electron ballistic transport in silicon nanowire MOSFET’s: An atomistic study

This work investigates the conduction band structure of silicon nanowires, its dependence with the wire width and its influences on the electrical performances of Si nanowire-based MOSFET’s working in the ballistic regime. The energy dispersions relations for Si nanowires have been calculated using a sp3 tight-binding model and the ballistic response of n-channel devices with a 3D Poisson–Schrödinger solver considering a mode-space approach and open boundary conditions (NEGF formalism). Results are compared with data obtained considering the parabolic bulk effective mass approximation, highlighting in this last case the overestimation of the Ion current, up to 60% for the smallest (1.36 nm × 1.36 nm Si wire) devices.