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 sp 3 tight-binding model and the ballistic response of n-channel devices with a 3D Poisson–Schrodinger 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 I on current, up to 60% for the smallest (1.36 nm × 1.36 nm Si wire) devices.