Nanowire Transistors with Bound-Charge Engineering

Low-dimensional electronic systems such as silicon nanowires exhibit weak screening which is detrimental to the performance and scalability of nanodevices, e.g., tunnel field-effect transistors. By atomistic quantum transport simulations, we show how bound charges can be engineered at interfaces of Si and low-κ oxides to strengthen screening. To avoid compromising gate control, low-κ and high-κ oxides are used in conjunction. In Si nanowire tunnel field-effect transistors, we demonstrate that bound charge engineering increases the on-state current by orders of magnitude, and the combination of oxides yields minimal subthreshold swing. We conclude that the proposed bound-charge engineering paves a way toward improved low-power transistors.