Modeling source-drain tunneling in ultimately scaled III-V transistors

Intraband source-drain tunneling is predicted to limit leakage current in sub-10nm field-effect transistors (FETs). We use non-equilibrium Green's function simulations to study this effect in III-V multigate FETs and derive simple, accurate intraband tunneling formulas suitable for use in compact models or semiclassical device simulators. Band nonparabolicity effects are shown to be quantitatively important and incorporated using band gap scaling. We also supply a general subthreshold electrostatic model including source and drain depletion effects for analytical modeling. Our results enable rapid modeling and simulation of ultimately scaled III-V FETs for device evaluation and optimization. (C) 2015 AIP Publishing LLC.