This letter proposes a hybrid abrupt switch principle and a corresponding device architecture that combines quantum mechanical band-to-band and barrier tunneling mechanisms. The device overcomes the intrinsically low on-current (I-ON) of conventional tunnel field-effect transistors (TFETs) and the 60 mV/dec subthreshold swing limitation of metal-oxide-semiconductor FETs at room temperature. The device principle and characteristics are studied through two-dimensional numerical simulations. The predicted performance of such hybrid TFET architecture, implementing an ultrathin (0.5 nm) tunneling dielectric between metal source and silicon channel are: average SS values as low as 43 mV/dec, I(ON similar to)49.3 mu A/mu m, and I-ON/I(OFF similar to)10(7). (c) 2011 American Institute of Physics. [doi:10.1063/1.3569760]