In this work we report the main results of a research activity on a novel device concept which aims to achieve a steep switching behavior based on the filtering of high-energy electrons in the FET source region. The filtering function is entrusted to a superlattice in the source extension, which could possibly be fabricated by depositing a number of appropriate semiconductor layers within the manufacturing process of vertical nanowires. Simulation results indicate that a sustained inverse switching slope SS = 26 mV/dec can be achieved using GaAs/AlGaAs as the constituent materials of the superlattice, and that an on-current I(ON) = 0.5 mA/mu m can be obtained at V(GS) = V(DS) = 0.4 V by a careful optimization of the superlattice geometry. Further improvements are expected by an appropriate choice of the semiconductor pairs. (C) 2011 Elsevier Ltd. All rights reserved.