Bias Spectroscopy of Negative Differential Resistance in Ge Nanowire Cascode Circuits

In this paper, we exploit the nanometer scale properties of Ge based Schottky barrier field-effect transistors (SBFETs) with monocrystalline Al contacts, fusing the concept of reconfiguration and negative differential resistance (NDR) in a single device. Temperature dependent bias spectroscopy is used to investigate the electronic transport in the NDR regime leading to profound understanding of the involved physical transport mechanisms. Importantly, the obtained SBFETs are capable of shifting the NDR-peak by electrostatic gating. Thus, a cascode of such devices results in overlapping NDR regions, which allows the realization of new circuit topologies beyond the capabilities of conventional CMOS.