Investigation on the performance limits of Dirac-source FETs

In this work, we develop a two-dimensional (2D) simulation tool addressing Poisson’s equation within the semiconductor section of a 2D Dirac source (DS) field-effect transistor under the assumption of ballistic transport. Next, we compute the current curves using the WKB approximation for the calculation of the transmission probability. The current turns out to be quite sensitive to the tunneling probability at the graphene-semiconductor heterojunction. Different gate-insulating materials and gate lengths are considered with the aim of identifying any possible limitations in the performance of DS-FETs. The obtained results highlight some important issues, while confirming that a minimum subthreshold swing (SS) of 40 mV/dec can be achieved and that SS values below 60 mV/dec can be extended up to three and a half decades. • Accurate potential profiles are essential to estimate the current in DS-FETs. • Transmission in ballistic regime is analyzed to find its impact on the I-V behavior. • High- κ dielectrics, like HfO 2 , degrade the performance of DS-FETs. • DS-FETs can achieve an SS below 60 mV/dec even with channel lengths down to 4 nm.