Subthreshold swing characteristics of nanowire tunneling FETs with variation in gate coverage and channel diameter

•We demonstrate the simulated subthreshold swing (SS) of silicon nanowire TFETs.•The SS values are affected by changing channel thickness and gate coverage ratio.•For the TFETs, channel thickness is a major factor that determines the SS value.

In this study, we demonstrate the simulated subthreshold swing (SS) of silicon nanowire tunneling field-effect transistors (NWTFETs) by varying both the channel diameter from 10 nm to 40 nm and the gate coverage ratio from 30% to 100%. Our simulation work reveals that both a decrease in the channel diameter and an increase in the gate coverage ratio contribute to a reduction in the SS. Additionally, our work shows that the magnitude of the on-current depends linearly on the gate coverage ratio and that the drain current increases with a decrease in the channel diameter. Thus, an NWTFET with a channel diameter of 10 nm and a gate coverage ratio of 100% exhibits superior electrical characteristics over other silicon NWTFETs in that the NWTFET shows a point SS of 22.7 mV/dec, an average SS of 56.3 mV/dec, an on/off current ratio of ∼1013, and an on-current of ∼10−5 A/μm.