Dual-material double-gate tunnel FET: gate threshold voltage modeling and extraction

A new analytical model for the gate threshold voltage ( V TG ) of a dual-material double-gate (DMDG) tunnel field-effect transistor (TFET) is reported. The model is derived by solving the quasi-two-dimensional Poisson’s equation in the lightly doped Si film and employing the physical definition of V TG . A numerical simulation study of the transfer characteristics and V TG of a DMDG TFET has been carried out to verify the proposed analytical model. In the numerical calculations, extraction of V TG is performed based on the transconductance change method as already used for conventional metal–oxide–semiconductor FETs (MOSFETs). The effects of gate length scaling, Si film thickness scaling, and modification of the gate dielectric on V TG are reported. The dependence of V TG on the applied drain bias is investigated using the proposed model. The proposed model can predict the effect of variation of all these parameters with reasonable accuracy.