Characteristics of gate-all-around hetero-gate-dielectric tunneling field-effect transistors

In this paper, gate-all-around (GAA) tunneling field-effect transistors (TFETs) with hetero-gate dielectric (HG) materials have been simulated and their characteristics have been optimized as a function of the high-k dielectric length (L _high-k). For the optimization of Lhigh-k, simulation results have been analyzed in terms of on- and off-current (I _on, I _off), subthreshold swing (SS), on/off current ratio, intrinsic delay time (τ), and RF performances. In the device simulations, the on-current characteristics were optimized when L _high-k is 8 nm. The optimized GAA HG TFET had ∼100 times higher Ion and ∼2 times improved SS than a GAA SiO ₂-only TFET. It has also been shown that the RF performances of TFETs can be improved by introducing an HG structure.