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 (Lhigh-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 (tau), and RF performances. In the device simulations, the on-current characteristics were optimized when Lhigh-k is 8 nm. The optimized GAA HG TFET had similar to 100 times higher I-on and similar to 2 times improved SS than a GAA SiO2-only TFET. It has also been shown that the RF performances of TFETs can be improved by introducing an HG structure. (C) 2012 The Japan Society of Applied Physics