Simulation of planar single-gate Si tunnel FET with average subthreshold swing of less than 60 mV/decade for 0.3 V operation

Planar single-gate (SG) silicon (Si) tunnel field effect transistors (TFETs) are attracting interest for ultra-low voltage operation and CMOS applications. For the achievement of subthreshold swing (S.S.) less than thermal limit of Si MOSFETs (S.S. = 60 mV/decade at 300 K), previous studies have proposed the formation of a pocket region, which needs very difficult implantation process. In this work, a planar SG Si TFET without pocket was proposed by using the technology computer-aided design (TCAD) simulations. An average S.S. of less than 60 mV/decade for 0.3 V (= Vgs = Vds) operation was obtained. It is found that both low average S.S. (= 27.8 mV/decade) and high on-current Ion (= 3.8 µA/µm) are achieved without pocket doping by scaling the equivalent oxide thickness (EOT) and increasing the gate-to-source overlap length Lov.