SiGe vertical NW GAA TFET with improved current and low leakage

A comparative study of the double gate MOSFET (DG MOSFET), vertical silicon gate all around nanowire (GAA-NW) tunneling field effect transistor (TFET) and SiGe-source HfO2-insulator GAA-NW TFET is presented to prove that the last can outperform the others in terms of high performance, energy efficiency, ultra-low power, high on-chip density and gate controllability. Scaling of transistors beyond FinFET is generally possible with the help of TFET while reducing the subthreshold swing (SS), short channel effects (SCE) and drain induced barrier leakage (DIBL). But the ambipolarity in Si TFET causes high Ioff current. Hence, here, a vertical Si-source SiO2-insulator GAA-NW TFET is studied to provide high Ion current, subthreshold swing less than 30 mV/decade and DIBL less than 20 mV/V, so that the channel length can be made independent of the footprint. These properties are further enhanced by the use of SiGe source and HfO2 insulator.