A Novel Extended Back-Gate Negative Capacitance TFET for Improved Device Performance

Abstract

We propose a novel Extended Back-Gate Overlap-Drain Negative Capacitance DGTFET (EBGODDG-NCTFET) with improved DC performances. Even though EBGODDG-NCTFET shows a great improvement in ON-state current (ION) and subthreshold swing (SS) owing to the introduction of the Ferroelectric (FE) layer, a detailed comparative analysis has been carried out to study the effect of the Extended Back-Gate Overlap-Drain on ambipolar conduction, OFF-state current and turn-on voltage of DG-NCTFET. The proposed EBGODDG-NCTFET in which only the back gate overlaps the drain has been found suppressing the ambipolarity up to a great extent. This structure of DG-NCTFET may resolve the trade-off between ambipolarity and parasitic capacitance by using back gate–drain overlap only. Due to a strong vertical electrical field causing greater depletion inside drain region, width of drain/channel tunneling barrier attains a larger value in EBGODDG-NCTFET, thus preventing charge carriers from tunneling during ambipolar state.