Analytical modeling and TCAD simulation for subthreshold characteristics of asymmetric Tunnel FET

Abstract

In this paper, a 2-D analytical model has been developed for asymmetric Tunnel FET known as Non-Uniform Body with Dual Material Source TFET (NUTFET-DMS) Device. The proposed model formulation is based on the solution of Poisson’s equation using suitable boundary conditions. The derived model for subthreshold characteristics is proposed for numerous device parameters such as surface potential, lateral, vertical electric fields, drain current and threshold voltage. In this work, for the first time the model accounts the prodigious non-uniform nature of the Channel, Gate Dielectric Thickness, Dielectric Constants and Oxide Capacitance, at different portions of the device. Next, to validate the accuracy of the model, device simulation using Sentaurus TCAD with calibrated models is reported and a close agreement with 85–95% accuracy is observed. The detailed and systematic device analysis is presented by studying different cases of applied biases, variation of device dimensions, oxide materials etc. It is reported that the proposed TFET device is able to obtain a vertical and lateral electric field of ± 5 MV/cm near the tunneling junction, implying a drain current in the order of 10−5A/μm. The present study highlights that the proposed TFET offers great potential for low standby power logic and low power applications.