A Compact 2-D Analytical Model for Electrical Characteristics of Double-Gate Tunnel Field-Effect Transistors with a SiO2/High-k Stacked Gate-Oxide Structure

Abstract

A compact 2-D analytical model for electrical characteristics such as surface potential, drain current, and threshold voltage of double-gate tunnel FET (DG TFETs) with a SiO2/High- k stacked gate-oxide structure is proposed in this paper. Poisson's equation has been solved using parabolic approximation method to model the channel potential. The band-to-band tunneling generation rate has been expressed as a function of channel electric field derived from the channel potential and then integrated analytically over the channel thickness to derive the drain current of the stacked-gate DG TFETs using the shortest tunneling path (Lt min) concept. The effect of source/drain depletion regions has been included for the better accuracy of the proposed model. The maximum transconductance method has finally been used to extract the threshold voltage from the drain current of the device. The effects of various device parameters on the channel potential, drain current, and threshold voltage have been investigated. The model results have been compared with the simulation data obtained using the commercially available ATLAS 2-D device simulator from SILVACO for the validity of the proposed model. © 1963-2012 IEEE.