Design and investigation of the double gate TFET with heterogeneous gate dielectric using different gate materials

Abstract

A 2 dimensional model of double gate hetero dielectric Tunnel Field Effect Transistor (HD-DG TFET) with hetero dielectric gate stack is carved with Silicon dioxide (SiO2) and Hafnium dioxide (HfO2) as dielectric materials. The electrical characteristics are demonstrated for the device by using 2D numerical device simulator Silvaco TCAD. The channel length, doping concentration of drain and source, thickness of device and effective oxide layer thickness of the device is kept constant throughout the work. It is showed that the proposed structure has better performance than Double Gate TFET. Also gate materials used are silver, gold, platinum and Npolysilicon. By using these materials Drain current and electric field of the device has been plotted. Also the proposed model shows a lower leakage current, better ION/IOFF ratio sub-threshold swing and lower DIBL. It has also been remarked that use of metal gate with appropriate work function along with high-k and hetero dielectric improves the carrier transport in the channel. This model aims to lower the short channel effects and give emphasis to improvement of switching ratio.