Ambipolar Performance Improvement of Dual Material TFET Using Drain Underlap Engineering

Abstract

A dual-material gate tunnel-field effect transistor along with drain underlap engineering (UDM-TFET)is proposed to enhance the on-current (I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ON</inf> )and minimize the ambipolar current simultaneously. The device reduces ambipolar current <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\mathrm{I}_{\mathrm{a}\mathrm{m}\mathrm{b}})$</tex> significantly by decreasing the length of the auxiliary gate. Moreover, the dual work function of the metal gate exhibits enhanced order of ION by reducing the tunneling length at the source/channel interface, thus improves the ratio of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{I}_{\mathrm{O}\mathrm{N}}/\mathrm{I}_{\mathrm{a}\mathrm{m}\mathrm{b}}$</tex> . The proposed device structure has been simulated using Synopsys TCAD device simulator and the results are compared with that of conventional TFET, dual-material gate TFET (DMG-TFE T). The proposed structure with low ambipolar conduction and higher drain current can be considered in low power application.