Effects of Back-Gate Bias on Subthreshold Swing of Tunnel Field-Effect Transistor

Jaehong Lee,Garam Kim,Sangwan Kim

doi:10.3390/electronics8121415

Jaehong Lee, Garam Kim + Show 1 more

Open Access

https://doi.org/10.3390/electronics8121415

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Abstract

In this study, the effects of back-gate bias on the subthreshold swing (S) of a tunnel field-effect transistor (TFET) were discussed. The electrostatic characteristics of the back-gated TFET were obtained using technology computer-aided design (TCAD) simulation and were explained using the concepts of turn-on and inversion voltages. As a result, S decreased, when the back-gate voltage increased; this behavior is attributed to the resultant increase in inversion voltage. In addition, it was found that the on–off current ratio of the TFET increased with a decrease in S due to the back-gate voltage.

Highlights

A continuous scaling of metal–oxide–semiconductor field-effect transistors (MOSFETs) has enabled integrated circuit (IC) chips to be fabricated with more functionality and at a lower cost [1,2]
FinFETs have a theoretical limit on subthreshold swing (S), since they are based on Boltzmann statistics as well
In this study, the subthreshold characteristics of a back-gated tunnel field-effect transistor (TFET) are extensively analyzed by means of technology computer-aided design (TCAD)

Summary

Introduction

A continuous scaling of metal–oxide–semiconductor field-effect transistors (MOSFETs) has enabled integrated circuit (IC) chips to be fabricated with more functionality and at a lower cost [1,2]. Multi-gated (MG) FETs (e.g., FinFETs) have replaced conventional FETs, which face a physical limit on scaling owing to short-channel effects [3]. Most TFETs use silicon-on-insulator (SOI) structures; it is very important to understand how a back-gate bias (V bg ) affects the operation of TFETs. A few studies have reported that back-gate biases change the transfer characteristics of TFETs [8,10]. In this study, the subthreshold characteristics of a back-gated TFET are extensively analyzed by means of technology computer-aided design (TCAD). The results obtained were used to analyze the influence of back-gate bias on the transfer characteristics of the TFET, especially the subthreshold swing.

Simulation Conditions

In order to rigorously examine the BTBT summarized

Results and Discussions

Transfer

Conclusions