Giant Electroresistance in Edge Metal-Insulator-Metal Tunnel Junctions Induced by Ferroelectric Fringe Fields

Sungchul Jung,Kibog Park,Jung-Yong Lee,Youngeun Jeon,Nam Kim,Jae-Hyeon Ko,Daejin Eom,Hanbyul Jin

doi:10.1038/srep30646

Abstract

An enormous amount of research activities has been devoted to developing new types of non-volatile memory devices as the potential replacements of current flash memory devices. Theoretical device modeling was performed to demonstrate that a huge change of tunnel resistance in an Edge Metal-Insulator-Metal (EMIM) junction of metal crossbar structure can be induced by the modulation of electric fringe field, associated with the polarization reversal of an underlying ferroelectric layer. It is demonstrated that single three-terminal EMIM/Ferroelectric structure could form an active memory cell without any additional selection devices. This new structure can open up a way of fabricating all-thin-film-based, high-density, high-speed, and low-power non-volatile memory devices that are stackable to realize 3D memory architecture.

Highlights

The electron energy band profiles across the tunnel barrier for the two different polarization directions in the underlying ferroelectric layer are depicted in Fig. 2a,b respectively
In case of polarization up-state, positive polarization charges are induced on the surface of the ferroelectric layer and these positive polarization charges lead to the valley-shaped energy band profile in the tunnel insulator
We demonstrated with theoretical device modeling that the tunnel current in an Edge MetalInsulator-Metal (EMIM) junction of metal crossbar structure can vary drastically depending on the polarization direction of an underlying ferroelectric layer

Summary

Introduction

The electron energy band profiles across the tunnel barrier for the two different polarization directions in the underlying ferroelectric layer are depicted in Fig. 2a,b respectively. For polarization down-state, negative polarization charges are induced on the surface of the ferroelectric layer, which arouse the ridge-shaped energy band profile in the tunnel insulator.

Results

Conclusion