The University of Southampton
University of Southampton Institutional Repository

Origin of the OFF state variability in ReRAM cells

Origin of the OFF state variability in ReRAM cells
Origin of the OFF state variability in ReRAM cells
This work exploits the switching dynamics of nanoscale Resistive Random Access Memory (ReRAM) cells with particular emphasis on the origin of the observed variability when consecutively cycled/programmed at distinct memory states. It is demonstrated that this variance is a common feature of all ReRAM elements and is ascribed to the formation and rupture of conductive filaments that expand across the active core, independently of the material employed as the active switching core, the causal physical switching mechanism, the switching mode (bipolar/unipolar) or even the unit cells’ dimensions. Our hypothesis is supported through both experimental and theoretical studies on TiO2 and In2O3:SnO2 (ITO) based ReRAM cells while programmed at three distinct resistive states. Our prototypes employed TiO2 or ITO active cores over 5×5 µm2 and 100x100 µm2 cells’ areas, with all tested devices demonstrating both unipolar and bipolar switching modalities. In the case of TiO2-based cells, the underlying switching mechanism is based on the non-uniform displacement of ionic species that foster the formation of conductive filaments. On the other hand, the resistive switching observed in the ITO-based devices is considered to be due to a phase change mechanism. The selected experimental parameters allowed us to demonstrate that the observed programming variance is a common feature of all ReRAM devices, proving that its origin is dependent upon randomly oriented local disorders within the active core that have a substantial impact in the overall state variance particularly for high-resistive states.
0022-3727
1-10
Salaoru, I.
e3ef4b52-c1df-4ecc-ad0f-472836857407
Khiat, A.
bf549ddd-5356-4a7d-9c12-eb6c0d904050
Berdan, R.
082f1f5b-eaee-48a6-b728-414fc65f72bd
Quingjian, L.
801900bb-987f-499a-8ff4-3559f6d39930
Papavassiliou, C.
5faf408a-ca30-47e5-8283-4a65536f91ff
Prodromakis, T.
d58c9c10-9d25-4d22-b155-06c8437acfbf
Salaoru, I.
e3ef4b52-c1df-4ecc-ad0f-472836857407
Khiat, A.
bf549ddd-5356-4a7d-9c12-eb6c0d904050
Berdan, R.
082f1f5b-eaee-48a6-b728-414fc65f72bd
Quingjian, L.
801900bb-987f-499a-8ff4-3559f6d39930
Papavassiliou, C.
5faf408a-ca30-47e5-8283-4a65536f91ff
Prodromakis, T.
d58c9c10-9d25-4d22-b155-06c8437acfbf

Salaoru, I., Khiat, A., Berdan, R., Quingjian, L., Papavassiliou, C. and Prodromakis, T. (2014) Origin of the OFF state variability in ReRAM cells. Journal of Physics D: Applied Physics, 47 (14), 1-10. (doi:10.1088/0022-3727/47/14/145102).

Record type: Article

Abstract

This work exploits the switching dynamics of nanoscale Resistive Random Access Memory (ReRAM) cells with particular emphasis on the origin of the observed variability when consecutively cycled/programmed at distinct memory states. It is demonstrated that this variance is a common feature of all ReRAM elements and is ascribed to the formation and rupture of conductive filaments that expand across the active core, independently of the material employed as the active switching core, the causal physical switching mechanism, the switching mode (bipolar/unipolar) or even the unit cells’ dimensions. Our hypothesis is supported through both experimental and theoretical studies on TiO2 and In2O3:SnO2 (ITO) based ReRAM cells while programmed at three distinct resistive states. Our prototypes employed TiO2 or ITO active cores over 5×5 µm2 and 100x100 µm2 cells’ areas, with all tested devices demonstrating both unipolar and bipolar switching modalities. In the case of TiO2-based cells, the underlying switching mechanism is based on the non-uniform displacement of ionic species that foster the formation of conductive filaments. On the other hand, the resistive switching observed in the ITO-based devices is considered to be due to a phase change mechanism. The selected experimental parameters allowed us to demonstrate that the observed programming variance is a common feature of all ReRAM devices, proving that its origin is dependent upon randomly oriented local disorders within the active core that have a substantial impact in the overall state variance particularly for high-resistive states.

This record has no associated files available for download.

More information

Published date: 20 March 2014
Organisations: Nanoelectronics and Nanotechnology

Identifiers

Local EPrints ID: 362461
URI: http://eprints.soton.ac.uk/id/eprint/362461
ISSN: 0022-3727
PURE UUID: 2e58252a-0508-4ab2-986e-0f4908916d25
ORCID for T. Prodromakis: ORCID iD orcid.org/0000-0002-6267-6909

Catalogue record

Date deposited: 25 Feb 2014 10:27
Last modified: 14 Mar 2024 16:08

Export record

Altmetrics

Contributors

Author: I. Salaoru
Author: A. Khiat
Author: R. Berdan
Author: L. Quingjian
Author: C. Papavassiliou
Author: T. Prodromakis ORCID iD

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×