Realization of the Switching Mechanism in Resistance Random Access Memory (RRAMTM) Devices: Structural and Electronic Properties Affecting Electron Conductivity in Halfnium Oxide-Electrode System through First Principles Calculations

TL;DR

This paper uses first-principles calculations to elucidate the oxygen vacancy migration mechanism underlying resistive switching in HfO2-based RRAM devices, linking atomic-scale properties to device operation.

Contribution

It introduces a detailed atomic-level understanding of the switching mechanism in RRAM based on oxygen vacancy migration in HfO2, supported by DFT calculations.

Findings

Activation energy barriers match experimental voltages

Oxygen vacancy migration influences electronic properties

Mechanism aids materials design for RRAM

Abstract

Resistance Random Access Memory (RRAMTM) device, with its electrically induced nanoscale resistive switching capacity, has been gaining considerable attention as future non-volatile memory device. Here, we propose a mechanism of switching based on oxygen vacancy migration-driven change in electronic properties of the transition metal oxide (TMO) film stimulated by set pulse voltages. We used density functional theory (DFT)-based calculations to account for the effect of oxygen vacancy and its migration on the electronic properties of HfO2 and Ta/HfO2 systems, and thereby create the entire story on RRAMTM's switching mechanism. Computational results on the activation energy barrier for oxygen vacancy migration were found to be consistent with the results of set and reset pulse voltage obtained from experiment. Understanding of this mechanism would be beneficial to effectively realize materials design in these devices.