Polymer-Assisted Solution Processing of TiO2 Thin Films for Resistive-Switching Random Access Memory

Abstract

In this study, we present a polymer-assisted solution (PAS) process to prepare TiO2 electrolyte layers for resistive-switching random access memory (ReRAM). The PAS process utilizes the stability of metal-polymer complexes in the coating solution to form uniform and dense films. In addition, the viscosity of the PAS coating solution can easily be adapted for any currently used coating technique. The electrochemical-metallization-based (ECM-based) ReRAM devices were prepared by spin-coating the PAS coating solution on an indium tin oxide (ITO) glass substrate that is used as the bottom electrode. Cu was deposited on the PAS-TiO2 electrolyte as an electrochemically active metal electrode used as the top electrode. The ECM-based ReRAM with the PAS-TiO2 electrolyte layer demonstrated bipolar resistive-switching behavior with a memory window wider than 13, cycle endurance over 500 cycles, and retention time longer than 104 s. Analysis of the conduction mechanism in high and low resistive states indicates that the resistive switching is attributed to the formation and rupture of Cu conducting filaments (CFs) in the PAS-TiO2 electrolyte layer.