Bulk Oxygen–Ion Storage in Indium–Tin–Oxide Electrode for Improved Performance of HfO2-Based Resistive Random Access Memory

Abstract

Indium–tin–oxide (ITO) is investigated as the top electrode material in HfO2-based resistive random access memory cells. Experimental results show that in contrast to a metal (Pt) electrode, an ITO electrode provides for self-limiting current flow during the forming and SET processes, so that no compliance limit is necessary. This provides for low-power consumption, high endurance ( $> 10^{7}$ cycles), and short SET/RESET transition times ( $\sim 50$ ns). We propose that this is because ITO is an oxygen-vacancy-rich material, providing bulk storage for oxygen ions rather than surface storage as a metal electrode.