Improving Performance by Inserting an Indium Oxide Layer as an Oxygen Ion Storage Layer in HfO₂-Based Resistive Random Access Memory

Abstract

This study investigates an improvement in memory characteristics through depositing an In2O3 layer as an oxygen ion reservoir in the switching layer (SL) of resistive random access memory (RRAM). The deposition of In2O3, denoted as Pt/HfO2/In2O3/TiN device, provides better memory characteristics including lower forming voltage ( ${V}_{F}$ ), set/reset voltage ( ${V}_{\mathrm {SET}}/{V}_{\mathrm {RESET}}$ ), larger memory window, and higher resistances with higher uniformity at low resistance state (LRS) and high resistance state (HRS), compared to the devices without the In2O3 deposition, denoted as Pt/HfO2/TiN device. The conduction mechanisms, verified through fitting current–voltage ( ${I} - {V}$ ) curves, are consistent with the results of a varied temperature ${I} - {V}$ experiment. Finally, a physical model is proposed to explain our observations.