Highly-stable, Solution-processed Quaternary Oxide Thin Film-based Resistive Switching Random Access Memory

Abstract

Optimization and performance enhancement of low-cost and solution-processed InGaZnO (IGZO) resistance random access memory (ReRAM) device was demonstrated on the basis of manipulation of global and local oxygen vacancy (Vo) stoichiometry in metal oxide thin films. Controlled overall Ga composition within IGZO thin film reduced the excessive formation of oxygen vacancy for reproducible resistance switching mechanism. Furthermore, local sophisticated control of stoichiometric Vo using 5 nm Ni layer at the interface of IGZO layer consequently serves as an oxygen capturing layer by forming NiOx, consequently facilitating the formation of conductive filaments and also preventing the abrupt degradation of device performance. Additionally, reducing the cell dimension of IGZO-based ReRAMs using a cross-bar electrode structure appeared to drastically improve their performances such as the operation voltage and resistance distribution due to suppression of excessive conductive filament formation. Optimized ReRAM devices exhibit a stable unipolar resistive switching behavior with an endurance >200 cycles, retention time for 104 sec at 85 °C and on/off ratio higher than about 102. Therefore, it can be claimed that our findings address the demanding issues of low-cost memory devices with high stability and endurance for next-generation data storage technology.