A study on mechanism of resistance distribution characteristics of oxide-based resistive memory

Although oxide-based resistive switching memory (OxRAM) is one of the strong next-generation high capacity memory candidates, it has the critical disadvantage that deviations of resistance levels is too severe to be adopted as a high capacity memory device. More specifically, it is known that the larger on/off current ratios in multi-level operated OxRAMs, the greater deviation of resistance levels from the targeted values. However, despite the seriousness of the problem there has been no concrete theoretical study on the underlying mechanisms of the phenomenon. In this paper, we introduce a theoretical model that clearly explain the underlying mechanism of making such characteristics of programmed resistance levels in multi-level OxRAMs. From this model, we can understand why there is a proportional relationship between resistance level and its deviation, and why it has such a specific range of proportionality constant measured experimentally. And this understanding can certainly reveal the true limitations of OxRAMs’s performance.