Cell-to-Cell Fundamental Variability Limits Investigation in OxRRAM Arrays

In this letter, the fundamental variability limits of filament-based OxRRAM are investigated considering different transistor sizes and metal-insulator-metal (MIM) stacks featuring different materials and thicknesses. Cell-to-cell variability is analyzed through an extensive characterization of Forming, Set, and Reset operations on 4-kb OxRRAM arrays. The results obtained in terms of switching voltage variability and resistance variability from cell-to-cell are compared and discussed to identify the variability limiting component as a function of the conduction regime and to understand the impact of transistor MIM stack parameters on variability and performances.