In general, resistive random access memory (R-RAM) denotes all of the random access memories that rely on the resistance differences to store data. Usually, a R-RAM storage device has a sandwich metal–insulator– metal (MIM) structure. By changing the insulator layer to a high-resistance state (HRS) or a low-resistance state (LRS), a R-RAM device can represent logic ‘0’ or ‘1,’ respectively. Various R-RAM materials based on different physical mechanisms have been extensively studied. For its high density, low power consumption, simple fabrication process, and good scalability, R-RAM has become a good candidate to substitute for traditional data storage technologies (e.g., hard disk drives and flash memory) [5, 7].