Deposition of Bi2O3 Thin Films and Their Resistive Switching Characteristics

Resistive random access memory (ReRAM) is one of the most promising candidates for next generation high speed nonvolatile memory devices. Bi2O3 thin films were deposited on heavily doped silicon wafer by RF magnetron sputtering, and the crystalline structure of the Bi2O3 thin films were characterized by XRD. The resistive switching characteristics of the Au/Bi2O3/n(+)Si/Al structure and the dependence of the ReRAM behavior on the thickness of the Bi2O3 thin films were studied. XRD analysis shows that the Bi2O3 thin films have good crystalline quality with (201) preferential orientation, while I-V curves results indicate that Bi2O3 thin films exhibit reversible and steady unipolar resistive switching behaviors. It is further found that the forming voltages, set voltages, and reset voltages depend linearly on the thickness of Bi2O3 thin films, and for the device with the thickness of 31.2 nm, these three threshold voltages are all below 4 V, which meet the need of low voltage operation of the memories.