Effects of Annealing Temperatures on Resistive Switching Characteristics of TiO2 Based ReRAM

TiO2 thin films were deposited on heavily doped silicon wafer by DC magnetron sputtering and the Au electrodes were evaporated on TiO2/n+-Si by electric beam evaporation to get Au/TiO2/n+-Si structured resistive random access memory (ReRAM). The effects of annealing temperatures on the crystalline structure of the TiO2 thin films and the resistive switching characteristics of the fabricated device were investigated. Au/TiO2/n+-Si structured device exhibits reversible and steady unipolar resistive switching behaviors. The values of set voltage, reset voltage, reset current and reset power vary with the annealing temperatures. The resistive switching mechanism is discussed based on the filamentary model. The results reveal that the fabricated device annealed at 500 as good nonvolatile property. The average ratio of resistances between high resistance state (HRS) and low resistance state (LRS) is larger than 103 and the devices could maintain a sufficient margin of memory for more than 10 years. The resistive switching characteristic is remained after 100 switching cycling tests.