In this study, the bipolar resistive switching characteristics of the resistive random access memory (RRAM) device based on sputter-deposited TaON thin film were investigated. The proposed memory device exhibits excellent resistance switching behavior with a high resistance state to low resistance state ratio of 2.5 order, write/erase endurance of about 1.5 order, and long retention time of 10(4) s at 85 degrees C. In addition, the device was investigated to achieve multilevel operation, which could increase storage density for next generation memory application. It was also found that the polarity of the forming process would not influence the resistive switching characteristic but would affect the first reset process behavior. The switching behavior could be regarded as the oxygen redox near the TiN interface. However, the first reset behavior of negative forming process was related to the oxygen concentration gradients near the Pt electrode and the Joule heating enhanced oxidation. (c) 2012 Elsevier B.V. All rights reserved.