Study on High-Resistance State Instability of TaOx-Based RRAM

High-resistance state instability (HRSI) is one of the major challenges that obstruct the application of resistive random access memory (RRAM) in commercial markets. In this letter, we studied the mechanism of HRSI of TaOx-based RRAM with a statistical methodology. During DC sweep, the model is able to calculate the defect numbers when the endurance degradation and short-term HRSI occur. Our result reveals that these two kinds of HRSI both have a strong connection with the change of defect numbers which play an important role in current conduction. According to our analysis, the endurance degradation is caused by the increase in fixed defect numbers, while short-term HRSI originates from the relaxation induced by reduction of defect numbers.