Wake-Up Effects on Improving Gradual Switching and Variation in Al₂O₃-Based RRAM

Resistive random-access memory (RRAM) has been attractive as an emerging memory that can be used for computing-in-memory (CIM) and storage-class memory (SCM). However, achieving gradual resistive switching (RS) characteristics and minimizing the variability remain critical challenges. In this work, we investigate the wake-up effect in Al₂O₃-based RRAM and its role in improving RS properties. Two types of wake-up effects were found: HRS variation improvement and gradual switching during set operation. First, a reduction in current variation in the high-resistance state (HRS), which indicates improvement of filament stability and uniformity. Second, gradual switching during the set voltage sweep, suggesting a more gradual modulation of the conduction mechanism, likely related to interface conductive filament (CF) generation. By harnessing the wake-up effect, it is possible to overcome the limitations of RRAM, which allows writing only during the reset voltage sweep, to enable writing during the set voltage sweep as well.