Switching and Failure Mechanism of Self-Selective Cell in 3D VRRAM by RTN-Based Defect Tracking Technique

Non-filament self-selective RRAM is a promising technology for 3D VRRAM application. However, direct experimental evidence for its switching and failure mechanism is still missing. In this work, we proposed the resistive switching and failure model of TaOX/HfO2 bilayer device in 3D vertical RRAM by RTN-based defect tracking technique. After extracting the locations and energy levels (XT, ET) of defects in both HRS and LRS, Defect-less Region in TaOX layer was directly observed which corresponded to the resistive switching. Furthermore, by monitoring the Defect-less Region in different cycling number and retention time, the main reason of the ON/OFF ratio degradation was revealed. This provides a useful tool for improving the non-filament RRAM technology.