Pt/ZrO_x/Al₂O₃/TiN self-rectifying memristor crossbar array based on synergistic effect of interface barrier modulation and oxygen vacancy migration

Sneak path current phenomenon in the cross-point memristor array may cause crosstalk, thus limiting its application in high-density large-scale arrays. Self-rectifying memristor is the best choice to suppress leakage current without adding additional device units, which effectively reduces the process cost. In this paper, a 2-layer 8 × 8 vertically stacked Pt/ZrO_x/Al₂O₃/TiN self-rectifying memristor array was fabricated. By adjusting the thickness of the Al₂O₃ layer, the rectification ratio of the self-rectifying memristor was improved to 5.18 × 10³, the nonlinearity could reach 1.63 × 10², and its sneak current was less than 1 nA. The self-rectification mechanism based on the synergistic effect of Schottky barrier modulation and oxygen vacancy migration was explored by fitting analysis and interface barrier band model. Under the premise of 10 % read margin of the device unit parameters, the maximum array size can reach 17471. It is further confirmed that the memristor unit can suppress the sneak current, which effectively promotes the development of high-density integrated arrays.