Electroforming-Free, Self-Rectifying Selector-Only Memory With Diffusive Cu-Ion Dynamics for Logic-In-Memory...

A selector-only memory (SOM), performing the dual functions of a selector and memory in a single device, has emerged as a promising candidate to overcome critical issues such as high aspect ratio and thermal disturbance in 3D X-point arrays (3DXP) for compute-express-link (CXL). Nevertheless, previously reported SOMs based on ovonic threshold switching (OTS) still have limitations in adoption as a new memory solution for 3DXP, owing to the requirement of an electroforming process at high voltage, bidirectional high current flow, and the intrinsic drift phenomenon. Here, we report a novel electroforming-free self-rectifying SOM (SR-SOM) that exhibits a diode-like unidirectional current flow and high endurance of ∼10⁸ cycles. Previous SOM strategies have relied primarily on chalcogenide-based OTS selectors to induce threshold voltage modulation. By contrast, our SR-SOM operates via diffusive Cu-ion dynamics, where the polarity-induced threshold-voltage shift originates from atomic migration under an applied bias, and the ultrafast self-rupturing of conductive Cu filaments enables drift-free properties with sub-20-ns. Moreover, by implementing a logic-in-memory scheme, we demonstrated all 16 Boolean logic functions and a full adder operation, verifying the multifunctional capability of SR-SOM for both memory and logic operations.