Forming-Free and Self-Limited Multilevel Switching in TaO2/MnO Memristor Crossbar Arrays for High-Performance Memory Applications

Memristors have emerged as one of the most promising candidates for next-generation nonvolatile memory and neuromorphic computing. However, several critical challenges continue to hinder their large-scale adoption. These include the necessity of a high-voltage electroforming process, the dependence on external current compliance circuitry during operation, and persistent issues such as device variability, limited endurance, and poor data retention in many material systems. We report forming-free and self-limited resistive switching in Ag/TaO2/MnO/Pt memristors fabricated as 10 × 10 crossbar arrays for high-performance nonvolatile memory applications. The fabricated devices eliminate the electroforming process, significantly simplifying fabrication and enhancing device reliability. Moreover, intrinsic self-compliance during switching removes the requirement for external current-limiting circuits, substantially reducing complexity and power consumption. The devices exhibit exceptional pulse endurance, sustaining over 106 switching cycles while consistently maintaining an ON/OFF ratio exceeding 105. Accelerated high-temperature retention tests, analyzed through Arrhenius extrapolation, project reliable data retention of over 10 years at 55 °C. Additionally, precise modulation of SET pulse amplitudes enables stable multilevel switching, demonstrating clear multibit memory capability. Comprehensive variability analyses confirm excellent cycle-to-cycle consistency (LRS variation ∼3%) and minimal device-to-device variability, crucial for scalable array integration. These results highlight the potential of TaO2/MnO-based memristor arrays to address major challenges of existing resistive memory technologies, positioning them as strong candidates for next-generation high-density memory and neuromorphic computing systems.