Study on the Resistive Switching Mechanism of Cr/HfO ₂ /Cu Devices Based on First‐Principle

Driven by surging storage demand in big data and AI, conductive‐bridging random access memory (CBRAM), with high on/off ratio and low operating voltage, is a key next‐generation nonvolatile memory candidate. However, controversies over the resistive switching mechanism in HfO ₂ ‐based CBRAM hinder performance and reliability optimization. This study combines experiments and first‐principles calculations to systematically investigate the resistive switching behavior and microscopic mechanism of Cr/HfO ₂ /Cu CBRAM devices. At room temperature, the device exhibits a forming voltage below 2.09 V, a high/low resistance ratio of 10 ³ , and stable retention over 3 × 10 ³ s. I – V curve fitting confirms Ohmic conduction in the low‐resistance state (LRS) and space‐charge‐limited conduction (SCLC) in the high‐resistance state (HRS), verifying the resistive switching core as the formation and rupture of Cu conductive filaments. Theoretical analysis reveals that interstitial Cu (Cu _i ) has a low formation energy of −10.30 eV, facilitating filament formation, while oxygen vacancies (V _O ) increase the Cu ion migration barrier, exacerbating parameter fluctuations. Charge density difference analysis clarifies the charge transfer behavior between Cu and HfO ₂ and identifies the Cu migration pathways. These findings provide a theoretical basis for optimizing CBRAM device performance and reliability.