Enhanced resistive switching characteristics of conductive bridging memory device by a Co-Cu alloy electrode

One of the main challenges in the development of conductive bridging random access memory (CBRAM) is the large stochastic nature of ion movement that ultimately leads to large parameter variability. In this study, the resistive switching variability of CBRAM devices is significantly improved by employing Co-Cu alloy as the active electrode. By comparing with Pt/Ta2O5/Co devices, the Co70Cu30 alloy exhibited lower forming voltage (<2 V), lower SET voltage (<0.70 V), and faster response time (70 ns). The filament stability indicated by the distribution of SET/RESET voltage and high resistance state/low resistance state variation was significantly improved. Our experimental results suggest the formation of Co filaments, and the proposed mechanism is governed by the galvanic effect. In addition, a comparison between Co70Cu30 and Co30Cu70 alloys highlights that the relative proportion between Co and Cu plays an essential role in the device performance. A physical model based on different electrochemical activities of the alloys has been proposed to explain the filament formation and the improved switching uniformity in the Co70Cu30 alloy. This study not only develops a CBRAM with enhanced performance but also advances the implementation of suitable alloy systems for the application of such devices.

Automated summary

The resistive switching variability of CBRAM devices is significantly improved by employing Co-Cu alloy as the active electrode, resulting in improved filament stability and device performance. Through experimental results and a physical model, the advantages of Co70Cu30 alloy in CBRAM have been demonstrated, highlighting the significant influence of the relative proportion between Co and Cu on the device performance.