Structural Analysis and Performance in a Dual‐Mechanism Conductive Filament Memristor

Abstract

AbstractThe development of a dual‐filament model is vital for achieving better performance in next‐generation resistive random‐access memory (RRAM). In this work, the microstructure evolution and corresponding performance of a Cu/Ta2O5−x/Pt system are investigated at the atomic scale. By inducing intrinsic oxygen vacancies into tantalum oxide and applying copper as the active electrode, the RRAM device can exhibit the electrical properties of a dual‐mechanism filament. The device demonstrates a long retention time (104 s) and a large memory window of 106. By using high‐resolution transmission electron microscopy and high‐resolution X‐ray photoelectron spectroscopy, the conductive filament is found to consist of crystalline copper and oxygen vacancies. Moreover, with the growth kinetics of filaments from in situ transmission electron microscopy and curve fitting relevant to the conduction mechanism, the formation of filaments is promoted by field‐coalesced oxygen vacancies induced by the growth of copper filaments. Therefore, this work provides a unique perspective and a novel material engineering approach for tailoring RRAM devices and developing further applications in electronic technology.