Direct Observation of Dual-Filament Switching Behaviors in Ta2O5-Based Memristors

Chia-Fu Chang, Jui-Yuan Chen, Chun-Wei Huang, Chung-Hua Chiu, Ting-Yi Lin, Ping-Hung Yeh, and Wen-Wei Wu, 2017
filament composed by a stack of oxygen vacancies and Ag metal
Image courtesy of Small


The Forming phenomenon is observed via in situ transmission electron microscopy in the Ag/Ta2O5/Pt system. The device is switched to a low-resistance state as the dual filament is connected to the electrodes. The results of energy dispersive spectrometer and electron energy loss spectroscopy analyses demonstrate that the filament is composed by a stack of oxygen vacancies and Ag metal.

Impact Statement

Ag/Ta2O5/Pt RRAM devices have low power consumption and high stability. By measuring electrical properties of FIB sample in atmosphere and vacuum, role of humidity and affects the Ag+ concentration was shown. EDS and EELS results indicated that the filament composed of the oxygen vacancies and Ag atoms forms the dual filament.