Oxygen Ion Drift-Induced Complementary Resistive Switching in Homo TiOx/TiOy/TiOx and Hetero TiOx/TiON/TiOx Triple Multilayer Frameworks

• Published in: Advanced functional materials 2012-02, Vol.22 (4), p.709-716
• Main Authors: Bae, Yoon Cheol, Lee, Ah Rahm, Lee, Ja Bin, Koo, Ja Hyun, Kwon, Kyung Cheol, Park, Jea Gun, Im, Hyun Sik, Hong, Jin Pyo
• Format: Article
• Language: English
• Subjects: memory devices; oxygen ion movement; resistive switching
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201102362

Developing a means by which to compete with commonly used Si‐based memory devices represents an important challenge for the realization of future three‐dimensionally stacked crossbar‐array memory devices with multifunctionality. Therefore, oxide‐based resistance switching memory (ReRAM), with its associated phenomena of oxygen ion drifts under a bias, is becoming increasingly important for use in nanoscalable crossbar arrays with an ideal memory cell size due to its simple metal–insulator–metal structure and low switching current of 10–100 μA. However, in a crossbar array geometry, one single memory element defined by the cross‐point of word and bit lines is highly susceptible to unintended leakage current due to parasitic paths around neighboring cells when no selective devices such as diodes or transistors are used. Therefore, the effective complementary resistive switching (CRS) features in all Ti‐oxide‐based triple layered homo Pt/TiOx/TiOy/TiOx/Pt and hetero Pt/TiOx/TiON/TiOx/Pt geometries as alternative resistive switching matrices are reported. The possible resistive switching nature of the novel triple matrices is also discussed together with their electrical and structural properties. The ability to eliminate both an external resistor for efficient CRS operation and a metallic Pt middle electrode for further cost‐effective scalability will accelerate progress toward the realization of cross‐bar ReRAM in this framework. A novel binary oxide‐based triple‐layer framework for complementary resistive switching is developed with anti‐serially merged two bilayer homojunction switching elements. The oxidation/redox reaction induced by movable oxygen ions at the interface between the middle TiOy and the top/bottom TiOx layers plays a key role in the resistive switching, together with the formation of filamentary paths under bias.