am7b02921_si_001.pdf (140.92 kB)
Interfacial Metal–Oxide Interactions in Resistive Switching Memories
journal contribution
posted on 2017-05-16, 00:00 authored by Deok-Yong Cho, Michael Luebben, Stefan Wiefels, Kug-Seung Lee, Ilia ValovMetal
oxides are commonly used as electrolytes for redox-based resistive
switching memories. In most cases, non-noble metals are directly deposited
as ohmic electrodes. We demonstrate that irrespective of bulk thermodynamics
predictions an intermediate oxide film a few nanometers in thickness
is always formed at the metal/insulator interface, and this layer
significantly contributes to the development of reliable switching
characteristics. We have tested metal electrodes and metal oxides
mostly used for memristive devices, that is, Ta, Hf, and Ti and Ta2O5, HfO2, and SiO2. Intermediate
oxide layers are always formed at the interfaces, whereas only the
rate of the electrode oxidation depends on the oxygen affinity of
the metal and the chemical stability of the oxide matrix. Device failure
is associated with complete transition of short-range order to a more
disordered main matrix structure.