Observing the resistive switching of MgZnO thin film via conducting atomic force microscopy.

Conducting atomic force microscopy (C-AFM) is used to observe the formation and removal of conducting filaments of Mg0.6Zn0.4O thin film at a nanoscale in order to study the mechanisms of resistive switching. C-AFM probe with Pt coating is used as a movable top electrode for measuring local I-V and for C-AFM imaging. Writing and reading of micro-bits on the resistive switching thin film are demonstrated. The local I-V behavior is similar to the macroscopic behavior of the resistive switching thin film. However, the probability for successful in situ detection of resistive switching of formation in the current experiment is only one quarter, much less than that with a macroscopic top electrode. Experimental results are explained using the filament model which illustrates the switching mechanism of the thin film. The current work would be useful for the improvement of resistive switching thin films and their applications.