Possible Equivalent Circuit Model and Physical Structures of Sputter-Deposited Silicon Oxide Film Showing Resistive Switching

Based on the results of experiments on the resistive switching behaviors of sputter-deposited silicon oxide films, this paper proposes a possible equivalent circuit model to characterize the switching behavior at room temperature. It is revealed that frequency dispersion of the conductance component and capacitance component in the equivalent circuit model dominate the physical interpretation of the frequency-dependence of the components. The validity of the model and its physical interpretation are examined based on a theoretical model of the dielectric function of the conductive filament region. The polarizability of the conductive filament region suggests that the capacitance component of the conductive filament is insensitive to frequency in the low frequency range, whereas the conductance component of the conductive filament is proportional to frequency in the low frequency range. These theoretical results match experimental findings, and it is revealed that the equivalent circuit models and the frequency dispersion models for the capacitance and conductance component of the silicon oxide film are acceptable. In addition, this paper reveals the importance of the volume of the sub-oxide region and the Si precipitate region in determining the resistive switching behaviors of sputter-deposited silicon oxide film.