Spatial Redistribution of Oxygen Ions in Oxide Resistance Switching Device after Forming Process

The change in the spatial distribution of oxygen ions after an initial voltage application called the forming process was investigated for oxide resistance switching devices by secondary ion mass spectrometry mapping. To track the motion of oxygen ions, tracer 18O ions were implanted in a planar Pt/CuO/Pt device. We found clear evidence for the oxygen reduction in the conductive bridge structure formed between two electrodes. In addition, the oxygen ions in the bridge structure drift to the anode, implying the oxygen diffusion (migration) induced by high electric field and/or current density. We discuss those results in terms of a filament model.