Simultaneous observation of the surface topography and current flow of PZT thin films using an atomic force microscope

Simultaneous observations of the surface topography and current flow of Pb(Zr,Ti)O-3 (PZT) thin films were performed for the first time by using an atomic force microscope (AFM) with a conductive cantilever. In a leaky PZT thin film with a rough surface, many local spots where the current easily flowed were observed. By comparing the current images with the topographic images, it was found that current flow through the PZT thin film was primarily localized at the grain boundaries. We believe that the conduction through grain boundaries is the dominant current conduction pathway. On the other hand, in a less leaky PZT thin film with a smooth surface, the current flowed only minimally over the entire surface. Therefore, we think that the current flows through both the bulk grains and the grain boundaries.