2, Murata Manufacturing Co., Ltd., Yasu, Shiga, Japan
Dielectric thin films are crucial for countless computing, wireless, and sensor systems. As their dimensions continue to diminish, and engineered microstructure becomes increasingly refined, it is crucial to be able to investigate charging, discharging, and breakdown at the nanoscale. Based on Atomic Force Microscopy several new approaches have been developed for such investigations, reported here for BaTiO3 as well as BaTiO3 and SrTiO3 superlattices. In this manner, the influence on charging and discharging can be mapped for grain boundaries as well as heterostructure interfaces. Furthermore, by applying voltages up to 150V, in a controlled environment, across films shallow-angle-polished to create thicknesses gradients from 200 down to 2 nm, scaling laws for breakdown become uniquely accessible on a single specimen. This is advantageous as the composition is reasonably consistent, as compared to investigations with multiple films. Such methods are equally applicable for investigations of breakdown mechanisms with inorganic as well as polymeric dielectrics.