Assessing the spatial correlation and conduction state of breakdown spot patterns in Pt/HfO2/Pt structures using transient infrared thermography

The generation and conduction state of breakdown spot patterns in HfO2-based metal-insulator-metal structures are investigated using transient infrared thermography in combination with spatial statistics. The spots are created at a low generation rate by applying an appropriate constant voltage stress to the devices. Because of the important thermal effects involved during degradation, the breakdown events leave their fingerprints on the top metal electrode in the form of two-dimensional point patterns. Contrary to what is expected, thermal mappings reveal that many of these failure sites do not longer conduct after their creation, which is consistent with a self-healing behavior. In order to investigate whether the local heat dissipation and thermal propagation induce spatial correlation among the failure events or not, the final breakdown spot spatial distributions are compared with simulations of homogeneous Poisson point processes in the plane and the results are validated against the smoothed residual field and quantile-quantile plots.