Experimental study of progressive breakdown in different conductance states of resistive switching structures

In this work, the breakdown transients of Al2O3- and HfO2-based metal-insulator-metal (MIM) stacks with the same oxide thickness and identical metal electrodes are studied. The differences and similarities between these transients in the progressive breakdown regime are assessed. Results show that Al2O3 exhibits longer breakdown transients than HfO2 and requires a higher voltage to initiate a very fast current runaway across the dielectric film. Similar results are observed when the devices are in remarkably different conductive states reached as a consequence of a resistive switching event. This suggests that both resistive switching and breakdown processes are linked to the thermal properties of the oxides under test rather than to dissipation effects occurring at the metal electrodes.