Investigating the electro-thermal origin of breakdown in low-K/Cu dielectrics under short duration over stressed pulsed regime

We present a detailed study of low-K/Cu structures under short duration pulse regime and establish a microscopic understanding of breakdown behavior under high current stressing. Random and anomalous behavior of the breakdown characteristics observed under very fast pulsing conditions are explained through electro-thermal instability. A model based on extensive experimental study has been developed to show switching behavior of a conducting path (short failure) due to meltdown of copper. The dumping of critical energy can lead to permanent damage and leads to an open failure. Established breakdown model has been critically linked to the material behavior and extrapolated to understand the TDDB behavior of the low K dielectric.