Impact of Frequency From a Bipolar Applied Field on Dielectric Breakdown for Low- $k$ Materials

Assessing the lifetime of low-k dielectric materials integrated with Cu remains an important issue for interconnect reliability as designs pursue dielectric thicknesses below 100 nm. We present electrical tests and a mass transport model to assess Cu-catalyzed dielectric failure when transient fields are applied. We show that beyond a certain frequency of oscillation, dielectric lifetime can be enhanced up to two orders of magnitude. The proposed transport model predicts the dynamics observed experimentally and reproduces trends observed as we change field frequency and amplitude.