On the contribution of line-edge roughness to intralevel TDDB lifetime in low-k dielectrics

A TDDB reliability experiment was performed on interdigitated comb structures with intentionally severe line-edge roughness and the results were then compared to a simple theoretical model. It is seen that for the case studied, the predictions of the model do not compare well to the experimental data, but that for some observed cases the effect of reducing spacing between lines is so strong that more substantial defects must be invoked as a source of failure.