Integration aspects for damascene copper interconnect in low k dielectric

Statistical and physical analysis of leakage and breakdown failure mechanisms of Cu/low-k interconnects

“…This type of failures could originate from Cu CMP process. For example, local regions where scratch defects or under-polished Cu are incurred leaving behind Cu residues in between metal lines [9] will result in a high leakage current and eventually an electrical short failure.…”

Dielectric failure mechanisms in advanced Cu/low-k interconnect architecture

“…Cu residues can be found outside the diffusion barrier due to re-sputtered Cu onto the via sidewalls induced during via etching [76]. Cu residues can also be found on the low-k dielectric surface due to micro-scratches, arc-scratches or incomplete CMP polishes [77,78]. An increase in Cu particles at the CMP surface was also found after prolonged exposure to the ambient before cap barrier deposition [79,80].…”