CMP related/CMP revealed short- and long-range integration interactions in copper dual damascene technology

摘要

For material removal, Cu-CMP combines chemical and mechanical action. Its process sequence includes abrasive activation of the polishing surface, with subsequent chemical modification and final mechanical removal of surface compounds. Cu-CMP performance is considerably affected by distribution of Cu properties both in macro- and in micro-scale for all three layers removed (barrier, seed Cu and bulk Cu), which, resulting from previous process steps, requires operation consistency across the whole back-end block. Extensive integration work still has to be done to tune design rules, deposition, annealing and CMP, to make the whole back-end cluster self-consistent.