A study of CMP Edge Profile for Production Wafers

Inhalt:
This paper describes the CMP edge profile control of production wafers. A production wafer’s CMP edge profile is affected by the edge step, different from a monitor wafer’s one, which can be controlled by zone pressure or retainer ring pressure. The edge step is caused by former etching processes with edge rinsed photo resist masks. The production wafer’s edge profile is determined by the planarity of the step. The edge profile can be improved by narrower edge rinse width of the photo resist or a high planarity CMP process such as solo pad CMP. Keywords: Chemical-mechanical Polishing, Edge profile, Retainer ring, Zone control, Planarity, Polishing pad