The Ashing & Strip/Clean step following the ILD 3-2 Oxide Etch is a critical surface preparation phase in the bond pad module of the 40nm BSI CMOS image sensor flow P3.During the upstream reactive ion etching sequence that opens the deep bond pad via through multiple dielectric tiers, fluorocarbon (CFx) polymers are intentionally deposited on the etched sidewalls to ensure etching anisotropy and protect the dielectric from lateral degradation P1.Consequently, the resulting cavity is coated with