The RIE etch ILD 1-1 Etch is a critical step in the packaging and bondpad module for 40nm BSI CMOS Image Sensors P4.Following the sequential PMD etches, this step initiates the deep dielectric excavation required to form structural openings for metal-semiconductor contacts and external bonding pads T1.Unlike front-end oxide or nitride etches that pattern thin, individual films, this step must aggressively etch thick inter-layer dielectric (ILD) stacks while preventing over-etch damage to underly