Following the Ta-Barrier etch in the bond pad module, the wafer surface contains residual photoresist, hardened etch polymers, and reactive halogen species P4.This Ashing and Strip/Clean step is mandatory to completely remove these organic and inorganic contaminants before the subsequent ILD 6-3 deposition (Engineering Practice).Unlike intermediate via cleans (such as steps #11, #17, or #32) which typically clear homogeneous dielectric bottoms, this specific step must handle a fully exposed meta