Following the Upper OCL Coating Etch, this specific Ashing & Strip/Clean step is strictly required to remove the remaining photoresist and post-etch fluorocarbon residues before proceeding to the Bond Pad Opening 2 lithography P4.Unlike front-end ashing steps that clean robust inorganic dielectrics, this step is uniquely challenging because it must aggressively clean deep pad excavations without degrading the adjacent, optically sensitive on-chip lens (OCL) planarization layers P2.If the crossli