The wafer has recently completed the Metal 7 Al stack deposition, which includes a bottom Ta barrier, the bulk Al metal, and a top Ta liner (Engineering Practice).Prior to the Bond Pad photoresist coating, the wafer must undergo a Pre Litho Cleaning step to prepare the surface P1.This step is designed to eliminate airborne molecular contaminants, organic residues, and particulate matter that could interfere with photolithographic focus and resist adhesion P1.Unlike earlier front-end cleans, this