The Post CMP Cleaning step in the MET2 module immediately follows the chemical mechanical planarization of the Copper (Cu) overburden and the Ta-based liner P2.Its primary function is to remove slurry abrasives, organic corrosion inhibitors, and metallic residues left on the wafer surface before the subsequent ILD 2-1 dielectric deposition P4.Unlike the STI CMP Post Cleaning which primarily deals with oxide and nitride surfaces, this back-end-of-line (BEOL) cleaning step must handle exposed, hig