The Post CMP Cleaning step in the MET1 module immediately follows the chemical mechanical planarization of the bulk copper interconnects and the underlying Ta-based barrier liner P2.This step exists to completely remove processing artifacts generated at the slurry–pad–wafer interface, thereby preparing a pristine, defect-free surface for the subsequent ILD 1-1 dielectric deposition P2.The preceding Cu CMP process utilizes aqueous hydrogen peroxide to oxidize the copper surface into mechanically