This step occurs immediately after W CMP and TiN/Ti CMP for the contact layer, preparing the surface for Metal 0 (MET0) W Deposition A1.The primary objective is to remove residual slurry abrasives, pad debris, and metallic contaminants generated during the planarization of the tungsten plugs and barrier metals P1.If these contaminants are not rigorously removed, they can act as leakage paths or prevent proper ohmic contact of the subsequent MET0 layer P1.Unlike STI CMP post-cleaning which primar