The Cu Seed deposition step in the MET1 module serves as the critical bridge between the highly resistive Ta-based diffusion barrier and the subsequent bulk copper electroplating process P3.Because electrochemical deposition relies on a continuous, highly conductive surface to serve as the cathode for uniform current distribution, a high-quality seed layer is mandatory P2.Without this seed layer, the subsequent plating process cannot initiate properly, leading to discontinuous growth or catastro