The Cu Seed deposition step bridges the highly resistive Ta-based barrier layer and the bulk electrochemical deposition (ECD) of Cu in the MET3 dual-damascene structure P3.After the Ta-based liner deposition, the dielectric trenches and vias are effectively sealed against metal diffusion, but they lack the highly conductive surface necessary for uniform electroplating P3.This Cu seed step establishes the continuous equipotential surface required for the subsequent M3 ECD process P3.Unlike the fi