In advanced semiconductor metallization, copper is widely adopted as an interconnect material due to its low electrical resistivity and high electromigration resistance P1.However, copper is a highly reactive metal and a fast diffuser in silicon and dielectrics, where its presence can create deep trap levels that severely degrade device performance P2.To prevent this degradation, the Ta-based liner deposition step acts as a critical diffusion barrier P1.Situated immediately after the ILD trench/