Electromigration in hybrid bonding interconnects for 3-D IC impact of the diffusion barrier

Electromigration experiments have been carried out on 3D interconnect structures with hybrid (Cu/SiO₂) bonding architectures. The investigated test structures highlighted that the Cu/Cu interface provides better electromigration performance than a Cu/SiO₂ interface. Moreover, the different Cu processes analyzed provide voiding mechanisms unchanged in comparison to the known damascene architecture.