A high reliability copper dual-damascene interconnection with direct-contact via structure

Direct-contact via (DCV) structure in which a Cu via-plug is directly contacted to an interconnect is proposed for a high reliability and high performance Cu dual-damascene (DD) interconnection. Distribution of electromigration (EM) lifetime is dramatically reduced to 0.1 by eliminating void formation at the via-bottom. The developed technology improves the lifetime of the early failure by 5 times. It leads to 1.7 times higher clock frequency due to the higher current density.