a process and structure for copper damascene interconnects including a tungsten - nitride barrier layer formed by atomic layer deposition is disclosed . the process method includes of forming a copper damascene structure by forming a first opening through a first insulating layer . a second opening is formed through a second insulating layer which is provided over the first insulating layer . the first opening being in communication with the second opening . a tungsten - nitride layer is formed in contact with the first and second openings . and , a copper layer is provided in the first and second openings . copper is selectively deposited using a selective electroless deposition technique at low temperature to provide improved interconnects having lower electrical resistivity and more electro / stress - migration resistance than conventional interconnects . additionally , metal adhesion to the underlying substrate materials is improved and the amount of associated waste disposal problems is reduced .