Methods for improving electromigration of copper interconnection structures are provided. In one embodiment, a method of annealing a microelectronic device including forming microelectronic features on a substrate, forming a contact structure over the microelectronic features, and forming a copper interconnection structure over the contact structure. A passivation layer is deposited over the copper interconnection structure and the substrate is subjected to a first anneal at a temperature of about 350° C. to 400° C. for a time duration between about 30 minutes to about 1 hour. The substrate is subjected to a second anneal at a temperature of about 150° C. to 300° C. for a time duration between about 24 to about 400 hours.