Novel post electroplating in-situ rapid annealing process for advanced copper interconnect application

The room-temperature self-annealing behavior of electroplated (ECP) copper and its impact on device manufacturing has led to the investigation of a post ECP anneal process to stabilize copper film properties before CMP. A novel in-situ anneal chamber was developed to allow for rapid thermal annealing and cooling of ECP wafers on Applied Materials´ Electra^TM Cu Integrated ECP System. This paper reports a detailed study of this process, including the impact of anneal temperature, time, and ambient on film sheet resistance, reflectivity, microstructure, hardness, as well as CMP polishing rate. Process repeatability results from an extended reliability test of the anneal chamber integrated with the Electra^TM Cu ECP System are also presented