Method for forming thick copper self-aligned dual damascene

摘要

A method for forming a void free ultra thick dual damascene copper feature providing a semiconductor process wafer comprising via openings formed in a first undoped silicate glass (USG) layer the first USG layer having an overlying a second USG layer formed having a thickness of greater than about 1 micron and an overlying silicon oxynitride BARC layer; forming a trench opening having a width of greater than about 1 micron to encompass one of the via openings; forming a barrier layer to line the dual damascene opening; forming a copper seed layer having a thickness of from about 1000 Angstroms to about 2000 Angstroms; carrying out a multi-step electrochemical deposition (ECD); and, carrying out a two step copper annealing process.