Copper electroplating process for uniform across wafer deposition and void free filling on ruthenium coated wafers

摘要

Disclosed are methods of depositing and annealing a copper seed layer. A copper seed layer may be deposited on a ruthenium layer disposed on a surface of a wafer and on features in the wafer. The thickness of the ruthenium layer may be about 40 Angstroms or less. The copper seed layer may be annealed in a reducing atmosphere having an oxygen concentration of about 2 parts per million or less. Annealing the copper seed layer in a low-oxygen atmosphere may improve the properties of the copper seed layer.