A method of passivating copper interconnects is disclosed. A freshly electrodeposited copper interconnect such as formed as via/trench structures in semiconductor manufacturing is chemically converted to passivating surface of copper tungstate or copper chromate either through MOCVD reaction with vapors of tungsten or chromium alkoxides, or by pyrolytic reaction with tungsten or chromium carbonyl in the presence of O.sub.2. The copper interconnect having the formed passivation service is then chemically mechanically polished. The process can be used with various manufacturing processes, including single and dual damascene processes.