A CMP composition containing 5-aminotetrazole, e.g., in combination with oxidizing agent, chelating agent, abrasive and solvent and a method of use. Such CMP composition may be diluted during the CMP polish to minimize the occurrence of dishing or other adverse planarization deficiencies in the polished copper, even in the presence of substantial levels of copper ions in the CMP composition and at the copper/CMP composition interface during CMP processing.