Patent ID: 7736405

Claim:
A method of planarizing a wafer substrate having copper films deposited thereon, said method comprising: (a) contacting a copper layer with a first “1a” slurry composition to remove bulk copper, to yield a wafer substrate having remaining copper overburden thereon, said “1a” composition comprising the following composition ranges by weight, based on the total weight of the composition: oxidizing agent 0.1 to 30 wt. % passivating agent 0.01 to 10 wt. % chelating agent 0.1 to 25 wt. % and abrasive 0 to 30 wt. % wherein the “1a” composition is devoid of rheology agent; and (b) contacting the remaining copper overburden with a second “1b” composition to remove the remaining copper overburden and expose an underlying liner layer, said “1b” composition comprising the following composition ranges by weight, based on the total weight of the composition: oxidizing agent 0.01 to less than 30 wt. % passivating agent 0.01 to 10 wt. % chelating agent 0.1 to 25 wt. % and abrasive 0 to 30 wt. %, rheology agent 0.01 to 5 wt. % wherein the amount of oxidizing agent in said “1b” composition is less than that of “1a” composition such that the “1b” composition removes copper at a rate lower than that of formulation “1a.”