Method of polishing using tunable polishing formulation

摘要

A process for chemical mechanical polishing of a substrate having a polysilicon overburden deposited over silicon nitride is provided using multiple dilutions of a chemical mechanical polishing composition concentrate to polish the substrate, wherein a first dilution of the concentrate used to polish the substrate is tuned to exhibit a first polysilicon removal rate and a first polysilicon to silicon nitride removal rate selectivity; and wherein a second dilution of the concentrate used to polish the substrate is tuned to exhibit a second polysilicon removal rate and a second polysilicon to silicon nitride removal rate selectivity.