Patent ID: 8440094
Filing Date: 2013-05-14
Classification: C09G,C09K,H01L

Abstract:
1. A method for chemical mechanical polishing of a substrate, comprising: providing a substrate, wherein the substrate comprises a polysilicon overburden deposited over silicon dioxide; providing a chemical mechanical polishing composition concentrate, wherein the chemical mechanical polishing composition concentrate consists essentially of: providing a first diluent; providing a second diluent; adding the first diluent to a first portion of the chemical mechanical polishing composition concentrate to form a first polishing formulation, wherein the first polishing formulation exhibits a pH of >4.2 to 11, wherein the first polishing formulation is tuned to exhibit a first polysilicon removal rate of ≧2,000 Å/min and a first polysilicon to silicon dioxide removal rate selectivity of 20:1 to 600:1; providing a chemical mechanical polishing pad; creating dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; dispensing the first polishing formulation onto the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate; removing the polysilicon overburden from the substrate; adding the second diluent to a second portion of the chemical mechanical polishing composition concentrate to form a second polishing formulation, wherein the second polishing formulation exhibits a pH of 2 to 4.2, wherein the second polishing formulation is tuned to exhibit a second polysilicon removal rate of ≧1,500 Å/min and a second polysilicon to silicon dioxide removal rate selectivity of 1:2 to 10:1; dispensing the second polishing formulation onto the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate; and, removing at least some more of the polysilicon and at least some of the silicon dioxide from the substrate.