Chemical mechanical polishing composition and method for polishing tungsten

摘要

A composition and method for tungsten is provided comprising: a metal oxide abrasive; an oxidizer; a tungsten removal rate enhancing substance according to formula I; and, water; wherein the polishing composition exhibits an enhanced tungsten removal rate and a tungsten removal rate enhancement.

主权项

1. A method of chemical mechanical polishing a substrate, comprising:
providing a polishing machine; providing a substrate, wherein the substrate comprises tungsten; providing a chemical mechanical polishing composition, wherein the chemical mechanical polishing composition, comprises:
a metal oxide abrasive;an oxidizer, wherein the oxidizer is selected from the group consisting of KIO3 and KIO4−;a tungsten removal rate enhancing substance according to formula I wherein R1, R2 and R3 are each independently selected from a C1-4 alky group; optionally, a pH adjusting agent; and,
water;wherein the chemical mechanical polishing composition has a pH of 1 to 5; wherein the chemical mechanical polishing composition exhibits a tungsten removal rate, WRR, of ≧2,000 Å/min; and, wherein the tungsten removal rate enhancing substance according to formula I imparts the chemical mechanical polishing composition with an enhanced tungsten removal rate, wherein the following expression is satisfied
WRR>WRR0 wherein WRR is the tungsten removal rate in Å/min for the chemical mechanical polishing composition and WRR0 is a tungsten removal rate in Å/min obtained under identical conditions except that the tungsten removal rate enhancing substance according to formula I is absent from the chemical mechanical polishing composition; and, wherein the chemical mechanical polishing composition exhibits a tungsten removal rate enhancement, ΔWRR, of ≧10% according to the following equation
ΔWRR=((WRR−WRR0)/WRR0)*100%; providing a chemical mechanical polishing pad; installing the chemical mechanical polishing pad and the substrate in the polishing machine; creating dynamic contact between the chemical mechanical polishing pad and the substrate; dispensing the chemical mechanical polishing composition in proximity to an interface between the chemical mechanical polishing pad and the substrate; wherein the chemical mechanical polishing composition comes into contact with tungsten of the substrate; and, wherein some tungsten is removed from the substrate.