CHEMICAL MECHANICAL POLISHING COMPOSITION AND METHOD FOR PREVENTING POLISHING PAD GROOVE CLOGGING
An aqueous based chemical mechanical polishing composition for polishing a semiconductor substrate includes an abrasive having bimodal distributed colloidal silica particles which include elongated colloidal silica particles, polyvinyl alcohol 80% hydrolyzed to less than or equal to 90% hydrolyzed, an electrolyte and a pH greater than 7, and a method of polishing the semiconductor substrate to planarize the substrate. The aqueous based chemical mechanical polishing composition and method inhibits polishing pad groove clogging during chemical mechanical polishing of the semiconductor substrates.
1 . A chemical mechanical polishing composition comprising water, an abrasive having bimodal distributed colloidal silica particles including elongated colloidal silica particles, polyvinyl alcohol 80% to less than or equal to 90% hydrolyzed, an electrolyte, and a pH greater than 7.
2 . The chemical mechanical polishing composition of claim 1 , wherein the polyvinyl alcohol is 80-89% hydrolyzed.
3 . The chemical mechanical polishing composition of claim 2 , wherein the polyvinyl alcohol is 87-89% hydrolyzed.
4 . The chemical mechanical polishing compositions of claim 1 , wherein a weight average molecular weight of the polyvinyl alcohol 80% to less than or equal to 90% hydrolyzed is 9000 g/mole or greater.
5 . The chemical mechanical polishing composition of claim 4 , wherein the weight average molecular weight is 12,000-150,000 g/mole.
6 . The chemical mechanical polishing composition of claim 1 , wherein the amount of polyvinyl alcohol 80% to less than or equal to 90% hydrolyzed is from 0.001-0.01 wt %.
7 . The chemical mechanical polishing composition of claim 1 , wherein the chemical mechanical polishing composition has a conductivity of 4 mS/cm and greater.
8 . The chemical mechanical polishing composition of claim 1 , wherein the pH is 8-12.
9 . The chemical mechanical polishing composition of claim 1 , wherein the bimodal distributed elongated colloidal silica particles have a first mode with a first particle size maximum of 50-100 nm and a second mode with a second particle size maximum of 100-200 nm.
10 . A method for chemical mechanical polishing a substrate comprising: providing a substrate, wherein the substrate comprises silicon oxide; providing a chemical mechanical polishing composition composed of water, an abrasive having bimodal distributed colloidal silica particles including elongated colloidal silica particles, polyvinyl alcohol 80% to less than 90% hydrolyzed, an electrolyte, optionally a biocide, optionally a surfactant, optionally, a pH adjusting agent, and a pH greater than 7; and
providing a chemical mechanical polishing pad with a polishing surface and grooves; creating dynamic contact at an interface between the polishing surface of the chemical mechanical polishing pad and the substrate with a down force of 20 to 35 kPa; and dispensing the chemical mechanical polishing composition onto the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate; and
wherein some of the silicon oxide is removed from the substrate.