CHEMICAL MECHANICAL POLISHING COMPOSITION FOR POLISHING A SAPPHIRE SURFACE AND METHODS OF USING SAME

摘要

A method of polishing a sapphire substrate is provided, comprising: providing a substrate having an exposed sapphire surface; providing a chemical mechanical polishing slurry, wherein the chemical mechanical polishing slurry comprises, as initial components: colloidal silica abrasive, wherein the colloidal silica abrasive has a negative surface charge; and, wherein the colloidal silica abrasive exhibits a multimodal particle size distribution with a first particle size maximum between 2 and 25 nm; and, a second particle size maximum between 75 and 200 nm; optionally, a biocide; optionally, a nonionic defoaming agent; and, optionally, a pH adjuster. A chemical mechanical polishing composition for polishing an exposed sapphire surface is also provided.

主权项

1. A method of polishing a sapphire substrate, comprising:
providing a substrate having an exposed sapphire surface; providing a chemical mechanical polishing slurry having a pH of >8 to 12, wherein the chemical mechanical polishing slurry comprises, as initial components:
colloidal silica abrasive, wherein the colloidal silica abrasive has a negative surface charge; and, wherein the colloidal silica abrasive exhibits a multimodal particle size distribution with a first particle size maximum between 2 and 25 nm; and, a second particle size maximum between 75 and 200 nm;optionally, a biocide;optionally, a nonionic defoaming agent; and,optionally, a pH adjuster; providing a chemical mechanical polishing pad; creating dynamic contact at an interface between the chemical mechanical polishing pad and the substrate; and dispensing the chemical mechanical polishing slurry onto the chemical mechanical polishing pad at or near the interface between the chemical mechanical polishing pad and the substrate; wherein at least some sapphire is removed from the exposed sapphire surface of the substrate and wherein the chemical mechanical polishing slurry exhibits a sapphire removal rate of ≧14,000 Å/hr with a platen speed of 120 revolutions per minute, a carrier speed of 120 revolutions per minute, a chemical mechanical polishing slurry flow rate of 400 ml/min, a nominal down force of 34.3 kPa on a 300 mm polishing machine; and, wherein the chemical mechanical polishing pad is a polyurethane impregnated non-woven polishing pad.