Slurry for chemical-mechanical planarization of sapphire and method for manufacturing the same

Abstract

Taught herein is an aqueous chemical-mechanical polishing slurry, a method for manufacturing the same, and a method for using the same in the preparation of high precision finishing of a sapphire surface. The slurry comprises a chelating agent having 13 chelate rings, a strong propensity for complexation with aluminum ions and for forming a water-soluble chelate product. The removal rate can reach 10-16 μm/h, and the roughness can be reduced to 0.1 nm. The slurry components and their weight percentages are as follows: silica sol from about 1 wt. % to about 90 wt. %, alkali modifier from about 0.25 wt. % to about 5 wt. %, ether-alcohol activator from 0.5 wt. % to about 10 wt. %, chelating agent from about 1.25 wt. % to about 15 wt. %, and deionized water. Using such a slurry, high precision finishing of a sapphire surface can be achieved under relevant polishing conditions, which can satisfy the finishing requirements for industrial sapphire substrate. The slurry has the advantages of low cost, low roughness, and high removal rates, and it does not pollute the environment or damage the etching equipment.