Chemical mechanical polishing method for STI

摘要

A chemical/mechanical polishing method for polishing an object to be polished with an irregular surface, having a substrate with convexities and concavities, a stopper layer formed on the convexities of the substrate, and an embedded insulating layer formed to cover the concavities of the substrate and the stopper layer, wherein the method is characterized comprising a first polishing step of flattening the embedded insulating layer using a slurry (A) which can maintain the polishing speed at 500 ANGSTROM /min or less and a second polishing step of further polishing the embedded insulating layer to cause the stopper layer on the convexities to be exposed using a slurry (B) which can maintain the polishing speed at 600 ANGSTROM /min or more. The method is useful for flattening wafers during shallow trench isolation (STI) in manufacturing semiconductor devices.