Polishing composition and method for chemically mechanically polishing a substrate

Abstract

This application provides a polishing composition and a method for chemical mechanical polishing of a substrate, relating to the field of chemical mechanical polishing technology. The polishing composition comprises: colloidal silica abrasive particles with an average secondary particle size of 30-130 nm, a height difference modifier, a polishing accelerator, and a pH adjuster. The pH value of the polishing composition is 8-11, and the content of the colloidal silica abrasive particles is 0.5-10 wt%. The height difference modifier has at least one group capable of adsorbing silicon nitride and / or silicon oxide. By adding a height difference modifier to the polishing composition, some groups on the height difference modifier adsorb onto silicon nitride / silicon oxide, while the other part forms a relatively dense protective film on polycrystalline silicon, effectively reducing the number of dish-shaped depressions in the polycrystalline silicon and facilitating the acquisition of a highly flat wafer surface.

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