Polishing Composition for Selective Silicon Nitride Removal

The patent changes the chemical parameters of the polishing composition by introducing organic acid-immobilized silica and organopolysiloxane with hydrophilic groups. These parameter changes enable selective chemical interaction with silicon-nitrogen bonding materials, achieving controlled polishing speed ratios while maintaining broad material applicability through the versatile chemistry of the additives.

The polishing composition uses composite abrasive grains consisting of silica particles with immobilized organic acid groups. This composite structure combines the mechanical polishing capability of silica with the selective chemical etching capability of organic acids, enabling both high selectivity for silicon nitride and broad applicability to other semiconductor materials.

The patent achieves high polishing speed for silicon nitride while maintaining selectivity by changing the chemical composition parameters. The organic acid-immobilized silica provides strong chemical affinity to silicon-nitrogen bonding, dramatically increasing its polishing speed, while the organopolysiloxane additive further enhances this selective interaction, achieving both high productivity and manufacturing precision simultaneously.

The polishing composition exhibits local quality enhancement by concentrating its chemical reactivity specifically at silicon-nitrogen bonding interfaces. The organic acid groups and hydrophilic organopolysiloxane create localized chemical environments that accelerate polishing only where silicon-nitrogen bonds are present, leaving other materials relatively unaffected, thus achieving high speed with maintained selectivity.

The patent changes the surface chemistry parameters of the abrasive grains by immobilizing organic acid groups on silica particles. This parameter change transforms the polishing mechanism from purely mechanical to a combination of mechanical and chemical processes, significantly improving polishing efficiency while the controlled chemical reaction reduces surface defects by preventing random mechanical damage.

The patent partially replaces the conventional mechanical polishing mechanism with a chemical etching mechanism. The organic acid-immobilized silica and organopolysiloxane create chemical reactions that etch silicon-nitride bonds, substituting pure mechanical abrasion with a chemically-assisted process that is both more efficient and produces fewer surface defects.