SiCN and SiN polishing slurries and polishing methods using the same
AssigneeFujimi Incorporated
InventorsFusayo Saeki, Hooi-Sung Kim
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Abstract
A method is disclosed for polishing a wafer with a slurry. In the method, the wafer comprises at least one of silicon carbonitride (SiCN) and silicon nitride (SiN), and further comprises one or both of silicon dioxide (SiO2) and poly silicon, and a removal rate of SiCN is greater than a removal rate of poly silicon, and the removal rate of poly silicon is greater than a removal rate of SiO2, and where the slurry comprises up to about 15 wt % of surface-modified colloidal silica particles which have a primary particle size of less than about 35 nm, and the surface-modified colloidal silica particles comprise a plurality of acid moieties or salts thereof.
Claims8
A polishing slurry comprising up to about 15 wt % of surface-modified colloidal silica particles,
- wherein the surface-modified colloidal silica particles have an average primary particle diameter of less than about 35 nm, and the surface-modified colloidal silica particles comprise a plurality of acid moieties or salts of the acid moieties,
- wherein the slurry demonstrates that a removal rate of silicon carbonitride (SiCN) is greater than a removal rate of silicon nitride (SiN), the removal rate of SiCN is greater than a removal rate of poly silicon, and the removal rate of poly silicon is greater than a removal rate of silica (SiO2),
- wherein the slurry has a pH of less than about 6, and
- wherein the surface-modified colloidal silica particles are negatively charged.
Dependencies are inferred from the claim text.