Colloidal silica polishing composition and method for manufacturing synthetic quartz glass substrates using the same
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsHarunobu Matsui, Daijitsu Harada, Masaki Takeuchi
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Abstract
A polishing composition comprising a colloidal dispersion of spherical silica particles and associated silica particles as abrasive is provided. When used in the step of polishing synthetic quartz glass substrates, the polishing composition ensures a higher polishing rate than conventional colloidal silica and is effective for preventing any microscopic defects on the substrate surface, thus providing the substrate with a high smoothness. The polishing composition can be used as the ceria replacement polishing composition for polishing a lapped surface.
Claims12
A colloidal silica polishing composition comprising a colloidal solution containing spherical colloidal silica particles and associated colloidal silica particles,
- wherein an amount of the spherical colloidal silica particles is 2 to 5 times an amount of the associated colloidal silica particles on a weight basis and a mixture of the spherical colloidal silica particles and the associated colloidal silica particles is contained in an amount of 35 to 50% by weight of the polishing composition.
Dependencies are inferred from the claim text.