A low specific surface area colloidal silica solution and a method for its preparation

A colloidal silica solution with low specific surface area was prepared by combining an ammonia/ammonium chloride buffer solution with a stepwise seed growth process. This method solves the problems of high equipment requirements, high energy consumption, and high production costs caused by high temperature and high pressure processing in existing technologies. It achieves high purity and narrow particle size distribution silica sol, which is suitable for semiconductor chemical mechanical polishing.

CN122646859APending Publication Date: 2026-08-28CNCEC HUALU NEW MATERIALS CO LTD
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Patent Information

Application Number
CN202611084924.3
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2026-07-21
Publication Date
2026-08-28

AI Technical Summary

Technical Problem

Existing technologies for preparing high-purity silica sols suffer from high specific surface area and loose structure, making it difficult to meet the requirements of semiconductor chemical mechanical polishing. Furthermore, the high-temperature and high-pressure processing results in high equipment requirements, high energy consumption, and high production costs, making it difficult to scale up production.

Method used

By combining an ammonia/ammonium chloride buffer catalytic system with a stepwise seed crystal growth process, and by controlling the reaction pH and adding silicon source in batches, a colloidal silica solution with low specific surface area is prepared, avoiding high temperature and high pressure treatment.

Benefits of technology

A colloidal silica solution with low specific surface area, high purity, and narrow particle size distribution was achieved, meeting the performance requirements of semiconductor chemical mechanical polishing, simplifying subsequent purification processes, and reducing production costs.

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Abstract

The application discloses a kind of low specific surface area colloidal silica solution and its preparation method, for the problems that the particle structure of the silica sol obtained by existing alkoxysilane hydrolysis method is loose, specific surface area is high, densification process depends on high temperature and high pressure, and impurities are easily introduced, the application uses ammonia / ammonium chloride buffer solution buffer system to stabilize reaction pH, combined with seed step growth process, with alkoxysilane as silicon source, drop by batch slowly, the system pH is regulated to 8.5~10 throughout the process, and the target product is prepared after incubation and maturation.The application can accurately control particle size, narrow particle size distribution, significantly reduce the specific surface area of product, the process is mild without high temperature and high pressure equipment, the product has high purity and good batch stability, and is suitable for high-end fields such as semiconductor chemical mechanical polishing.
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