Preparing method of silica slurry for wafer polishing
US6432151B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 22, 2000 |
| Grant date | Aug 13, 2002 |
| Priority date | — |
| Expiry date | Oct 29, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09G1/02
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Disclosed herein is a method of preparing silica slurry for wafer polishing. This method includes pre-treating relatively inexpensive and commercially available fumed or colloidal silica particles as a seed by a settling, a crushing using a ball mill and a paint shaker, and a sonication to produce an aqueous dispersion of the silica particles. The pre-treated silica particles are then combined with tetraethylorothosilicate as a precursor, an alcohol solvent and a base, and grown to a desired size by hydrolysis and polycondensation of the precursor, tetraethylorothosilicate. Then, the alcohol solvent, in which the silica particles are grown, are displaced with water by a vacuum distillation. The resulting aqueous dispersion of the grown silica dispersion is hydrothermally treated in an autoclave. Thus, this method allows the economical preparation of the spherical silica particles having a highly uniform size and a very high purity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.