Low sodium, low metals silica polishing slurries
US5230833A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 19, 1992 |
| Grant date | Jul 27, 1993 |
| Priority date | — |
| Expiry date | Aug 19, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S516/928
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A colloidal silica slurry comprising: a low metals ammonium-stabilized silica sol having the following characteristics: SiO.sub.2 present in the range between about 15 to about 50 weight percent; a pH in the range between about 8.5 to about 11.3; a particle diameter in the range between about 4.0 to about 130 nm; aluminum, as Al, present in an amount less than about 100 ppm, based on SiO.sub.2 ; iron, as Fe, present in an amount less than about 50 ppm, based on SiO.sub.2 ; potassium, as K, present in an amount less than about 25 ppm, based on SiO.sub.2 ; and sodium, as Na, present in an amount less than about 500 ppm, based on SiO.sub.2 ; and a bactericide, a polishing rate accelerator which differs from the bactericide, and/or a sodium chlorite or sodium hypochlorite biocide. Optionally, a fungicide may also be added to the colloidal silica slurry to inhibit fungi growth.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.