Method of producing anionically modified colloidal silica
US11814294B2 · kind B2 · utility
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Key dates
| Filing date | May 27, 2021 |
| Grant date | Nov 14, 2023 |
| Priority date | — |
| Expiry date | Jun 18, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09K3/1436
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
There is provided a method of producing anionically modified colloidal silica capable of polishing a silicon nitride film at a high speed and suppressing a polishing speed of a silicon oxide film. A method of producing anionically modified colloidal silica includes ion exchanging raw colloidal silica using an ion exchange resin (ion exchange step); and anionically modifying ion-exchanged raw colloidal silica to obtain anionically modified colloidal silica (modification step).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.