Ultrapure colloidal silica for use in chemical mechanical polishing applications
US8211193B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 22, 2006 |
| Grant date | Jul 3, 2012 |
| Priority date | — |
| Expiry date | Nov 16, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3212
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of chemical mechanical polishing a surface of a substrate including the step of: contacting the substrate and a composition including a plurality of colloidal silica particles having less than 200 ppb of each trace metal impurity, excluding potassium and sodium, have less than 2 ppm residual alcohol and wherein the cumulative concentration of the trace metal, excluding potassium and sodium, is in the range from about 0.5 to about 5 ppm; and a medium for suspending the particles; wherein the composition is an ultrapure colloidal silica dispersion; and wherein the contacting is carried out at a temperature and for a period of time sufficient to planarize the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.