Polishing slurry and method of reclaiming wafers
US7452481B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | May 16, 2005 |
| Grant date | Nov 18, 2008 |
| Priority date | — |
| Expiry date | May 16, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02079
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The polishing slurry contains monoclinic zirconium oxide particles having a crystallite size of 10 to 1,000 nm and an average particle diameter of 30 to 2,000 nm in an amount of 1 to 20 weight %, a carboxylic acid having three or more carboxyl groups in the molecule, and a quaternary alkylammonium hydroxide, and has a pH of 9 to 12. The method of reclaiming wafers comprises a step of polishing used test wafers by using the polishing slurry above and removing the films formed on the wafers and the degenerated layers formed on the wafer surfaces, a step of mirror-polishing at least one side of the wafers, and a step of cleaning the wafers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.