Magnetic filtration for slurry used in chemical mechanical polishing of semiconductor wafers
US6238279A · kind A · utility
7Cited by
10References
7Claims
0Family size
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Key dates
| Filing date | Jun 3, 1999 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Jun 3, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B57/02
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method and apparatus for filtering a slurry used in a chemical mechanical polishing apparatus is disclosed. Magnets are provided along the piping network between a slurry reservoir and the CMP apparatus. A magnet may also be placed adjacent to the slurry reservoir to prevent iron oxide particles from traveling with the slurry to the CMP apparatus. The magnets attract iron oxide particles from the slurry and remove those particles from the slurry prior to polishing. This reduces the amount of defects caused by the iron oxide particles in the slurry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.