CMP in-situ conditioning with pad and retaining ring clean
US6806193B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 2003 |
| Grant date | Oct 19, 2004 |
| Priority date | — |
| Expiry date | Jan 15, 2023 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC11D2111/22
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method for preconditioning a CMP polishing pad and retaining ring prior to semiconductor wafer polishing. In the method of the present invention, the retaining ring is lowered to contact the rotating polishing pad, and a cleaning chemistry of ammonium citrate is applied to the pad. In an alternative embodiment, the cleaning chemistry comprises an aqueous solution of ammonium citrate, and a surfactant and/or copper inhibitor. After a sustained preconditioning period in which the retaining ring and polishing pad are polished, the pad is rinsed, lowering particulate buildup on the pad between wafer polishing steps, and bringing defect levels into an equilibrium state prior to each wafer polishing step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.