Optimization of CMP process by detecting of oxide/nitride interface using IR system
US6261851A · kind A · utility
9Cited by
13References
15Claims
0Family size
Assignee
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Key dates
| Filing date | Sep 30, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Sep 30, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
In a chemical mechanical planarization assembly directed for the removal of oxide layers, which stop on films containing silicon nitride, a conventional polishing table is provided with a gas extraction unit which transmits a gas sample to an infrared spectrometer. The presence of ammonia in the slurry, which is generated when a stop layer containing silicon nitride is abraded under high pH conditions, can be detected using infrared spectroscopy and accordingly provides for an in situ endpoint detection method.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.