Endpoint detection by chemical reaction
US6419785B1 · kind B1 · utility
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5Claims
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Key dates
| Filing date | Oct 3, 2000 |
| Grant date | Jul 16, 2002 |
| Priority date | — |
| Expiry date | Oct 3, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31053
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Detection of the endpoint for removal of a target film overlying a stopping film by removing the target film with a process that selectively generates a chemical reaction product (for example, ammonia when polishing a wafer with a nitride film in a slurry containing KOH) with either the target or stopping film, and monitoring the level of chemical reaction product as the target film is removed. The reaction product is extracted as a gas from the slurry and monitored using a threshold photoionization mass spectrometer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.