Endpoint detection by chemical reaction
US6180422A · kind A · utility
4Cited by
20References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | May 6, 1998 |
| Grant date | Jan 30, 2001 |
| Priority date | — |
| Expiry date | May 6, 2018 |
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. Also, detection of a substance at very low concentrations in a liquid, by extracting the substance present as a gas from the liquid and monitoring the gas to detect the substance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.