Method and apparatus for detecting the endpoint of a chamber cleaning
US6534007B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 1, 1997 |
| Grant date | Mar 18, 2003 |
| Priority date | — |
| Expiry date | Aug 1, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/905
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for cleaning a CVD chamber including optoelectronic detection of the completion or endpoint of the cleaning procedure once a ratio of emission lines reaches a threshold value. The method comprises the steps of: providing a plasma of a cleaning gas into the chamber and creating a plasma from the cleaning gas. The intensity of emission lines of the cleaning gas and of at least one background gas in the chamber are monitored. A ratio of the intensity of the cleaning gas emission line to the intensity of the background gas emission line is determined and monitored as a function of time. The determined ratio is compared to a preset threshold calibration value. The flow of gas is controlled based on the comparing step. The apparatus includes a cleaning gas supply with a valved inlet providing an entrance to the interior of the chamber for passing cleaning gas to the interior of the chamber. A detector having an optical input is disposed for sensing the electromagnetic radiation. The detector has a first channel for detecting a relative intensity of an emission line corresponding to the cleaning gas and a second channel for detecting a relative intensity of the emis…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.