Method and apparatus for determining the endpoint in a plasma cleaning process
US6079426A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 2, 1997 |
| Grant date | Jun 27, 2000 |
| Priority date | — |
| Expiry date | Jul 2, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S156/916
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Apparatus and methods are disclosed for utilizing a plasma cleaning operation of a CVD system incorporating cleaning process endpoint detection. In one embodiment, the cleaning process is performed at a constant exhaust capacity and the endpoint detection is in response to a specified rate of change of chamber pressure. In another embodiment, a servo-controlled exhaust system maintains a controlled chamber pressure and the endpoint detection is in response to a specified control signal. In a preferred embodiment, nitrogen trifluoride is converted into a plasma containing free fluorine radicals in a magnetron-powered remote microwave plasma generator. The remotely produced free fluorine radicals are used to remove silicon nitride deposits from a substrate processing chamber. The use of such a remote plasma system provides an efficient cleaning process that takes as little as half the time compared to similar in situ plasma cleaning processes. The incorporation of endpoint detection provides optimal cleaning time for the remote plasma cleaning process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.