Eliminating internal reflections in an interferometric endpoint detection system
US11421977B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 2018 |
| Grant date | Aug 23, 2022 |
| Priority date | — |
| Expiry date | Oct 19, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J2237/334
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method is disclosed for operating an endpoint detection system of a processing chamber having a ceiling formed therein, a substrate support located internal to the processing chamber, and a substrate resting on the substrate support. A transparent panel is located in the ceiling of the processing chamber, the panel oriented at a first acute angle relative to the substrate and the substrate support. The transparent panel receives an incident light beam from the endpoint detection system at a second acute angle relative to the panel. The transparent panel transmits the incident light beam to the substrate within the processing chamber at an angle perpendicular to the substrate and the substrate support.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.