Contamination monitoring and control techniques for use with an optical metrology instrument
US7622310B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2006 |
| Grant date | Nov 24, 2009 |
| Priority date | — |
| Expiry date | May 14, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/94
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A technique is provided for generating and subsequently monitoring the controlled environment(s) within an optical metrology instrument in such a manner as to minimize absorbing species within the light path of the metrology instrument and to minimize the build-up of contaminants on the surfaces of optical elements that may result in performance degradation. Both evacuation and backfill techniques may be utilized together along with a monitoring technique to determine if the environmental is suitable for measurements or if the environment should be regenerated. The optical metrology instrument may be an instrument which operates at wavelengths that include vacuum ultra-violet (VUV) wavelengths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.