High-definition vertical-scan interferometry
US7605925B1 · kind B1 · utility
9Cited by
14References
9Claims
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Key dates
| Filing date | Jun 23, 2006 |
| Grant date | Oct 20, 2009 |
| Priority date | — |
| Expiry date | Dec 24, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/2441
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A broadband interferometric vertical scan of a sample surface is performed to produce interference data in conventional manner. A coarse surface profile of the surface is obtained in real time using a conventional technique, such as a center-of-mass calculation. A fine surface map is obtained concurrently using a quadrature-demodulation algorithm applied in real time to the same interference data used for the coarse surface calculation. The fine surface map is then combined with the coarse surface profile using an unwrapping technique that produces a final surface map with sub-nanometer resolution within a large height range.
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