Optical measurement using fixed polarizer
US7791723B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 21, 2008 |
| Grant date | Sep 7, 2010 |
| Priority date | — |
| Expiry date | Oct 29, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/21
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Optical measurement method and systems employing a fixed polarizer are disclosed. In one embodiment, the method includes providing at least one optical detection system having a fixed polarizer having a first type polarization; providing a first target on a substrate and a second target on the substrate; optically measuring the first target and the second target using the at least one optical detection system with the first target being positioned at a right angle relative to the second target to obtain a first measurement with the first type polarization and a second measurement with a second type-equivalent polarization; and combining the first measurement and the second measurement to obtain the optical measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.