Alignment measurement system, lithographic apparatus, and a method to determine alignment in a lithographic apparatus
US9046385B2 · kind B2 · utility
4Cited by
7References
13Claims
0Family size
Assignee
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Key dates
| Filing date | Aug 10, 2011 |
| Grant date | Jun 2, 2015 |
| Priority date | — |
| Expiry date | Jan 10, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7088
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An alignment measurement system measures an alignment target on an object. A measurement illuminates the target and is reflected. The reflected measurement beam is split and its parts are differently polarized. A detector receives the reflected measurement beam. A processing unit determines alignment on the basis of the measurement beam received by the detector. An alternative arrangement utilizes an optical dispersive fiber to guide a multi-wavelength measurement beam reflected from the object to a detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.