Tunable wavelength illumination system
US8508736B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 31, 2010 |
| Grant date | Aug 13, 2013 |
| Priority date | — |
| Expiry date | May 30, 2031 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7065
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lithographic apparatus has an alignment system including a radiation source configured to convert narrow-band radiation into continuous, flat and broad-band radiation. An acoustically tunable narrow pass-band filter filters the broad-band radiation into narrow-band linearly polarized radiation. The narrow-band radiation may be focused on alignment targets of a wafer so as to enable alignment of the wafer. In an embodiment, the filter is configured to modulate an intensity and wavelength of radiation produced by the radiation source and to have multiple simultaneous pass-bands. The radiation source generates radiation that has high spatial coherence and low temporal coherence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.