Lithographic apparatus and device manufacturing method
US7113259B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2005 |
| Grant date | Sep 26, 2006 |
| Priority date | — |
| Expiry date | Sep 6, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/2041
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a lithographic projection apparatus, a space between an optical element is filled with a first fluid and a second fluid separated by a transparent plate. The first and second fluids have different first and second indices of refraction, respectively. The first fluid is provided between a substrate and the transparent plate and has an index of refraction similar to the index of refraction of the substrate. The second fluid is provided between the transparent plate and the optical element and has an index of refraction similar to the index of refraction of the optical element. The transparent plate has a third index of refraction between the first and second indices of refraction and may be equal to the first index of refraction or the second index of refraction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.