Illumination system for shaping extreme ultraviolet radiation used in a lithographic projection apparatus
US6498351B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 2000 |
| Grant date | Dec 24, 2002 |
| Priority date | — |
| Expiry date | Mar 9, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/702
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a lithographic projection apparatus, extreme ultraviolet radiation, e.g., of a wavelength of 13 nm, is generated by an undulator 10 in an electron storage ring. The radiation is collected by a first relay mirror 13, and an image of the source waist is formed at an intermediate plane. At the intermediate plane, a first scattering mirror 14 is provided to increase the divergence of the radiation beam in at least one plane. A second relay mirror 15 images the first scattering mirror onto the entrance pupil 18 of the projection system of the lithographic apparatus. A second scattering mirror 16 folds the projection beam onto the mask 17 and further increases the divergence of the radiation beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.