Illumination optical unit for EUV projection lithography
US9612537B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 2016 |
| Grant date | Apr 4, 2017 |
| Priority date | — |
| Expiry date | Jan 21, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B26/0825
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An EUV projection lithography illumination optical unit guides illumination light toward an object field, the illumination optical unit comprising. The unit includes: a first facet mirror comprising a plurality of first monolithic facets; and a second facet mirror downstream of the first facet mirror in a beam path of the illumination light, the second facet mirror comprising a plurality of second facets, each second facet being configured to contribute to imaging a corresponding first monolithic facet of the first facet mirror into the object field via an illumination channel. Individual parts of the first monolithic facets are configured so that illumination light is guided from the individual parts of the first monolithic facets toward different target locations on the corresponding second facet of the second facet mirror.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.