Imaging optical system and projection exposure installation for microlithography with an imaging optical system of this type
US10481500B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 3, 2011 |
| Grant date | Nov 19, 2019 |
| Priority date | — |
| Expiry date | Sep 2, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B17/0652
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An imaging optical system has a plurality of mirrors which image an object field in an object plane in an image field in an image plane. The imaging optical system has a pupil obscuration. The last mirror in the beam path of the imaging light between the object field and the image field has a through-opening for the passage of the imaging light. A penultimate mirror of the imaging optical system in the beam path of the imaging light between the object field and the image field has no through-opening for the passage of the imaging light. The result is an imaging optical system that provides a combination of small imaging errors, manageable production and a good throughput for the imaging light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.