Method and arrangement for determining the heating condition of a mirror in an optical system
US10161808B2 · kind B2 · utility
1Cited by
25References
27Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2013 |
| Grant date | Dec 25, 2018 |
| Priority date | — |
| Expiry date | Mar 18, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The invention concerns a method of and an arrangement for determining the heating condition of a mirror in an optical system, in particular in a microlithographic projection exposure apparatus. In an embodiment the mirror is an EUV mirror and a method according to the invention comprises the following steps: deflecting at least one input measuring beam on to the mirror; ascertaining at least one optical parameter of at least one output measuring beam produced from the input measuring beam after interaction with the mirror; and determining the heating condition of the mirror on the basis of the parameter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.