Microlithographic apparatus and method of changing an optical wavefront in such an apparatus
US10423082B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 9, 2014 |
| Grant date | Sep 24, 2019 |
| Priority date | — |
| Expiry date | Dec 4, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70891
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A microlithographic apparatus comprises an optical wavefront manipulator. The latter includes an optical element and a gas-tight cavity that is partly confined by the optical element or contains it. A gas inlet device directs a gas jet towards the optical element. The location, where the gas jet impinges on the optical element after it has passed through the cavity, is variable in response to a control signal supplied by a control unit. A gas outlet is in fluid connection with the vacuum pump so that, upon operation of the vacuum pump, the pressure within the cavity is less than 10 mbar even if the gas jet passes through the cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.