Position measurement of optical elements in a lithographic apparatus
US10908508B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2019 |
| Grant date | Feb 2, 2021 |
| Priority date | — |
| Expiry date | Nov 19, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B17/0678
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lithographic apparatus includes a projection system which includes a plurality of optical elements configured to project a beam of radiation onto a radiation sensitive substrate. The lithographic apparatus also includes a metrology frame structure which includes a part of one or more optical element measurement systems to measure the position and/or orientation of at least one of the optical elements. The plurality of optical elements, a patterning device stage, and a substrate stage are arranged such that, in a two dimensional view on the projection system, a rectangle is defined such that it envelops the plurality of optical elements, the patterning device stage, and the substrate stage. The rectangle is as small as possible. The metrology frame structure is positioned within the rectangle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.