Lithographic apparatus and device manufacturing method
US7239370B2 · kind B2 · utility
5Cited by
2References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2003 |
| Grant date | Jul 3, 2007 |
| Priority date | — |
| Expiry date | Jul 14, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70983
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a projection system a pattern plane on a reticle is illuminated to have a projection image focussed on an image plane. The presence of a pellicle in the optical path causes a virtual shift of the position of the pattern plane on the reticle. Depending on the presence or absence of the pellicle the image plane of the projection image needs to be adapted for proper focussing. A compensator counteracts the virtual shift of pattern plane due to the pellicle, by shifting the position of the pattern plane.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.