Reticle and optical characteristic measuring method
US7375805B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2006 |
| Grant date | May 20, 2008 |
| Priority date | — |
| Expiry date | Dec 21, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/706
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wavefront aberration measuring method for measuring wavefront aberration of a projection optical system. The method includes providing a reticle having lines and spaces in which, with respect to a repetition direction thereof and from a center to a periphery, a pitch of the spaces is substantially constant while widths of the spaces gradually decrease and in which adjacent lines are not resolvable by the projection optical system, projecting light fluxes to the lines and spaces from different directions, whereby plural images of the lines and spaces are formed through the projection optical system, and detecting respective positions of the plural images and detecting, by use of the result of the detection, the wavefront aberration of the projection optical system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.