Measurement apparatus, exposure apparatus having the same, and device manufacturing method
US7952726B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2007 |
| Grant date | May 31, 2011 |
| Priority date | — |
| Expiry date | May 28, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/706
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A measurement apparatus includes a first mask that is arranged on an object plane of a target optical system, and has a window that transmits measurement light, a second mask that has a reflection surface for reducing coherence of the measurement light, and a diffraction grating configured to split the measurement light that has been reflected on the second mask, has passed the first mask and the target optical system, wherein a distance Lg between the diffraction grating and an image plane of the target optical system satisfies Lg=m·Pg2/λ where Pg is a grating pitch of the diffraction grating, λ is a wavelength of the measurement light, and m is an integer except for 0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.