Wavefront aberration measuring method, mask, wavefront aberration measuring device, exposure apparatus, and device manufacturing method
US8077391B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 2009 |
| Grant date | Dec 13, 2011 |
| Priority date | — |
| Expiry date | Jun 27, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F1/44
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A wavefront aberration measuring device includes a mask placed in an object plane of a to-be-tested optical system and having a pattern including a pinhole producing a spherical wave and adjoining diffraction gratings each ruled with lines oriented in a direction different from the other; an illumination optical system that illuminates an area of the mask with light emitted from a light source; a light splitter that splits the light from the pattern transmitted through the to-be-tested optical system; an image pickup unit that takes an image of interference fringes produced by the split light, the image being used in measuring wavefront aberration of the to-be-tested optical system; a detector that detects respective light quantities of respective diffracted beams from the respective illuminated diffraction gratings; and a control unit that controls alignment of the illuminated area of the mask and the pattern in accordance with a detection result.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.