Inspection method and apparatus, lithographic apparatus, lithographic processing cell and device manufacturing method
US7701577B2 · kind B2 · utility
50Cited by
29References
13Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 21, 2007 |
| Grant date | Apr 20, 2010 |
| Priority date | — |
| Expiry date | Oct 3, 2028 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/4792
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention refers to the simultaneous measurement of four separately polarized beams upon diffraction from a substrate in order to determine properties of the substrate. Circularly or elliptically polarized light sources are passed via up to three polarizing elements. This polarizes the light sources by 0, 45, 90 and 135°. The plurality of polarizing beamsplitters replaces the use of a phase modulator, but enables the measurement of the intensity of all four beams and thus the measurement of the phase modulation and amplitude of the combined beams to give the features of the substrate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.