Inspection method and apparatus, and associated computer readable product
US8692994B2 · kind B2 · utility
43Cited by
4References
18Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Feb 23, 2011 |
| Grant date | Apr 8, 2014 |
| Priority date | — |
| Expiry date | Jun 7, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70625
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A system is configured to measure two separately polarized beams upon diffraction from a substrate in order to determine properties of a grating on a substrate. Linearly polarized light sources are passed via a fixed phase retarder in order to change the phase of one of two orthogonally polarized radiation beams with respect to the other of the two beams. The relative phases of the two radiation beams and other features of the beams as measured in a detector gives rise to properties of the substrate surface. The grating and the initial linear polarization of the radiation beam are angled non-orthogonally relative to each other.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.