Interference microscope with scan motion detection using fringe motion in monitor patterns
US8107084B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 30, 2009 |
| Grant date | Jan 31, 2012 |
| Priority date | — |
| Expiry date | Oct 27, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus includes an interferometer configured to generate an interference pattern by combining test light from a test object with reference light reflected from a reference object, the interferometer being further configured to direct at least a first part of a monitor test beam to the test object at a first incident angle and at least a second part of a monitor reference beam to the reference object at a second incident angle, and recombine the first part and the second part of the monitor beams after they reflect from the test and reference surfaces to interfere with one another and form a monitor pattern, where the first and second angles cause the monitor pattern to have spatial interference fringes, and wherein a change in the position of the interference fringes is indicative of a change in a relative position between the test and reference objects.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.