Position measuring device, position measuring system, lithographic apparatus, and device manufacturing method
US6875992B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 2004 |
| Grant date | Apr 5, 2005 |
| Priority date | — |
| Expiry date | May 14, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7049
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A position measuring device includes a radiation source mounted on an isolated reference frame and a two-dimensional radiation detector mounted adjacent the radiation source. The object whose position is to be detected has a mirroring device, e.g. a retro-reflector, mounted on it so as to reflect light emitted from the radiation source along a return path that is parallel to but displaced from the incident light path. The amount of displacement is dependent on the position of the object and is measured by the two-dimensional detector. Three such devices can be combined in a system to measure the position of the object in all six degrees of freedom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.