Position sensor, lithographic apparatus and method for manufacturing devices
US10527959B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 2017 |
| Grant date | Jan 7, 2020 |
| Priority date | — |
| Expiry date | Jun 30, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/3083
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An alignment sensor for a lithographic apparatus has an optical system configured to deliver, collect and process radiation selectively in a first waveband (e.g. 500-900 nm) and/or in a second waveband (e.g. 1500-2500 nm). The radiation of the first and second wavebands share a common optical path in at least some portion of the optical system, while the radiation of the first waveband is processed by a first processing sub-system and the radiation of the second waveband is processed by a second processing sub-system. The processing subsystems in one example include self-referencing interferometers. The radiation of the second waveband allows marks to be measured through an opaque layer. Optical coatings and other components of each processing sub-system can be tailored to the respective waveband, without completely duplicating the optical system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.