Sensor, lithographic apparatus, and device manufacturing method
US11022902B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 2018 |
| Grant date | Jun 1, 2021 |
| Priority date | — |
| Expiry date | May 14, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70633
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention relates to a sensor comprising: a radiation source to emit radiation having a coherence length towards a sensor target; and a polarizing beam splitter to split radiation diffracted by the sensor target into radiation with a first polarization state and radiation with a second polarization state, wherein the first polarization state is orthogonal to the second polarization state, and wherein the sensor is configured such that after passing the polarizing beam splitter radiation with the first polarization state has an optical path difference relative to radiation with the second polarization state that is larger than the coherence length.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.