Illumination source for an inspection apparatus, inspection apparatus and inspection method
US10649344B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 2017 |
| Grant date | May 12, 2020 |
| Priority date | — |
| Expiry date | Oct 23, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/354
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is an illumination source apparatus comprising a high harmonic generation medium, a pump radiation source and a spatial filter. The pump radiation source emits a beam of pump radiation having a profile comprising no pump radiation in a central region of the beam and excites the high harmonic generation medium so as to generate high harmonic radiation. The pump radiation and the generated high harmonic radiation are spatially separated beyond the focal plane of the beam of pump radiation. The spatial filter is located beyond a focal plane of the beam of pump radiation, and blocks the pump radiation. Also disclosed is a method of generating high harmonic measurement radiation optimized for filtration of pump radiation therefrom.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.