Illumination source for an inspection apparatus, inspection apparatus and inspection method
US10451559B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 2018 |
| Grant date | Oct 22, 2019 |
| Priority date | — |
| Expiry date | Aug 13, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/95676
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is an inspection apparatus and associated method for measuring a target structure on a substrate. The inspection apparatus comprises an illumination source for generating measurement radiation; an optical arrangement for focusing the measurement radiation onto said target structure; and a compensatory optical device. The compensatory optical device may comprise an SLM operable to spatially modulate the wavefront of the measurement radiation so as to compensate for a non-uniform manufacturing defect in said optical arrangement. In alternative embodiments, the compensatory optical device may be located in the beam of measurement radiation, or in the beam of pump radiation used to generate high harmonic radiation in a HHG source. Where located in the beam of pump radiation, the compensatory optical device may be used to correct pointing errors, or impart a desired profile or varying illumination pattern in a beam of the measurement radiation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.