Metrology sensor, lithographic apparatus and method for manufacturing devices
US10788766B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 6, 2018 |
| Grant date | Sep 29, 2020 |
| Priority date | — |
| Expiry date | Mar 6, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7065
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed is a metrology sensor apparatus and associated method. The metrology sensor apparatus comprises an illumination system operable to illuminate a metrology mark on a substrate with illumination radiation having a first polarization state and an optical collection system configured to collect scattered radiation, following scattering of the illumination radiation by the metrology mark. The metrology mark comprises a main structure and changes, relative to the first polarization state, at least one of a polarization state of a first portion of the scattered radiation predominately resultant from scattering by the main structure and a polarization state of a second portion of radiation predominately resultant from scattering by one or more features other than the main structure, such that the polarization state of the first portion of the scattered radiation is different to the polarization state of the second portion of the scattered radiation. The metrology sensor apparatus further comprises an optical filtering system which filters out the second portion of the scattered radiation based on its polarization state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.