Reference image grouping in overlay metrology
US11861824B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 25, 2023 |
| Grant date | Jan 2, 2024 |
| Priority date | — |
| Expiry date | Jan 25, 2043 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06T2207/20216
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An overlay metrology system may include a controller for receiving metrology data associated with a plurality of overlay targets on one or more samples; generating a reference metric for at least some of the plurality of overlay targets based on the metrology data, where the reference metric is associated with one or more properties of the respective overlay targets that contributes to overlay error; classifying the plurality of overlay targets into one or more groups based on the reference metrics calculated for the plurality of overlay targets; generating a reference image for at least some of the one or more groups; generating corrected metrology data using the associated reference image for at least some of the one or more groups; and generating overlay measurements for the plurality of overlay targets based on the corrected metrology data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.