Enhancing performance of overlay metrology
US12001148B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 2023 |
| Grant date | Jun 4, 2024 |
| Priority date | — |
| Expiry date | Feb 27, 2043 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/45
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method includes generating a sequence of images of a semiconductor wafer from first and second detectors. The first detector images the wafer with first imaging parameters and the second detector images the wafer with second imaging parameters. The first or second imaging parameters are varied across the sequence of images to provide variation at sites across the wafer. The method includes providing a metric indicative of center-of-symmetry variations of first and second target features as a function of the varied imaging parameters based on the sequence of images. The method includes identifying a landscape of values of the varied image parameters for which the metric are below a predefined limit. The method includes generating a recipe for metrology measurements in which the varied imaging parameters are set to values within the landscape. The method includes generating metrology measurements from a production wafer based on the recipe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.