Method of measuring a target, substrate, metrology apparatus, and lithographic apparatus
US10408754B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2017 |
| Grant date | Sep 10, 2019 |
| Priority date | — |
| Expiry date | Sep 7, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7026
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Disclosed is a method of measuring a target, an associated substrate, a metrology apparatus and a lithographic apparatus. In one arrangement the target comprises a layered structure. The layered structure has a first target structure in a first layer and a second target structure in a second layer. The method comprises illuminating the target with measurement radiation. Scattered radiation formed by interference between plural predetermined diffraction orders is detected. The predetermined diffraction orders are generated by diffraction of the measurement radiation from the first target structure and are subsequently diffracted from the second target structure. A characteristic of the lithographic process is calculated using the detected scattered radiation formed by the interference between the predetermined diffraction orders.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.