Method of determining a value of a parameter of interest of a target formed by a patterning process
US10585048B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2019 |
| Grant date | Mar 10, 2020 |
| Priority date | — |
| Expiry date | Apr 16, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F9/7003
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Methods of determining a value of a parameter of interest are disclosed. In one arrangement, a symmetric component and an asymmetric component of a detected pupil representation from illuminating a target are derived. A first metric characterizing the symmetric component and a second metric characterizing the asymmetric component vary non-monotonically as a function of the parameter of interest over a reference range of values of the parameter of interest. A combination of the derived symmetric component and the derived asymmetric component are used to identify a correct value from a plurality of candidate values of the parameter of interest.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.