Process-sensitive metrology systems and methods
US10216096B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 2016 |
| Grant date | Feb 26, 2019 |
| Priority date | — |
| Expiry date | Jun 6, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70641
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A lithography system includes an illumination source and a set of projection optics. The illumination source directs a beam of illumination from an off-axis illumination pole to a pattern mask. The pattern mask includes a set of pattern elements to generate a set of diffracted beams including illumination from the illumination pole. At least two diffracted beams of the set of diffracted beams received by the set of projection optics are asymmetrically distributed in a pupil plane of the set of projection optics. The at least two diffracted beams of the set of diffracted beams are asymmetrically incident on the sample to form a set of fabricated elements corresponding to an image of the set of pattern elements. The set of fabricated elements on the sample includes one or more indicators of a location of the sample along an optical axis of the set of projection optics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.