Multi-function overlay marks for reducing noise and extracting focus and critical dimension information
US11448975B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 2021 |
| Grant date | Sep 20, 2022 |
| Priority date | — |
| Expiry date | Apr 9, 2041 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2223/54426
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An overlay mark includes a first, a second, a third, and a fourth component. The first component is located in a first region of the first overlay mark and includes a plurality of gratings that extend in a first direction. The second component is located in a second region of the first overlay mark and includes a plurality of gratings that extend in the first direction. The third component is located in a third region of the first overlay mark and includes a plurality of gratings that extend in a second direction different from the first direction. The fourth component is located in a fourth region of the first overlay mark and includes a plurality of gratings that extend in the second direction. The first region is aligned with the second region. The third region is aligned with the fourth region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.