Overlay target geometry for measuring multiple pitches
US9709903B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2012 |
| Grant date | Jul 18, 2017 |
| Priority date | — |
| Expiry date | Apr 13, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70633
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An overlay target for use in imaging based metrology is disclosed. The overlay target includes a plurality of target structures including three or more target structures, each target structure including a set of two or more pattern elements, wherein the target structures are configured to provide metrology information pertaining to different pitches, different coverage ratios, and linearity. Pattern elements may be separated from adjacent pattern elements by non-uniform distance; pattern elements may have non-uniform width; or pattern elements may be designed to demonstrate a specific offset as compared to pattern elements in a different layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.