Metrology targets with supplementary structures in an intermediate layer
US10551749B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 24, 2017 |
| Grant date | Feb 4, 2020 |
| Priority date | — |
| Expiry date | Feb 24, 2037 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70683
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Metrology targets, production processes and optical systems are provided, which enable metrology of device-like targets. Supplementary structure(s) may be introduced in the target to interact optically with the bottom layer and/or with the top layer of the target and target cells configurations enable deriving measurements of device-characteristic features. For example, supplementary structure(s) may be designed to yield Moiré patterns with one or both layers, and metrology parameters may be derived from these patterns. Device production processes were adapted to enable production of corresponding targets, which may be measured by standard or by provided modified optical systems, configured to enable phase measurements of the Moiré patterns.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.