Device metrology targets and methods
US10571811B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 2016 |
| Grant date | Feb 25, 2020 |
| Priority date | — |
| Expiry date | Dec 8, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D89/10
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Metrology methods and targets are provided, that expand metrological procedures beyond current technologies into multi-layered targets, quasi-periodic targets and device-like targets, without having to introduce offsets along the critical direction of the device design. Several models are disclosed for deriving metrology data such as overlays from multi-layered target and corresponding configurations of targets are provided to enable such measurements. Quasi-periodic targets which are based on device patterns are shown to improve the similarity between target and device designs, and the filling of the surroundings of targets and target elements with patterns which are based on device patterns improve process compatibility. Offsets are introduced only in non-critical direction and/or sensitivity is calibrated to enable, together with the solutions for multi-layer measurements and quasi-periodic target measurements, direct device optical metrology measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.