Lithographic overlay sampling
US9646896B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 2013 |
| Grant date | May 9, 2017 |
| Priority date | — |
| Expiry date | Mar 11, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/14
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Some embodiments of the present disclosure relate to a method of alignment which includes defining a plurality of fields on the face of a wafer, and organizing the plurality of fields into an orthogonal field structure and two or more continuous field structures. A first number of alignment structure positions are measured within each field of the two or more continuous field structures, and a second number of alignment structure positions are measured within each field of the orthogonal field structure, the second number being greater than the first number. The feature or layer is then aligned to the previously formed feature or layer based upon the measured alignment structure positions of the two or more continuous field structures and the orthogonal field structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.