Two-dimensional structure for determining an overlay accuracy by means of scatterometry
US7099010B2 · kind B2 · utility
11Cited by
19References
20Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Nov 25, 2002 |
| Grant date | Aug 29, 2006 |
| Priority date | — |
| Expiry date | Sep 28, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A two-dimensional periodic pattern that is symmetrical with respect to a first and a second direction allows the determination of an overlay accuracy that is obtained during the fabrication of the two-dimensional structure. Due to the symmetry of the structure, the overlay accuracy in the first direction may be determined on the basis of substantially the same reference data as used for the determination of the overlay accuracy of the second direction so that establishing libraries is simplified. Moreover, depending on the capability of the metrology tool, the overlay accuracy in both directions may be obtained simultaneously.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.