Method for designing two-dimensional array overlay targets and method and system for measuring overlay errors using the same
US8321821B2 · kind B2 · utility
2Cited by
7References
8Claims
0Family size
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Key dates
| Filing date | Dec 28, 2009 |
| Grant date | Nov 27, 2012 |
| Priority date | — |
| Expiry date | Dec 9, 2030 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F30/39
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for designing a two-dimensional array overlay target comprises the steps of: selecting a plurality of two dimensional array overlay targets having different overlay errors; calculating a deviation of a simulated diffraction spectrum for each two-dimensional array overlay target; selecting an error-independent overlay target by taking the deviations of the simulated diffraction spectra into consideration; and designing a two dimensional array overlay target based on structural parameters of the error-independent overlay target.
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