Measurement method of overlay mark
US9007571B2 · kind B2 · utility
5Cited by
5References
19Claims
0Family size
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Key dates
| Filing date | Aug 20, 2013 |
| Grant date | Apr 14, 2015 |
| Priority date | — |
| Expiry date | Nov 22, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/706845
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A measurement method of an overlay mark is provided. An overlay mark on a wafer is measured with a plurality of different wavelength regions of an optical measurement tool, so as to obtain a plurality of overlay values corresponding to the wavelength regions. The overlay mark on the wafer is measured with an electrical measurement tool to obtain a reference overlay value. The wavelength region that corresponds to the overlay value closest to the reference overlay value is determined as a correct wavelength region for the overlay mark.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.