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Optics Express

Optics Express

  • Editor: Michael Duncan
  • Vol. 13, Iss. 18 — Sep. 5, 2005
  • pp: 6699–6708

Through-focus technique for nano-scale grating pitch and linewidth analysis

Yi-Sha Ku, An-Shun Liu, and Nigel Smith  »View Author Affiliations


Optics Express, Vol. 13, Issue 18, pp. 6699-6708 (2005)
http://dx.doi.org/10.1364/OPEX.13.006699


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Abstract

We report results of experimental investigations into a through-focus method relevant to sub-wavelength feature dimension measurement. The method linearizes the partial derivative values of a focus indicator with respect to minimum intensity order, and hence permits determination of pitch using a classical linear method. By evaluating the variations in focus indicator of the different captured images obtained at various focal positions, the through-focus curves show a response to sub-resolution changes in the grating structure. The results suggest that sub-wavelength feature dimensions can be evaluated using regular optical microscopes by implementing the through focus method.

© 2005 Optical Society of America

OCIS Codes
(050.1950) Diffraction and gratings : Diffraction gratings
(120.3940) Instrumentation, measurement, and metrology : Metrology

ToC Category:
Research Papers

History
Original Manuscript: July 1, 2005
Revised Manuscript: August 10, 2005
Published: September 5, 2005

Citation
Yi-Sha Ku, An-Shun Liu, and Nigel Smith, "Through-focus technique for nano-scale grating pitch and linewidth analysis," Opt. Express 13, 6699-6708 (2005)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-13-18-6699


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References

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