OSA's Digital Library

Optics Express

Optics Express

  • Editor: Andrew M. Weiner
  • Vol. 21, Iss. 21 — Oct. 21, 2013
  • pp: 24483–24489

Method for optical inspection of nanoscale objects based upon analysis of their defocused images and features of its practical implementation

M.V. Ryabko, S.N. Koptyaev, A.V. Shcherbakov, A.D. Lantsov, and S.Y. Oh  »View Author Affiliations

Optics Express, Vol. 21, Issue 21, pp. 24483-24489 (2013)

View Full Text Article

Enhanced HTML    Acrobat PDF (1362 KB)

Browse Journals / Lookup Meetings

Browse by Journal and Year


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools



A microscopic method to inspect isolated sub 100 nm scale structures made of silicon is presented. This method is based upon an analysis of light intensity distributions at defocused images obtained along the optical axis normal to the sample plane. Experimental measurements of calibrated lines (height 50 nm, length 100 μm, and widths of 40–150 nm in 10 nm steps) on top of a monocrystalline silicon substrate are presented. Library of defocused images of calibrated lines is obtained experimentally and numerically with accordance to experimental setup parameters and measurements conditions. Processing of the measured defocused images and comparison with simulated ones from library allow one to distinguish between objects with a 10 nm change in width. It is shown that influence of optical system aberrations must be taken into account in order to achieve coincidence between simulation and measured results and increase accuracy of line width inspection accuracy. The limits of accuracy for object width measurements using this optical method are discussed.

© 2013 Optical Society of America

OCIS Codes
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(120.5820) Instrumentation, measurement, and metrology : Scattering measurements
(180.0180) Microscopy : Microscopy
(260.0260) Physical optics : Physical optics
(050.6624) Diffraction and gratings : Subwavelength structures

ToC Category:
Instrumentation, Measurement, and Metrology

Original Manuscript: July 22, 2013
Revised Manuscript: September 6, 2013
Manuscript Accepted: September 7, 2013
Published: October 7, 2013

M.V. Ryabko, S.N. Koptyaev, A.V. Shcherbakov, A.D. Lantsov, and S.Y. Oh, "Method for optical inspection of nanoscale objects based upon analysis of their defocused images and features of its practical implementation," Opt. Express 21, 24483-24489 (2013)

Sort:  Author  |  Year  |  Journal  |  Reset  


  1. D. Herisson, D. Neira, C. Fernand, P. Thony, D. Henry, S. Kremer, M. Polli, M. Guevremont, and A. Elazami, “Spectroscopic ellipsometry for lithography front-end level CD control: a complete analysis for production integration,” Proceedings of SPIE Vol.5038, 264–273 (2003). [CrossRef]
  2. C. J. Raymond, M. Littau, R. Markle, and M. Purdy, “Scatterometry for shallow trench isolation (STI) process metrology,” Proc. SPIE4344, 716–725 (2001). [CrossRef]
  3. R. J. Hoobler and E. Apak, “Optical critical dimension (OCD) measurements for profile monitoring and control: applications for mask inspection and fabrication,” Proc. SPIE5256, 638–645 (2003). [CrossRef]
  4. I. T. R. S. Roadmap, http://www.itrs.net/Links/2006Update/2006UpdateFinal.htm
  5. R. M. Silver, R. Attota, M. Stocker, J. Jun, E. Marx, R. Larrabee, B. Russo, and M. Davidson, “Comparison of measured optical image profiles of silicon lines with two different theoretical models,” Proc. SPIE4689, 409–429 (2002). [CrossRef]
  6. R. Attota, R. M. Silver, M. T. Stocker, E. Marx, J.-S. J. Jun, M. P. Davidson, and R. D. Larrabee, “A new method to enhance overlay tool performance,” Proc. SPIE5038, 428–436 (2003). [CrossRef]
  7. A. Arceo, B. Bunday, V. Vartanian, and R. Attota, “Patterned Defect & CD Metrology by TSOM Beyond the 22 nm Node,” Proc. SPIE8324, 83240E (2012). [CrossRef]
  8. R. Attota, T. A. Germer, and R. M. Silver, “Through-focus scanning-optical-microscope imaging method for nanoscale dimensional analysis,” Opt. Lett.33(17), 1990–1992 (2008). [CrossRef] [PubMed]
  9. A. V. Arecchi, T. Messadi, and R. J. Koshel, Field Guide to Illumination (SPIE Press, 2007)
  10. A. Taflove and S. C. Hagness, Computational Electrodynamics: The Finite-Difference Time-Domain Method, 3rd ed., Norwood, (Artech House, Inc., 2005)

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.


Fig. 1 Fig. 2 Fig. 3
Fig. 4

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited