Efficient phase matching algorithm for measurements of ultrathin indium tin oxide film thickness in white light interferometry

Optical Review volume 24, pages121–127(2017)Cite this article

Abstract

A novel method is proposed to measure the thickness of the indium tin oxide (ITO) film, which is less than 20 nm, using valid Fourier’s phase information of white light correlogram and curve matching algorithm. Based on the Fourier transform amplitude information, the valid phase distribution function that contains the thin transparent electrode ITO film thickness information has been successfully extracted. A curve matching algorithm based on standard deviation is employed to accurately calculate the thickness of such thin ITO films. The experimental results show that the thickness values were consistent with that determined using the stylus instruments, indicating that this method can be applied to measure the ITO film thickness ranging from 5 to 100 nm.

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References

  1. 1.

    Bendera, M., Seeliga, W., Daube, C., Frankenberger, H., Ocker, B., Stollenwerk, J.: Dependence of film composition and thicknesses on optical and electrical properties of ITO–metal–ITO multilayers. Thin Solid Films. 326, 67 (1998)

    ADS  Article  Google Scholar 

  2. 2.

    Minami, T.: Present status of transparent conducting oxide thin-film development for Indium-Tin-Oxide (ITO) substitutes. Thin Solid Films. 516, 5822 (2007)

    ADS  Article  Google Scholar 

  3. 3.

    Zhang, C., Zhao, D.W., Gu, D., Kim, H., Ling, T., Wu, Y.K.R., Guo L.J.: An ultrathin, smooth, and low-loss Al-doped Ag film and its application as a transparent electrode in organic photovoltaics. Adv. Mater. 26, 5696 (2014)

    Article  Google Scholar 

  4. 4.

    XuMatic: (ITO Glass, 2016). http://www.xumatic.com/index.php?route=product/category&path=25_31. Accessed 14 Mar 2016

  5. 5.

    Wyant, J.C.: White Light Interferometry. Proc. SPIE. 4737, 98 (2002)

    ADS  Article  Google Scholar 

  6. 6.

    Larkin, K.G.: Efficient nonlinear algorithm for envelope detection in white light interferometry. Opt. Soc. Am. 13, 832 (1996)

    ADS  Article  Google Scholar 

  7. 7.

    Chim, S.S.C., Kino, G.S.: Three-dimensional image realization in interference microscopy. Appl. Opt. 31, 2550 (1992)

    ADS  Article  Google Scholar 

  8. 8.

    de Groot, P., de Lega, X.C.: Signal modeling for low-coherence height-scanning interference microscopy. Appl. Opt. 43, 4821 (2004)

    ADS  Article  Google Scholar 

  9. 9.

    de Groot, P., de Lega, X.C., Kramer, J., Turzhitsky, M.: Determination of fringe order in white-light interference microscopy. Appl. Opt. 41, 4571 (2002)

    ADS  Article  Google Scholar 

  10. 10.

    Kim, S.W., Kim, G.H.: Thickness-profile measurement of transparent thin-film layers by white-light scanning interferometry. Appl. Opt. 38, 5968 (1999)

    ADS  Article  Google Scholar 

  11. 11.

    Chen, K., Lei, F., Itoh, M.: Measurement of ITO transparent electrode film thickness with white-light interferometer. Chin. Opt. 8, 567 (2015) (in Chinese)

    Article  Google Scholar 

  12. 12.

    Harasaki, A., Schmit, J., Wyant, J.C.: Improved vertical-scanning interferometry. Appl. Opt. 39, 2107 (2000)

    ADS  Article  Google Scholar 

  13. 13.

    Li, M.C., Wan, D.S., Lee, C.C.: Application of white-light scanning interferometer on transparent thin-film measurement. Appl. Opt. 51, 8579 (2012)

    ADS  Article  Google Scholar 

  14. 14.

    Geng, D.F., He, Y.J., Su, H.Y.: Study on the measurement of transparent step by white-light interferometer. Opt. Instrum. 35, 74 (2013)

    Google Scholar 

  15. 15.

    Sato, A.: Advanced metrology of surface texture by scanning white light interferometry. Surf. Finish. Soc. Jpn. 57, 554 (2006)

    Article  Google Scholar 

  16. 16.

    Ma, S.D., Quan, C.G., Zhu, R.H., Tay, C.J., Chen, L.: Surface profile measurement in white-light scanning interferometry using a three-chip color CCD. Appl. Opt. 50, 2246 (2011)

    ADS  Article  Google Scholar 

  17. 17.

    Kitagawa, K.: Thin-film thickness profile measurement by three-wavelength interference color analysis. Appl. Opt. 52, 1998 (2013)

    ADS  Article  Google Scholar 

  18. 18.

    Ogawa, H., Shimoyama, K., Fukunaga, M., Kitagawa, K., Sugiyama, S.: Simultaneous measurement of film thickness and surface profile of film-covered objects by using white-light interferometry. Soc. Instrum. Control Eng. 43, 71 (2007)

    Google Scholar 

  19. 19.

    Born, M., ‎Wolf, E.: Principles of optics. p. 64. Cambridge University Press, United Kingdom (1999)

    Google Scholar 

  20. 20.

    Roy, M., Cooper, I., Moore, P., Sheppard, C.J.R., Hariharan, P.: White-light interference microscopy: effects of multiple reflections within a surface film. Opt. Express 13, 164 (2005)

    ADS  Article  Google Scholar 

  21. 21.

    Debnath, S.K., Kothiyal, M.P.: Improved optical profiling using the spectral phase in spectrally resolved white-light interferometry. Appl. Opt. 45, 6965 (2006)

    ADS  Article  Google Scholar 

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Affiliations

  1. Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, 3058576, Japan

    Kai Chen, Feng Lei & Masahide Itoh

  2. School of Physics and Electronic Electrical Engineering, Huaiyin Normal University, Huaian, 223001, China

    Feng Lei

Authors
  1. Kai Chen
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  2. Feng Lei
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  3. Masahide Itoh
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Correspondence to Kai Chen.

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Chen, K., Lei, F. & Itoh, M. Efficient phase matching algorithm for measurements of ultrathin indium tin oxide film thickness in white light interferometry. Opt Rev 24, 121–127 (2017). https://doi.org/10.1007/s10043-017-0304-4

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Keywords

  • White light interferometry
  • Frequency domain analysis
  • Thin film thickness
  • Fourier analysis
  • Amplitude and phase information