Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Nanophotonic identification of defects buried in three-dimensional NAND flash memory devices


Advances in nanophotonics and plasmonics have led to the creation of a variety of innovative optical components and devices. However, the development of powerful practical applications has so far been limited. Here we show that subsurface defects in three-dimensional NAND flash memory devices can be identified by exploiting the inherent hyperbolic metamaterial structure of the devices and associated nanophotonic interactions, such as the epsilon-near-zero effect and hyperbolic Bloch mode formation. By incorporating a hyperspectral imaging scheme into an industrial optical inspection tool, we experimentally demonstrate that a diffraction-assisted volume-plasmonic resonance provides a robust mechanism for identifying subsurface defects at a depth that is around ten times deeper than the conventional optical skin depth limit. Further spectral analysis in the longer-wavelength infrared region shows clear hyperbolic guided-mode-resonance signatures that would potentially allow defect identification over the entire device depth and on the scale of multiple micrometres.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Three-dimensional NAND flash memory architecture and optical defect-inspection system.
Fig. 2: Optical properties of tungsten and a W–SiO2 layer stack.
Fig. 3: Spectral response of a 3D NAND flash memory structure and resonant enhancement of the optical field penetration.
Fig. 4: Inspection test results on a 12-inch wafer specimen.
Fig. 5: FTIR measurement and predicted optical field penetration.

Similar content being viewed by others


  1. Russell, P. S. T. J. & Birks, T. A. in Photonic Band Gap Materials (ed. Soukoulis, C.M.) 71–91 (Springer Netherlands, 1996).

  2. Ding, Y. & Magnusson, R. Resonant leaky-mode spectral-band engineering and device applications. Opt. Express 12, 5661–5674 (2004).

    Article  Google Scholar 

  3. Ebbesen, T. W., Lezec, H. J., Ghaemi, H. F., Thio, T. & Wolff, P. A. Extraordinary optical transmission through sub-wavelength hole arrays. Nature 391, 667–669 (1998).

    Article  Google Scholar 

  4. Garcia-Vidal, F. J., Martin-Moreno, L., Ebbesen, T. W. & Kuipers, L. Light passing through subwavelength apertures. Rev. Mod. Phys. 82, 729 (2010).

    Article  Google Scholar 

  5. Yoon, J. W., Lee, J. H., Song, S. H. & Magnusson, R. Unified theory of surface-plasmonic enhancement and extinction of light transmission through metallic nanoslit arrays. Sci. Rep. 4, 5683 (2014).

    Article  Google Scholar 

  6. Campion, A. & Kambhampati, P. Surface-enhanced Raman scattering. Chem. Soc. Rev. 27, 241–250 (1998).

    Article  Google Scholar 

  7. Kauranen, M. & Zayats, A. V. Nonlinear plasmonics. Nat. Photon. 6, 737–748 (2012).

    Article  Google Scholar 

  8. Okamoto, K. et al. Surface-plasmon-enhaned light emitters based on InGaN quantum wells. Nat. Mater. 3, 601–605 (2004).

    Article  Google Scholar 

  9. Song, J.-H. et al. Fast and bright spontaneous emission of Er3+ ions in metallic nanocavity. Nat. Commun. 6, 7080 (2015).

    Article  Google Scholar 

  10. Hsu, C. W. et al. Observation of trapped light within the radiation continuum. Nature 499, 188–191 (2013).

    Article  Google Scholar 

  11. Yoon, J. W., Song, S. H. & Magnusson, R. Critical field enhancement of asymptotic optical bound states in the continuum. Sci. Rep. 5, 18301 (2015).

    Article  Google Scholar 

  12. Commercializing plasmonics. Nat. Photon. 9, 477 (2015).

  13. Guler, U., Kildishev, A. V., Boltasseva, A. & Shalaev, M. Plasmonics on the slope of enlightenment: the role of transition metal nitrides. Faraday Discuss. 178, 71–86 (2015).

    Article  Google Scholar 


  15. Weidanz, J. A. et al. Detection of human leukocyte antigen biomarkers in breast cancer utilizing label-free biosensor technology. J. Vis. Exp. 97, e52159 (2015).

    Google Scholar 

  16. Zhou, D. & Biswas, R. Photonic crystal enhanced light-trapping in thin film solar cells. J. Appl. Phys. 103, 093102 (2008).

    Article  Google Scholar 

  17. Hill, M. T. & Gather, M. C. Advances in small lasers. Nat. Photon. 8, 908–918 (2014).

    Article  Google Scholar 

  18. Challener, W. A. et al. Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer. Nat. Photon. 3, 220–224 (2009).

    Article  Google Scholar 

  19. Stokowski, S. & Vaez-Iravani, M. Wafer inspection technology challenges for ULSI manufacturing. In Characterization and Metrology for ULSI Technology: 1998 International Conference (eds Seiler, D. G. et al.) CP449 (AIP, 1998)

  20. Lee, S. K. et al. Investigation of novel inspection capability for 3D NAND device wordline inspection. In 25th Annual SEMI Advanced Semiconductor Manufacturing Conference 278–282 (IEEE, 2014).

  21. Tanaka, H. Bit cost scalable technology with punch and plug process for ultra high density flash memory. In IEEE Symposium on VLSI Technology 14–15 (2007).

  22. Rakić, A. D., Djurišić, A. B., Elazar, J. M. & Majewski, M. L. Optical properties of metallic films for vertical-cavity optoelectronic devices. Appl. Opt. 37, 5271–5283 (1998).

    Article  Google Scholar 

  23. Campione, S., Brener, I. & Marquier, F. Theory of epsilon-near-zero modes in ultrathin films. Phys. Rev. B 91, 121408(R) (2015).

    Article  Google Scholar 

  24. Rytov, S. M. Electromagnetic properties of a finely stratified medium. Sov. Phys. JETP 2, 466–475 (1956).

    MathSciNet  MATH  Google Scholar 

  25. Poddubny, A., Iorsh, I., Belov, P. & Kivshar, Y. Hyperbolic metamaterials. Nat. Photon. 7, 948–957 (2013).

    Article  Google Scholar 

  26. Ferrari, L., Wu, C., Lepage, D., Zhang, X. & Liu, Z. Hyperbolic metamaterials and their applications. Prog. Quantum Electron. 40, 1–40 (2015).

    Article  Google Scholar 

  27. Shekhar, P., Atkinson, J. & Jacob, Z. Hyperbolic metamaterials: fundamentals and applications. Nano Converg. 1, 14 (2014).

    Article  Google Scholar 

  28. Orlav, A. A., Zhukovsky, S. V., Iorsh, I. V. & Belov, P. A. Controlling light with plasmonic multilayers. Phot. Nano. Fund. Appl. 12, 213–230 (2014).

    Article  Google Scholar 


  30. Ferrari, L., Smalley, J. S. T., Faiman, Y. & Liu, Z. Hyperbolic metamaterials for dispersion-assisted directional light emission. Nanoscale 9, 9034 (2017).

    Article  Google Scholar 

  31. Wang, S. S. & Magnusson, R. Theory and applications of guided-mode resonance filters. Appl. Opt. 32, 2606–2613 (1993).

    Article  Google Scholar 

  32. Niraula, M., Yoon, J. W. & Magnusson, R. Single-layer optical bandpass filter technology. Opt. Lett. 40, 5062–5065 (2015).

    Article  Google Scholar 

  33. Niraula, M., Yoon, J. W. & Magnusson, R. Mode-coupling mechanisms of resonant transmission filters. Opt. Express 22, 25817–25829 (2014).

    Article  Google Scholar 

Download references


This work was supported by the i-TAP (Innovative-Technology Advancement Program) of SK hynix Inc. We thank S. J. Moon and G. Ahn for providing us with the FTIR spectrum analyser and associated discussions.

Author information

Authors and Affiliations



J.W.Y., S.-M.M., and S.H.S. conceived the original concept and initiated the work. S.M.M., Y.K., J.H., O.-J.K., and K.K. performed the optical inspection and FIB-SEM analysis. J.W.Y. and S.H.S. established the theoretical ground of the concept and performed the FTIR analysis. G.P.K., S.-M.M., and J.W.Y. performed the numerical analyses. All authors discussed the results. J.W.Y., S.H.S., and S.-M.M. wrote the manuscript. J.W.Y. and S.-M.M. contributed equally to this work.

Corresponding authors

Correspondence to Jae Woong Yoon, Seong-Min Ma or Seok Ho Song.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figures 1–6.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Yoon, J.W., Ma, SM., Kim, G.P. et al. Nanophotonic identification of defects buried in three-dimensional NAND flash memory devices. Nat Electron 1, 60–67 (2018).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing