Abstract
Structure sizes of ∼180 nm are now standard in microelectronics, and state-of-the-art fabrication techniques can reduce these to just a few tens of nanometres (ref. 1). But at these length scales, the strain induced at interfaces can locally distort the crystal lattice, which may in turn affect device performance in an unpredictable way. A means of non-destructively characterizing such strain fields with high spatial resolution and sensitivity is therefore highly desirable. One approach is to use Raman spectroscopy2, but this is limited by the intrinsic ∼0.5-µm resolution limit of visible light probes. Techniques based on electron-beam diffraction can achieve the desired nanometre-scale resolution. But either they require complex sample preparation procedures3 (which may alter the original strain field) or they are sensitive to distortional (but not dilational) strain within only the top few tens of nanometres of the sample surface4,5. X-rays, on the other hand, have a much greater penetration depth, but have not hitherto achieved strain analysis with sub-micrometre resolution6. Here we describe a magnifying diffraction imaging procedure for X-rays which achieves a spatial resolution of 100 nm in one dimension and a sensitivity of 10-4 for relative lattice variations. We demonstrate the suitability of this procedure for strain analysis by measuring the strain depth profiles beneath oxidized lines on silicon crystals.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
ESPRIT, Microelectronics Advanced Research Initiative (MEL-ARI). This document is located at http://www.cordis.lu/esprit/src/melop-rm.htm. It was last updated on 11 January 2000.
De Wolf, I., Norstrom, H. & Maes, H.E. Process-induced mechanical stress in isolation structures studied by micro-Raman spectroscopy. J. Appl. Phys. 74, 4490–4500 (1993).
Armigliato, A. et al. Strain measurements in thin film structures by convergent beam electron diffraction. J. Phys. III 7, 2375–2381 (1997).
Harland, C. J., Akhter, P. & Venables, J. A. Accurate microcrystallography at high spatial resolution using electron back–scattering patterns in a field emission gun scanning electron microscope. J. Phys. E 14, 175–182 (1981)
Wilkinson, A. J. Measurement of elastic strains and small lattice rotations using electron back scatter diffraction. Ultramicroscopy 62, 237–247 (1996)
Wang, P. C., Cargill III, G. S., Noyan, I. C. & Hu, C.-K. Electromigration-induced stress in aluminum conductor lines measured by x-ray microdiffraction. Appl. Phys. Lett. 72, 1296–1298 (1998).
Spiller, E. & Segmueller, A. Propagation of x-rays in waveguides. Appl. Phys. Lett. 24, 60–61 (1974).
Jark, W. et al. Properties of a submicrometer x-ray beam at the exit of a waveguide. J. Appl. Phys. 80, 4831–4836 (1996).
Wang, J., Bedzyk, M. J. & Caffrey, M. Resonance-Enhanced X-rays in thin films: a structure probe for membranes and surface layers. Science 258, 775–778 (1992).
Yariv, A. Quantum Electronics, 3rd edn, 115–129 (Wiley, & Sons, New York, 1989).
Cedola, A. Production de Faisceaux de Rayons X Submicroniques par Guide d'onde en Couches Minces. Thesis, Univ. de Grenoble (1999).
Lagomarsino, S. et al. Phase contrast hard x-ray microscopy with submicron resolution. Appl. Phys. Lett. 71, 2557–2559 (1997).
Appels, J. A., Kooi, E., Paffen, M. M., Schatorge, J. J. H. & Verkuylen, W. H. C. G. Local oxidation of silicon and its application in semiconductor-device technology. Philips Res. Rep. 25, 118–132 (1970).
Labiche, J. C., Segura-Puchades, D., Van Brussel, D. & Moy, J. P. FRELON camera: Fast Readout Low Noise. ESRF Newslett. 25, 41–43 (1996).
Fewster, P. F. in X-ray and Neutron Dynamical Diffraction: Theory and Applications (eds Authier, A., Lagomarsino, S. & Tanner, B. K.) 269–288 (Plenum, New York, 1996).
Hu, S. M. Stress-related problems in silicon technology. J. Appl. Phys. 70, R53–R80 (1991).
Jain, S. C., Maes, H. E., Pinardi, K. & De Wolf, I. Stresses and strains in lattice-mismatched stripes, quantum wires, quantum dots, and substrates in Si technology. J. Appl. Phys. 79, 8145–8165 (1996).
Landolt, H. H. & Bornstein, R. in Zahlenwerte und Funktionen aus Physik, Chemie, Astronomie, Geophysik und Technik (ed. Eucken, A.) (Springer-Verlag, Berlin, 1950).
Taupin, D. Theorie dynamique de la diffraction des rayons X par les cristaux deformes. Bull. Soc. Fr. Miner. Cristallogr. 87, 469–511 (1964).
Acknowledgements
We thank C. Kunz, C. Riekel, A. Freund and F. Comin for logistic support; O. Hignette, E. Boller, W. Ludwig and E. Chinchio for experimental support; ST Microelectronics for providing the samples; and G. Sandrin (Sincrotrone) for his technical advice. Part of this work was supported by the Ente Nazionale Energie Alternative (ENEA).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Di Fonzo, S., Jark, W., Lagomarsino, S. et al. Non-destructive determination of local strain with 100-nanometre spatial resolution. Nature 403, 638–640 (2000). https://doi.org/10.1038/35001035
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/35001035
This article is cited by
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
