Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-28T13:00:03.534Z Has data issue: false hasContentIssue false
  • English
  • Français

Spatial Resolution and Information Transfer in Scanning Transmission Electron Microscopy

Published online by Cambridge University Press:  03 January 2008

Yiping Peng ,
Mark P. Oxley ,
Andrew R. Lupini ,
Matthew F. Chisholm  and
Stephen J. Pennycook
Yiping Peng
Affiliation:
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6031, USA
Mark P. Oxley
Affiliation:
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6031, USA
Andrew R. Lupini
Affiliation:
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6031, USA
Matthew F. Chisholm
Affiliation:
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6031, USA
Stephen J. Pennycook
Affiliation:
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6031, USA
Get access

Abstract

The relation between image resolution and information transfer is explored. It is shown that the existence of higher frequency transfer in the image is just a necessary but not sufficient condition for the achievement of higher resolution. Adopting a two-point resolution criterion, we suggest that a 10% contrast level between two features in an image should be used as a practical definition of resolution. In the context of scanning transmission electron microscopy, it is shown that the channeling effect does not have a direct connection with image resolution because sharp channeling peaks do not move with the scanning probe. Through a quantitative comparison between experimental image and simulation, a Fourier-space approach is proposed to estimate defocus and sample thickness. The effective atom size in Z-contrast imaging depends on the annular detector's inner angle. Therefore, an optimum angle exists for the highest resolution as a trade-off between reduced atom size and reduced signal with limited information transfer due to noise.

Keywords

ADFSTEMresolutioninformation transfernoisedefocusthicknessdetector inner angle
Type
Research Article
Information
Microscopy and Microanalysis , Volume 14 , Issue 1: Special Issue: Materials Research in an Aberration-Free Environment , February 2008 , pp. 36 - 47
Copyright
© 2008 Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Allen, L.J., Findlay, S.D., Oxley, M.P. & Rossouw, C.J. (2003). Lattice-resolution contrast from a focused coherent electron probe. Part I. Ultramicroscopy 96, 47–63.Google Scholar
Allen, L.J. & Rossouw, C.J. (1990). Absorptive potentials due to ionization and thermal diffuse scattering by fast electrons in crystals. Phys Rev B 42, 11644–11654.Google Scholar
Beck, V. & Crewe, A.V. (1975). High resolution imaging properties of the STEM. Ultramicroscopy 1, 137–144.Google Scholar
Dellby, N., Krivanek, O.L., Nellist, P.D., Batson, P.E. & Lupini, A.R. (2001). Progress in aberration-corrected scanning transmission electron microscopy. J Electron Microsc 50, 177–185.Google Scholar
Den Dekker, A.J. & Van Den Bos, A. (1997). Resolution: A survey. J Opt Soc Am A 14, 547–557.Google Scholar
Dwyer, C. & Etheridge, J. (2003). Scattering of Å-scale electron probes in silicon. Ultramicroscopy 96, 343–360.Google Scholar
Fertig, J. & Rose, H. (1981). Resolution and contrast of crystalline objects in high-resolution scanning transmission electron microscopy. Optik 59, 407–429.Google Scholar
Findlay, S.D., Allen, L.J., Oxley, M.P. & Rossouw, C.J. (2003). Lattice-resolution contrast from a focused coherent electron probe. Part II. Ultramicroscopy 96, 65–81.Google Scholar
Haider, M., Uhlemann, S., Schwan, E., Rose, H., Kabius, B. & Urban, K. (1998). Electron microscopy image enhanced. Nature 392, 768–769.Google Scholar
Hänninen, P. (2002). Beyond the diffraction limit. Nature 419, 802.Google Scholar
Hÿtch, M.J. & Stobbs, W.M. (1994). Quantitative comparison of high-resolution TEM images with image simulations. Ultramicroscopy 53, 191–203.Google Scholar
Ishizuka, K. (1980). Contrast transfer of crystal images in TEM. Ultramicroscopy 5, 55–65.Google Scholar
Kirkland, E.J. (1998). Advanced Computing in Electron Microscopy. New York: Plenum Press.
Krivanek, O.L., Nellist, P.D., Dellby, N., Murfitt, M.F. & Szilagyi, Z. (2003). Towards sub-0.5 Å electron beams. Ultramicroscopy 96, 229–237.Google Scholar
Loane, R.F., Xu, P. & Silcox, J. (1992). Incoherent imaging of zone axis crystals with ADF STEM. Ultramicroscopy 40, 121–138.Google Scholar
Nellist, P.D., Chisholm, M.F., Dellby, N., Krivanek, O.L., Murfitt, M.F., Szilagyi, Z.S., Lupini, A.R., Borisevich, A., Sides, W.H. & Pennycook, S.J. (2004). Direct sub-Angstrom imaging of a crystal lattice. Science 305, 1741.Google Scholar
Nellist, P.D. & Pennycook, S.J. (1999). Incoherent imaging using dynamically scattered coherent electrons. Ultramicroscopy 78, 111–124.Google Scholar
O'Keefe, M.A. & Allard, L.F. (2004). A standard for sub-Ångström metrology of resolution in aberration-corrected transmission electron microscopes. Microsc Microanal 10(suppl. 2), 1002–1003.Google Scholar
O'Keefe, M.A., Allard, L.F. & Blom, D.A. (2005). HRTEM imaging of atoms at sub-Ångström resolution. J Electron Microsc 54, 169–180.Google Scholar
Peng, Y., Nellist, P.D. & Pennycook, S.J. (2004). HAADF-STEM imaging with sub-angstrom probes: A full Bloch wave analysis. J Electron Microsc 53, 257–266.Google Scholar
Pennycook, S.J. & Nellist, P.D. (1999). Z-contrast scanning transmission electron microscopy. In Impact of Electron and Scanning Probe Microscopy on Materials Research, Rickerby, D.G., Valdrè, G. & Valdrè, U. (Eds.), pp. 161–207. Boston, MA: Kluwer Academic Publishers.
Rayleigh, Lord (1879). Investigations in optics, with special reference to the spectroscope. Philos Mag 8, 261–274, 403–411, 477–486.Google Scholar
Sanchez, A.M., Galindo, P.L., Kret, S., Falke, M., Beanland, R. & Goodhew, P.J. (2006). An approach to the systematic distortion correction in aberration-corrected HAADF images. J Microsc 221, 1–7.Google Scholar
Scherzer, O. (1949). The theoretical resolution limit of the electron microscope. J Appl Phys 20, 20–29.Google Scholar
Sparrow, C.M. (1916). On spectroscopic resolving power. Astrophys J 44, 76–86.Google Scholar
Van Aert, S., Den Dekker, A.J., Van Dyck, D. & Van Den Bos, A. (2002). Optimal experimental design of STEM measurement of atom column positions. Ultramicroscopy 90, 273–289.Google Scholar
Van Dyck, D., Van Aert, S. & Den Dekker, A.J. (2004). Physical limits on atomic resolution. Microsc Microanal 10, 153–157.Google Scholar
Yu, Z., Batson, P.E. & Silcox, J. (2003). Artifacts in aberration-corrected ADF-STEM imaging. Ultramicroscopy 96, 275–284.Google Scholar