Advertisement

Journal of Materials Science

, Volume 29, Issue 7, pp 1920–1924 | Cite as

Measurement of foil thickness in transmission electron microscopy

  • Zhenpeng Pan
  • C. K. L. Davies
  • R. N. Stevens
Papers

Abstract

Methods for the measurement of the thickness of thin-foil specimens used in transmission electron microscopy are either difficult to carry out or have been subject to criticism. In particular, the contamination spot method is said to overestimate the thickness because the region of rapidly changing contrast marking the apparent edge of the spot is not on the foil surface but is on a broad contamination deposit whose thickness is changing much more slowly. A new method for measuring foil thickness is proposed, based on contamination deposits on the foil surfaces. The problems of the contamination spot method, in which the deposit is of circular form, are avoided by using one of the condenser lenses to focus the electron beam in a thin line on the foil during deposition. Adequate contrast can be obtained with a line whose width is one-third to one-fifth of the foil thickness and having a height equal to or less than its width. The error, being a fraction of the line width, is then very small. After rotation of the foil, the lines separate into two and the corresponding edges of the lines provide distinct features whose separation can be measured to determine thickness. The axis of rotation, perpendicular to which the separation of the lines has to be measured to calculate foil thickness, is determined by depositing two contamination lines at right angles. The method allows a number of measurements of thickness covering a relatively large area of foil to be made per contamination experiment. Near the edge of the foil, the upper and lower lines of contamination can join around the foil edge to form a U shape which can be used to measure thickness profile of the foil right up to the edge.

Keywords

Polymer Transmission Electron Microscopy Electron Beam Line Width Material Processing 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    G. W. Lorimer, G. Cliff and J. N. Clark, in “Developments in Electron Microscopy and Analysis” edited by D. L. Misell (Institute of Physics Bristol, 1976) p. 153.Google Scholar
  2. 2.
    P. M. Kelly, A. Jostons, R. G. Blake and J. G. Napier, Phys. Status solidi (a) 31 (1975) 771.CrossRefGoogle Scholar
  3. 3.
    G. Love, M. G. C. Cox and V. D. Scott, in “Developments in Electron Microscopy and Analysis” edited by D. L. Misell (Institute of Physics, Bristol, 1976) p. 347.Google Scholar
  4. 4.
    W. S. Miller and V. D. Scott, Met. Sci. J. 12 (1978) 95.CrossRefGoogle Scholar
  5. 5.
    V. D. Scott and G. Love, Mater. Sci. Technol. 3 (1987) 600.CrossRefGoogle Scholar
  6. 6.
    A. D. Romig and M. J. Carr, “Analytical Electron Microscopy—1984” (San Fransisco Press, San Fransisco, 1984) p. 111.Google Scholar
  7. 7.
    D. A. Rae, V. D. Scott and G. Love, in “Quantitative Microanalysis with High Spatial Resolution” edited by G. W. Lorimer (The Metals Society, London, 1981) p. 57.Google Scholar
  8. 8.
    N. Stenton, M. R. Notis, J. I. Goldstein and D. B. Williams, ibid.in “ p. 35.Google Scholar
  9. 9.
    Y. Kouh and E. L. Hall, General Electric Technical Information, Series 7 Report no. 82 CRD (1982) p. 156.Google Scholar

Copyright information

© Chapman & Hall 1994

Authors and Affiliations

  • Zhenpeng Pan
    • 1
  • C. K. L. Davies
    • 1
  • R. N. Stevens
    • 1
  1. 1.Department of MaterialsQueen Mary and Westfield CollegeLondonUK

Personalised recommendations