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Surface Science Aspects of Contamination in Tem Sample Preparation

Published online by Cambridge University Press:  10 February 2011

John T. Grant
Affiliation:
Research Institute, University of Dayton, 300 College Park, Dayton OH 45469-0167
Scott D. Walck
Affiliation:
Materials Directorate, WIJMLBT, 2941 P St. Ste. 1, Wright-Patterson AFB, OH 45433-7750
Frank J. Scheltens
Affiliation:
UES, Inc., 4401 Dayton-Xenia Rd., Dayton, OH 45432
Andrey A. Voevodin
Affiliation:
Materials Directorate, WIJMLBT, 2941 P St. Ste. 1, Wright-Patterson AFB, OH 45433-7750
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Abstract

With the advent of the modem analytical electron microscope with its ultrahigh vacuum conditions, extremely high current density in a very small probe, and its light element analysis capability, it is imperative that contamination of the TEM sample, particularly by hydrocarbons, is eliminated. The degree of cleanliness required for analysis using surface sensitive techniques is also much greater than for other forms of analysis. Contamination of samples can occur (a) prior to analysis, due to the way samples are prepared or handled, or (b) during analysis. Examples of surface contamination prior to analysis and during analysis will be given, in order to illustrate their effect on an analysis.Polished Si, Ni, and Ti bulk samples and pre-thinned TEM Ni and Ti samples were intentionally contaminated by two methods. One set of samples was put on a liquid nitrogen cooled stage for one hour in a diffusion pumped Gatan Duomill in which the liquid nitrogen cold trap above the diffusion pump was intentionally left warm. The other set was contaminated by dipping them into a 100 ml solution of acetone containing 0.04 g of an acetone-soluble low temperature wax. Two commercially available plasma cleaners, specifically designed for eliminating hydrocarbon contamination, were used to clean the samples. The bulk samples were examined with x-ray photoelectron spectroscopy and the TEM samples were examined in a 200 keV analytical TEM. The results from these experiments will be discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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References

1. Annual Book of ASTM Standards, Vol. 03.06 (American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, Pennsylvania, 1997).Google Scholar
2. Park, Y.S., Grant, J.T. and Haas, T.W., J. Appl. Phys. 50, p. 809, 1979.Google Scholar
3. Hooker, M.P. and Grant, J.T., Surface Science 62, p. 21, 1977.Google Scholar
4. Coad, J.P. and Riviere, J.C., Surface Science 55, p.741, 1976.Google Scholar
5. Grant, J.T. and Hooker, M.P., Solid State Communications 19, p.1 11, 1976.Google Scholar
6. Hooker, M.P. and Grant, J.T., Surface Science 55, p. 741, 1976.Google Scholar
7. Chapman, B., Glow Discharge Processing, Wiley, New York, 1980.Google Scholar
8. Swift, J.D. and Schwar, M. J.R.E., Electric Probes for Plasma Diagnostics, Iliffe, London, 1970.Google Scholar
9. Mattox, D.M., Surface Preparation for Film and CoatingDeposition Processes, in Handbook of Deposition Technologies for Films and Coatings, Bunshah, R.T., ed., Noyes Publications, Park Ridge, NJ, 1994.Google Scholar
10. McCaffrey, J. P., Ultramicroscopv, 38, p. 149, 1991.Google Scholar
11. McCaffrey, J. P., Specimen Preparation for Transmission Electron Microscopy III, Materials Research Society Symposium Proceedings., Vol.254, p. 109, 1992.Google Scholar
12. McCaffrey, John P., Microscopy Research and Technique, 24, p. 180, 1993.Google Scholar
13. Roberts, Shane P., Walck, Scott D., Grant, John T., and Zaluzec, Nestor J., Applications of Reactive Gas Plasma Cleaning Technology in Minimizing Contamination of Specimens During Transmission and Analytical Electron Microscopy, Roberts, Shane P., Walck, Scott D., Grant, John T., Zaluzec, Nestor J., these Proceedings of the Spring 1997 Materials Research Society Meeting, San Francisco, CA, 1997.Google Scholar