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Influence of adsorbates on electron emission from amorphous carbon under electron and swift heavy ion bombardment

Published online by Cambridge University Press:  19 November 2002

M. Caron ,
H. Rothard  and
A. Clouvas
M. Caron*
Affiliation:
PHILIPS GmbH, Philips Research Laboratories, Nano-Materials and Devices D303, Weisshausstrasse 2, 52066 Aachen, Germany
H. Rothard
Affiliation:
Centre Interdisciplinaire de Recherche Ions Lasers CIRIL (UMR 6637 CEA-CNRS-ISMRA), rue Claude Bloch, BP 5133, 14070 Caen Cedex 05, France
A. Clouvas
Affiliation:
Department of Electrical and Computer Engineering, Aristotelian University, GR-54006 Thessaloniki, Greece
*
[email protected]
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Abstract

Secondary Electron Emission (SEE) yield measurements have been used to investigate the desorption of nitrogen adsorbates from amorphous carbon (a-C) surfaces due to swift heavy ion impact. The fluence dependence of ion induced electron emission obeys an exponential decay law when the coverage rate is in the sub-mono-layer range. This reveals the relative contribution of the both emitting zones, the “clean” one (having the SEE properties of carbon) and the covered one (with a higher SEE coefficient) to the total measured yield. The mechanism for the SEE enhancement effect is connected to the surface termination. Nitrogen adsorbates are believed to provide surface states which generate a downwards energy band bending, which on relative scale pushes up the Fermi level towards the conduction band minimum, reducing the work function and increasing the SEE yield subsequently. A shoulder observed on the rising edge of the peak of the true SE peak is ascribe to the fraction of hydrogenated termination of a-C which exhibits a lower electron affinity.

Keywords

Type
Research Article
Information
The European Physical Journal - Applied Physics , Volume 21 , Issue 1 , January 2003 , pp. 9 - 16
Copyright
© EDP Sciences, 2003

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References

See, , e.g., J. Schou, Scanning Microsc. 2, 607 (1988)
D. Hasselkamp, H. Rothard, K.O. Groeneveld, J. Kemmler, P. Varga, H. Winter, in Particle Induced Electron Emission II, edited by G. Hoehler, E.A. Niekisch, Springer Tracks in Modern Physics (Springer, Heidelberg, 1991)
Caron, M., Beuve, M., Rothard, H., Gervais, B., Dubus, A., Roesler, M., Nucl. Instrum. Methods B 135, 436 (1998) CrossRef
Baragiola, R.A., J. Nucl. Mater. 126, 313 (1984) CrossRef
Arrale, A.M., Zhao, Z.Y., Kirchhoff, J.F., Marble, D.K., Weathers, D.L., McDaniel, F.D., Matteson, S., Nucl. Instrum. Methods B 89, 437 (1994) CrossRef
Rothard, H., Jung, M., Gervais, B., Grandin, J.P., Billebaud, A., Wünsch, R., Nucl. Instrum. Methods B 107, 108 (1996) CrossRef
Benka, O., Pürstinger, J., Koyama, A., Phys. Rev. A 58, 2978 (1998) CrossRef
Wittmaack, K., Surf. Sci. 419, 249 (1999) CrossRef
Caron, M., Haranger, F., Rothard, H., Ban d'Etat, B., Boduch, P., Clouvas, A., Potiriadis, C., Neugebauer, R., Jalowy, T., Nucl. Instrum. Methods B 179, 167 (2001) CrossRef
Caron, M., Clouvas, A., Neugebauer, R., Potiriadis, C., Rothard, H., Phys. Scripta T92, 205 (2001)
Caron, M., Rothard, H., Jung, M., Mouton, V., Lelievre, D., Beuve, M., Gervais, B., Nucl. Instrum. Methods B 146, 126 (1998) CrossRef
Hölzl, J., Jacobi, K., Surf. Sci. 14, 351 (1969) CrossRef
Himpsel, F.J., Knapp, J.A., Van Vechten, J.A., Eastman, D.E., Phys. Rev. B 20, 624 (1979) CrossRef
Pate, B.B., Surf. Sci. 165, 83 (1986) CrossRef
Geis, M.W., Twichell, J.C., Macaulay, J., Okano, K., Appl. Phys. Lett. 67, 1328 (1995) CrossRef
Amaratunga, G.A.J., Silva, S.R.P., Appl. Phys. Lett. 68, 2529 (1996) CrossRef
The electron affinity ( $\chi$ ) of a semiconductor is defined as the energy required to move an electron from the bottom of the conduction band to a distance macroscopically far from the surface, i.e. away from any image charge effect. The work function is defined as the difference between Fermi energy level and vacuum level. $\chi$ is independent in most cases of the Fermi level and can be regarded as a measure of the hetero-junction band off-set between the vacuum and the conduction band of the material (see Fig. 5)
Silva, S.R.P., Amaratunga, G.A.J., Thin Solids Films 270, 194 (1995) CrossRef
Modinos, A., Xanthakis, J.P., Appl. Phys. Lett. 73, 1874 (1998) CrossRef
Kaukonen, M., Nieminen, R.M., Pöykkö, S., Seitsonen, A.P., Phys. Rev. Lett. 83, 5346 (1999) CrossRef
D. Dijkamp, R.W.A. Schmitz, internal report (1991)
Bouchard, C., Carette, J.D., Surf. Sci. 100, 251 (1980) CrossRef
R.G. Forbes, in Proceedings of the 3rd European Field Emission Workshop, Alicante, Spain, November 2001 (to be published)