Skip to main content Accessibility help

Structural analysis of hydrogenated diamond-like carbon films from electron energy loss spectroscopy

  • Yaxin Wang (a1), Hsiung Chen (a1), R. W. Hoffman (a1) and John C. Angus (a2)


Electron energy loss spectral analysis of the π and (π + σ) electron plasma resonances are used to analyze the structure of hydrogenated diamond-like carbon (a-C:H) films. Energy loss peaks associated with the resonances of the π and (π + σ) plasmons in a-C:H are identified by comparison with reference spectra taken on natural diamond and on highly oriented pyrolytic graphite. The decrease in energy of the π plasmon with increasing hydrogen atom fraction provides direct experimental evidence that addition of hydrogen serves to reduce the density of π bonds in a-C:H. Under several important assumptions, the mass density, the sp3/sp2 site ratio, and the average coordination number are related to the resonance energies of the π and (π + σ) plasmons. The mass density of a-C:H samples inferred from the energy of (π + σ) electron plasma resonance is in the range from 1.46 to 1.69 g/cm3, which is in general agreement with an independent sink-float measurement. The ratio of sp3 (tetrahedral) to sp2 (trigonal) carbon sites increases from 0.29 to 0.75 and the average coordination number of each atomic site decreases from 2.6 to 2.3 as the hydrogen increases from 28 to 44 at.%. The fully constrained covalent network model is used to discuss the experimental results. The measured ratio of sp3/sp2 carbon sites and the average coordination numbers are in agreement with the predictions of the model, particularly at high hydrogen concentration.



Hide All
1Angus, J. C. and Hayman, C. C., Science 241, 913 (1988).
2Tamor, M. A. and Wu, C. H., J. Appl. Phys. 67, 1007 (1990).
3Tamor, M.A., Wu, C.H., Carter, R.O. III, and Lindsay, N.E., Appl. Phys. Lett. 55, 1388 (1989).
4Robertson, J., Adv. Phys. 35, 317 (1986).
5Beeman, D., Silverman, J., Lynds, R., and Anderson, M. R., Phys. Rev. B 30, 870 (1984).
6Dischler, B., Bubenzer, A., and Koidl, P., Solid State Commun. 48, 105 (1983).
7Galii, G., Martin, R. M., Car, R., and Pannello, M., Phys. Rev. Lett. 62, 555 (1989).
8Angus, J. C. and Jansen, F., J. Vac. Sci. Technol. A6, 1778 (1988).
9Kaplan, S., Jansen, F., and Machonkin, M., Appl. Phys. Lett. 47, 750 (1985).
10Grill, A., Meyerson, B. S., Patel, V.V., Reimer, J. A., and Petrich, M. A., J. Appl. Phys. 61, 2874 (1987).
11Angus, J. C., Koidl, P., and Domitz, S., Plasma Deposited Thin Films, edited by Mort, J. and Jansen, F. (CRC Press, Inc., Cleveland, OH, 1986), Chap. 4, p. 89.
12Lurie, P. G. and Wilson, J. M., Surf. Sci. 65, 476 (1977).
13Pepper, S.V., Surf. Sci. 123, 47 (1982).
14Balzarotti, A. and Piacentini, M., Electronic Structure and Electronic Transitions in Layered Materials, edited by Grasso, V. (D. Reidel Publishing Company, 1986), p. 338.
15Chen, H., “Preparation, Properties and Structure of Hydroge-nated Amorphous Carbon Films,” Doctoral Thesis, Department of Physics, Case Western Reserve University, Cleveland, OH, 1990.
16 For example, see Ashcroft, N.W. and Mermin, N. D., Solid State Physics (Saunders College, Philadelphia, PA, 1976), Chap. 1.
17Fink, J., Muller-Heinzerling, T., Pfluger, J., Bubenzer, A., Koidl, P., and Crecelius, G., Solid State Commun. 47, 687 (1983).
18Raether, H., Springer Tracts in Modern Physics 88 (1980).
19Savvides, N., J. Appl. Phys. 59, 4133 (1986).

Related content

Powered by UNSILO

Structural analysis of hydrogenated diamond-like carbon films from electron energy loss spectroscopy

  • Yaxin Wang (a1), Hsiung Chen (a1), R. W. Hoffman (a1) and John C. Angus (a2)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.