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Plasma Chemistry and Plasma Processing

, Volume 3, Issue 3, pp 329–336 | Cite as

Kinetic studies of SF6 plasmas during etching of Si

  • Werner W. Brandt
  • John J. Wagner
Article

Abstract

Mass spectrometric kinetic measurements were performed on a dc plasma during the etching of Si by SF6. Neutral plasma particles were permitted to effuse through an aperture in the cathode, via a differentially pumped section, into the ion source of the spectrometer, the sample being mounted on the cathode. The applied voltage was changed in steps, and the resulting mass signal transients for SF x + (x=0−5), F+, S2F 2 + , SiF+, and SiF 3 + were recorded. The SF 5 + , SF 4 + , and SF 3 + signals turned out to be essentially a measure of the unfragmented SF6 present in the plasma, while SF 2 + and SF+ responded in a complex way to the changes of applied voltage. The rate of SiF4 formation was not proportional to the concentration of F atoms or ions present. The S2F2 present in the plasma was probably formed from SF2 and SF radicals, mostly. Slow changes were observed in the signals representing SF 2 + , SF+, S+, F+, and S2F 2 + , presumably related to, or controlled by, gradual changes of the surface undergoing etching. The production and consumption rates of various species were seen to be nearly in balance, and strongly dependent on the applied voltage.

Key words

SF6 Si dc plasma etching kinetics transients mechanism 

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References

  1. 1.
    R. d'Agostino and D. L. Flamm,J. Appl. Phys. 52, 162 (1981).Google Scholar
  2. 2.
    G. Bruno, P. Capezzuto, F. Cramarossa, and R. d'Agostino,J. Fluor. Chem. 16, 209 (1980).Google Scholar
  3. 3.
    A. T. Bell, inTechniques and Applications of Plasma Chemistry, J. R. Hollahan and A. T. Bell, eds., Wiley-Interscience, New York (1974), Chapter 1.Google Scholar
  4. 4.
    D. L. Smith and R. H. Bruce,J. Electrochem. Soc. 129, 2045 (1982).Google Scholar
  5. 5.
    J. W. Coburn and H. F. Winters,J. Vac. Sci. Technol. 16, 391 (1979).Google Scholar
  6. 6.
    C. S. Korman, T. P. Chow, and D. H. Bower,Solid State Technol. 26, 115 (1983).Google Scholar
  7. 7.
    H. J. Tiller, J. Krause, and R. Voigt,Cryst. Res. Tech. 17, 821 (1982).Google Scholar
  8. 8.
    H. Toyodaet al., J. Appl. Phys. 20, 667 (1981).Google Scholar
  9. 9.
    K. M. Eisele,Rev. Phys. Appl. 13, 501 (1978).Google Scholar
  10. 10.
    J. Happel,J. Catal. 50, 429 (1977).Google Scholar
  11. 11.
    C. O. Bennett,Catal. Rev. 13, 121 (1976).Google Scholar
  12. 12.
    T. Furusawa, M. Suzuki, and J. M. Smith,Catal. Rev. 13, 43 (1976).Google Scholar
  13. 13.
    J. L. Mauer and J. S. Logan,J. Vac. Sci. Technol. 16, 404 (1979).Google Scholar
  14. 14.
    J. Visser,J. Vac. Sci. Technol. 19, 104 (1981).Google Scholar
  15. 15.
    J. J. Wagner and W. W. Brandt,Plasma Chem. Plasma Process. 1, 201 (1981).Google Scholar
  16. 16.
    P. Holzmann, Thesis, Innsbruck, Austria (1977); reported by H. Helm, T. D. Maerk, and W. F. Lindinger,Pure Appl. Chem. 52, 1752 (1980). Fig. 3Google Scholar
  17. 17.
    W. W. Brandt and D. L. Dovala,Appl. Spectrosc. 23, 604 (1969).Google Scholar
  18. 18.
    L. G. Christophorou, D. R. James, R. A. Mathis, I. Sauers, S. R. Hunter, M. O. Pace, D. W. Bouldin, S. M. Spyrou, A. Fatheddin, V. K. Lakdawala, J. L. Adcock, C. E. Easterly, and G. D. Griffin, ORNL Report TM-8368, Oak Ridge National Laboratory, July 1982.Google Scholar
  19. 19.
    U. Gerlach-Meyer,Surf. Sci. 103, 524 (1981).Google Scholar
  20. 20.
    V. H. Dibeler and F. L. Mohler,J. Res. Natl. Bur. Stand. 40, 25 (1948).Google Scholar
  21. 21.
    H. F. Winters and F. A. Houle,J. App. Phys. 54, 1218 (1983).Google Scholar

Copyright information

© Plenum Publishing Corporation 1983

Authors and Affiliations

  • Werner W. Brandt
    • 1
  • John J. Wagner
    • 1
  1. 1.Department of Chemistry and Laboratory for Surface StudiesUniversity of Wisconsin-MilwaukeeMilwaukee

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