Passivation of Dangling Bonds in Amorphous Si and Ge by Gas Adsorption

  • R. Tsu
  • D. Martin
  • J. Gonzalez-Hernandez
  • S. R. Ovshinsky
Part of the Institute for Amorphous Studies Series book series (IASS)


We have used molecular-beam deposition (MBD) with a base pressure of 10–10 torr to prepare a-Si and a-Ge at relatively low substrate temperatures. The films contain voids which can adsorb gases such as H2, F2, SiF4, GeF4, O2, etc. Due to the high reactivity of the dangling bonds present, these molecules are broken down to their atomic constituents, thereby passivating the dangling bonds. Further annealing is required to form proper chemisorption and drive the passivating agents into smaller or isolated voids. Typically a decrease of dark conductivity by as much as 8 orders of magnitude is observed accompanied by the appearance of few decades of photocurrent above the dark current under (Air Mass 1) AM1. For a-Ge, using a similar procedure, fluorine is more effective as a passivating agent than hydrogen.


Substrate Temperature Amorphous Silicon Dangling Bond Dark Conductivity Passivating Agent 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    R. C. Chittick, J. H. Alexander, and H. F. Sterling, J. Electrochem. Soc. 116, 77 (1969).CrossRefGoogle Scholar
  2. 2.
    S. R. Ovshinsky and A. Madan, Nature 276, 482 (1978).ADSCrossRefGoogle Scholar
  3. 3.
    W. Paul, A. J. Lewis, G. A. N. Connell, and T. D. Moustakes, Solid State Commun. 20, 969 (1976).ADSCrossRefGoogle Scholar
  4. 4.
    D. L. Miller, H. Lutz, H. Wiesmann, E. Rock, A. K. Ghosh, S. Ramamoorth, and M. Strongin, JAY, 49, 6192 (1978).Google Scholar
  5. 5.
    D. Kaplan, N. Sol, and G. Velesco, Appl. Phys. Lett. 33, 440 (1978).ADSCrossRefGoogle Scholar
  6. 6.
    J. Jang, J. H. Kang, and C. Lee, J. Non-Cryst. Solids 35 & 36, 313(1980).CrossRefGoogle Scholar
  7. 7.
    N. Kniffler, W. W. Múller, J. M. Pirrung, N. Hanisch, B. Schroder, and J. Geigu, J. Phys. (Paris), Colloq. 10, C4–811 (1981).Google Scholar
  8. 8.
    S. R. Ovshinsky and M. Izu, U.S. Patent No. 4217 374 (1980).Google Scholar
  9. 9.
    N. J. Shevchik and W. Paul, J. Non-Cryst. Solids 16, 55 (1974).ADSCrossRefGoogle Scholar
  10. 9a.
    B. G. Bagley, D. E. Aspres, A. C. Adams, and C. J. Mogeb, Appl. Phys. Lett. 38, 56(1981).ADSCrossRefGoogle Scholar
  11. 11.
    D. K. Biegelsen, R. A. Street, C. C. Tsai, and J. C. Knights, Phys. Rev. B 20, 4839(1979).ADSCrossRefGoogle Scholar
  12. 12.
    H. H. Madden, Surf. Sci. 105, 129 (1981).ADSCrossRefGoogle Scholar
  13. 13.
    R. E. Schlier and H. E. Farnsworth, J. Chem. Phys. 30, 917 (1959).ADSCrossRefGoogle Scholar
  14. 14.
    J. J. Lander and J. Morrison, J. Chem. Phys. 37, 727 (1962).ADSCrossRefGoogle Scholar
  15. 15.
    The role of an electric field in the surface reactivity was pointed out by J. H. Block. See for example, T. Sakata and J. H. Block, Surf. Sci. 130, 313 (1983).ADSCrossRefGoogle Scholar
  16. 16.
    R. Tsu, J. Gonzalez-Hernandez, S. S. Chao, and D. Martin, Appl. Phys. Lett. 48, 647 (1986).ADSCrossRefGoogle Scholar
  17. 17.
    J. G. Hernandez, D. Martin, S. S. Chao, and R. Tsu, Appl. Phys. Lett. 45, 101 (1984).ADSCrossRefGoogle Scholar
  18. 18.
    J. R. Woodyard, D. R. Bowen, J. Gonzalez-Hernandez, S. C. Lee, D. Martin, and R. Tsu, J. Appl. Phys. 57, 2243 (1985).ADSCrossRefGoogle Scholar
  19. 19.
    L. Voget-Grote, W. Kimmorle, R. Fischer, and J. Stake, Philos. Mag. B 41, 127(1980).Google Scholar
  20. 20.
    R. Tsu, J. Gonzalez-Hernandez, D. Martin, and S. R. Ovshinsky, U.S. Patent No. 4 569 697 (1986).Google Scholar
  21. 21.
    S. R. Ovshinsky, Proceedings of the International Ion Auger Congress, ISIAT and IPAT, Kyoto, 1983 (unpublished), p. 817.Google Scholar
  22. 22.
    R. Tsu, D. Martin, J. Gonzalez-Hernandez, and S. R. Ovshinsky (unpublished).Google Scholar

Copyright information

© Plenum Press, New York 1991

Authors and Affiliations

  • R. Tsu
    • 1
  • D. Martin
    • 1
  • J. Gonzalez-Hernandez
    • 1
  • S. R. Ovshinsky
    • 1
  1. 1.Energy Conversion Devices, Inc.TroyUSA

Personalised recommendations