Hydrogen Dissociation at Hot Filaments: Determination of Absolute Atomic Hydrogen Concentrations

  • L. Schäfer
  • U. Bringmann
  • C.-P. Klages
  • U. Meier
  • K. Kohse-Höinghaus
Part of the NATO ASI Series book series (NSSB, volume 266)


Several CVD methods, using thermal or plasma activation of the gas phase, are used for the formation of synthetic diamond films1,2. The deposition processes are performed at pressures of a few tens of mbar (microwave plasma-assisted CVD (MWPCVD)3 or hot filament-assisted CVD (HFCVD)4) to atmospheric pressures (plasma jets5 or flame synthesis6) with hydrocarbons and an abundance of molecular hydrogen in the gas phase. Although the detailed mechanisms are still in discussion, the importance of the presence of hydrogen for selective diamond formation is widely accepted. Atomic hydrogen, created by the activation of the gas atmosphere, can react with hydrocarbons to form hydrocarbon species like methyl or acetylene in the gas phase. These species are by some authors assumed to be key species in the process of diamond formation7,8. Furthermore the higher etching rate of H atoms for non-diamond carbon9 is suspected to lead to the formation of thermodynamic metastable diamond as the only phase10. At last H atoms bonded to carbon on the surface may stabilize the sp3-bonds necessary for diamond formation11.


Filament Surface Filament Temperature Filament Diameter High Etching Rate Hydrogen Dissociation 


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  1. 1.
    R. C. DeVries, Ann. Rev. Mater. Sci. 17, 161 (1987)CrossRefGoogle Scholar
  2. 2.
    K. E. Spear, J. Am. Ceram. Soc. 72, 171 (1989)CrossRefGoogle Scholar
  3. 3.
    M. Kamo, Y. Sato, S. Matsumoto, and N. Setaka, J. Cryst. Growth 62, 642 (1983)ADSCrossRefGoogle Scholar
  4. 4.
    S. Matsumoto, Y. Sato, M. Kamo, and N. Setaka, Jpn. J. Appl. Phys. 21, L183 (1982)ADSCrossRefGoogle Scholar
  5. 5.
    K. Kurihara, K. Sasaki, M. Kawarada, and N. Koshino, Appl. Phys. Lett. 52, 437 (1988)ADSCrossRefGoogle Scholar
  6. 6.
    L. M. Hanssen, W. A. Carrington, and J. E. Snail, Materials Letters 7, 289 (1989)CrossRefGoogle Scholar
  7. 7.
    M. Tsuda, M. Nakajiama, and S. Oikawa, J. Am. Chem. Soc. 108, 5780 (1986)CrossRefGoogle Scholar
  8. 8.
    D. Huang, M. Frenklach, and M. Maroncelli, J. Phys. Chem. 92, 6379 (1988)CrossRefGoogle Scholar
  9. 9.
    N. Setaka, J. Mater. Res. 4, 664 (1989)ADSCrossRefGoogle Scholar
  10. 10.
    B. V. Spitsyn, L. L. Bouilov, B. V. Derjaguin, J. Cryst. Growth 52, 219 (1981)ADSCrossRefGoogle Scholar
  11. 11.
    F. G. Celii and J. E. Butler, Appl. Phys. Lett. 54, 1031 (1989)ADSCrossRefGoogle Scholar
  12. 12.
    U. Meier, K. Kohse-Höinghaus and Th. Just, Chem. Phys. Letters 126, 567 (1986)ADSCrossRefGoogle Scholar
  13. 13.
    U. Meier, K. Kohse-Höinghaus, L. Schäfer, and C.-P. Klages, submitted to Applied OpticsGoogle Scholar
  14. 14.
    J. Bittner, K. Kohse-Höinghaus, U. Meier, S. Kelm and Th. Just, Combustion and Flame 71, 41 (1988)CrossRefGoogle Scholar
  15. 15.
    K. B. Blodgett and I. Langmuir, Phys. Rev. 40, 78 (1932) and references thereinADSCrossRefGoogle Scholar
  16. 16.
    R. Duff and S. H. Bauer, J. Chem. Phys. 36, 1754 (1962)ADSCrossRefGoogle Scholar
  17. 17.
    J. Crank, The Mathematics of Diffusion, Oxford University Press (1956)Google Scholar
  18. 18.
    B. Stevanov and L. Zarkova, J. Phys. D: Appl. Phys. 9, 1217–1976Google Scholar
  19. 19.
    E. Schnedler, Philips J. Res. 38, 224 (1983)Google Scholar
  20. 20.
    G. Dittmer, personal communicationGoogle Scholar
  21. 21.
    R. B.Bird, W. E. Steward, and E. N. Lightfood, Transport Phenomena, John Wiley li Sons (1960)Google Scholar
  22. 22.
    J. Warnatz in Combustion Chemistry, W. C. Gardiner, Jr. (Ed), Springer-Verlag (1984)Google Scholar
  23. 23.
    E. J. Covington, Illuminating Engineering 63, 134 (1968)Google Scholar
  24. 24.
    F. Jansen, I. Chen, and M. A. Machonkin, J. Appl. Phys. 66 5749 (1989)ADSCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1991

Authors and Affiliations

  • L. Schäfer
    • 1
  • U. Bringmann
    • 1
  • C.-P. Klages
    • 1
  • U. Meier
    • 1
  • K. Kohse-Höinghaus
    • 1
  1. 1.Philips GmbH Forschungslaboratorium HamburgHamburgGermany

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