Theoretical and Experimental Investigation of Ultrathin Oxynitrides


Microscopic properties of thin oxynitrides are investigated using a combination of the infrared ATR and ab-initio electronic structure methods. We use a theoretical structural model based on the Si-SiO2 interface with the oxide thickness of 0.8 nm. The interfacial region amounts to about 0.4 nm (the total thickness of the oxygen containing layer is 1.2 nm). The Quantum Molecular Dynamics simulations suggest that Ν accumulates at the interface. We have generated samples with the nitrogen concentrations from 1.69 × 1014 cm−2 to 6.78 × 1014 cm−2. The structural analysis of nitrogen containing cells indicates a significant improvement of the oxide layer and the strain reduction at the interface. We have performed a calculation of the vibrational density of states. A N-localized mode at 809 cm-1 has been identified. The experimental ifnrared ATR data is in qualitative agreement with the calculation. The valence band offset calculations reveal a 0.3 eV increase of the offset due to nitrogen at the highest nitrogen concentration considered. The valence band offset increase comes mainly from the structural change in the oxide layer. The interfacial dipole contributes 0.12 eV to the increase, while the structural change in the oxide layer gives additional 0.2 eV.

This is a preview of subscription content, access via your institution.


  1. 1.

    R. I. Hegde, B. Maiti, and P.J. Tobin, J. Electrochem. Soc. 144, 1081 (1997)

    CAS  Article  Google Scholar 

  2. 2.

    Y. Wu, H. Niimi, H. Yang, G. Lucovsky, and R.B. Fair, J. Vac. Sci. Technol. B 17, 1813 (1999).

    CAS  Article  Google Scholar 

  3. 3.

    G. Lucovsky, H. Niimi, Y. Wu, C.R. Parker, and J.R. Hauser, J. Vac. Sci. Technol. B 16, 1721 (1998).

    CAS  Article  Google Scholar 

  4. 4.

    J.C. Phillips, J. Vac. Sci. Technol. B 17, 1803 (1998).

    Article  Google Scholar 

  5. 5.

    G. Lucovsky, Y. Wu, H. Niimi, V. Misra, and J.C. Philips, Appl. Phys. Lett. 74, 2005 (1999).

    CAS  Article  Google Scholar 

  6. 6.

    A.A. Demkov and O.F. Sankey, Phys. Rev. Lett. 83, 2038 (1999).

    CAS  Article  Google Scholar 

  7. 7.

    A. A. Demkov, J. Ortega, O. F. Sankey, and M. Grumbach, Phys Rev. B 52, 1618 (1995).

    CAS  Article  Google Scholar 

  8. 8.

    O. F. Sankey, A. A. Demkov, W. Windl, J. H. Fritsch, J. P. Lewis, M. Fuentes-Cabrera, Int. J. Quant. Chem. 69, 327 (1998).

    CAS  Article  Google Scholar 

  9. 9.

    E.P. Gusev, H.-C. Lu, E.L. Garfunkel, T. Gustafson, M.L. Green, IBM J. Res. Develop. 43, 265 (1999).

    CAS  Article  Google Scholar 

  10. 10.

    R. Grun, Acta Cryst. B 35, 800 (1979).

    Article  Google Scholar 

  11. 11.

    J. Liang, L. Topor, and A. Navrotsky, J. Mater. Res. 14, 1 (1999).

    Article  Google Scholar 

  12. 12.

    S.R. Srinivasa, L. Cartz, J.D. Joergensen, T.G. Worlton, R.A. Beyerlein, and M. Billy. J. Appl. Cryst. 10, 167 (1977).

    Article  Google Scholar 

  13. 13.

    G.L. Zhao, and M.E. Bachlencher, Phys. Rev. B 58, 1887 (1998).

    CAS  Article  Google Scholar 

Download references


The authors wish to thank Anatoli Korkin, Vernon Cole, Phil Tobin, and Gerry Lucovsky for helpful discussions, and Rama Hegde for providing the samples for this study.

Author information



Corresponding author

Correspondence to A. A. Demkov.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Demkov, A.A., Liu, R. Theoretical and Experimental Investigation of Ultrathin Oxynitrides. MRS Online Proceedings Library 592, 18–23 (1999).

Download citation