IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Thin Films Friday Sessions
       Session TF-FrM

Paper TF-FrM6
Investigation of Nitrogen Bonding in Amorphous Carbon Nitride

Friday, November 2, 2001, 10:00 am, Room 123

Session: Diamond and Related Materials
Presenter: W.J. Gammon, College of William & Mary
Authors: W.J. Gammon, College of William & Mary
O. Kraft, Max-Planck-Institut für Metallforschung, Germany
R.L. Vold, College of William & Mary
G. Houtson, College of William & Mary
A.S. Reilly, College of William & Mary
B.C. Holloway, College of William & Mary
Correspondent: Click to Email
Previous x-ray photoelectron spectroscopy (XPS) work has shown that the N(1s) spectra of highly elastic amorphous carbon nitride (CN@sub x@) can be resolved into two peaks positioned at ~ 398.5 and 401 eV.@footnote 1@ Furthermore, the exact location and intensity of the two peaks is directly correlated to the mechanical properties of the film.@footnote 2@ Based on XPS data and theoretical calculations, earlier work suggests that the N(1s) peak at 398.5 eV in hard and elastic CN@sub x@, is due to nitrogen bonded to sp@super 3@ hybridized carbon.@footnote 2@ @super -@ @footnote 3@ This interpretation supports the phenomenological model that the mechanical properties of hard CN@sub x@ are due to the cross-linking of graphitic planes through sp@super 3@ bonded carbon.@footnote 2@ However, we present XPS data that suggest the low binding energy N(1s) peak may be due to sp@super 2@ coordinated nitrogen to carbon in an aromatic ring. Also, our data show that the N(1s) peak exhibits bonding over the whole range of possible hybridization. In fact, XPS is not sensitive enough to make unambiguous peak assignments in CN@sub x@, and XPS exhibits no resolvable chemical shift between sp@super 2@ and sp@super 3@ bonded carbon to carbon. However, nuclear magnetic resonance spectroscopy (NMR) provides better discrimination to these bonding types. Therefore, the purpose of this study is to clarify the dependence of chemical bonding on mechanical properties by using NMR data to remove the ambiguity of proposed XPS peak assignments. In this work, we present @super 13@C and @super 15@N NMR, XPS, and FTIR data on CN@sub x@. These films were deposited on a heated Si(001) substrate by DC magnetron sputtering, and nanoindentation was used to quantify the mechanical properties. NMR results are shown for both the hard and elastic phase (deposited at temperatures > 300 @super o@ C) and mechanically poor phase (deposited at ambient temperature). In addition, computational models will be developed concurrently from experimental data to investigate the stability of carbon/nitrogen structures. @FootnoteText@ @footnote 1@ B.C. Holloway, O. Kraft, D.K. Shuh, M.A. Kelley, W.D. Nix, P. Pianetta, and S. Hagström, Appl. Phys. Lett., 74, 3290 (1999). @footnote 2@ N. Hellgren, M.P. Johansson, E. Broitman, L. Hultman, and J. Sundren, Phys. Rev. B, 59, 5162, (1999). @footnote 3@ Å. Johansson and S. Stafström, J. Che. Phys., 111, 3203, (1999).