Hostname: page-component-848d4c4894-tn8tq Total loading time: 0 Render date: 2024-07-01T09:26:32.624Z Has data issue: false hasContentIssue false

Measurement of Elastic Modulus and Poisson's Ratio of Diamond–Like Carbon Films

Published online by Cambridge University Press:  10 February 2011

Kwang Yong Eun
Affiliation:
Thin Film Technology Research Center, Korea Institute of Science and Technology, P. O. Box 131, Cheongryang, Seoul, 130-650, Korea
Dae-Hong Ko
Affiliation:
Department of Ceramic Engineering, Yonsei University, Seoul, 120-701, Korea
Get access

Abstract

Elastic modulus and Poisson's ratio of diamond-like carbon (DLC) film was measured by a simple method using DLC bridges which are free from mechanical constraint of substrate. The DLC films were deposited on Si wafer by C6H6r.f. glow discharge at the deposition pressure 1.33 Pa. Because of the high residual compressive stress of the film, the bridge exhibited a sinusoidal displacement by removing the constraint of the substrate. By measuring the amplitude with known bridge length, we could determine the strain of the film required to adhere to the substrate. Combined with independent stress measurement by laser reflection method, this method allows calculation of the biaxial elastic modulus, E/(1–v), where E is the elastic modulus and v Poisson's ratio of the DLC film. By comparing the biaxial elastic modulus with plane-strain modulus, E/(1–v2), measured by nano-indentation, we could further determine the elastic modulus and Poisson's ratio, independently. The elastic modulus, E, increased from 87 to 133 GPa as the negative bias voltage increased from 400 to 550 V. Poisson's ratio was estimated to be about 0.20 in this bias voltage range. For the negative bias voltages less than 400 V, however, the present method resulted in negative Poisson's ratio which is physically impossible. The limitation of the present method was also discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Fujimori, N., New Diamond, 3, 20 (1989).Google Scholar
2 Imai, T., Nakahata, H. and Fujimori, N., U. S. Patent, 4,952,832 (1990).Google Scholar
3 Angus, J. C., Koidl, P. and Domitz, S., in Plasma Deposited Thin Films, edited by Mort, J. and Jansen, F. (CRC, Boca Raton, FL, 1986), p. 89.Google Scholar
4 Oliver, W. C. and Pharr, G. M., J. Mater. Res., 7, 1564 (1992).Google Scholar
5 Sandercook, J. R., in Light Scattering in Solids, edited by Cardona, M. and Giintherodt, G., Topics in Applied Physics Vol. 51 (Springer, Berlin, 1982), p. 173.Google Scholar
6 Scheider, D., Scheibe, H.J., Schwarz, T. and Hess, P., Diamond Relat. Mater., 2, 92 (1992).Google Scholar
7 Khakani, M. A. El, Chaker, M., Jean, A., Boily, S., Kieffer, J. C., O'Hern, M. E., Ravet, M. F. and Rousseaux, F., J. Mater. Res., 9, 96 (1994).Google Scholar
8 Berry, B. S., Pritchet, W. C., Cuomo, J. J., Guarnieri, C. R. and Whitehair, S. J., Appl. Phys. Lett., 57, 32 (1990).Google Scholar
9 Cho, S.J., Lee, K.R., Eun, K. Y., Hahn, J. H. and Ko, D.H., Thin Solid Films, in press (1998).Google Scholar
10 Cho, S.J., Lee, K.R., Eun, K. Y., Hahn, J. H. and Ko, D.H., presented at MRS Fall Meeting, Boston, MA (1997).Google Scholar
11 Brenner, A and Senderoff, S., J. Res. Natl. Bur. Stand., 42, 105 (1949).Google Scholar
12 Lee, K.R., Y.J. Balk and Eun, K. Y., Dia. Rel. Mater. 3, 1230 (1994).Google Scholar
13 Borden, P. G., Appl. Phys. Lett., 36, 829 (1980).Google Scholar
14 Howe, R. T. and Muller, R. S., J. Appl. Phys., 54 4674 (1983).Google Scholar
15 Jiang, X., K. Riechelt and Stritzker, B., J. Appl. Phys., 68, 1018 (1990).Google Scholar
16 Pivin, J. C., Thin Solid Films, 229, 83 (1993).Google Scholar