Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-29T09:24:57.288Z Has data issue: false hasContentIssue false

Strength-porosity relationship of nanoporous MSSQ films characterised by Brillouin Light Scattering and Surface Acoustic Wave Spectroscopy

Published online by Cambridge University Press:  01 February 2011

C.M. Flannery
Affiliation:
Paul-Drude-Institut für Festkörperelektronik, Hausvogteiplatz 5-7, D-10117 Berlin, Germany currently at National Institute of Standards & Technology, 325 Broadway, Boulder CO, USA
T. Wittkowski
Affiliation:
Fachbereich Physik, Universität Kaiserslautern, Erwin Schrödinger Str. 56, D-67663 Germany
K. Jung
Affiliation:
Fachbereich Physik, Universität Kaiserslautern, Erwin Schrödinger Str. 56, D-67663 Germany
B. Hillebrands
Affiliation:
Fachbereich Physik, Universität Kaiserslautern, Erwin Schrödinger Str. 56, D-67663 Germany
M.R. Baklanov
Affiliation:
XPEQT at IMEC, Leuven, B-3001, Belgium
Get access

Abstract

Nanoporous Methylsilsesquioxane films are a leading candidate for low dielectric constant (low-κ) materials for microelectronic interconnect. Mechanical strength reduces rapidly with lower κ (increasing porosity) however, and there is a lack of techniques to characterize these properties in the κ∼2 range. This work reports application of surface acoustic wave spectroscopy and Brillouin light scattering to characterization of density/porosity and Young's modulus values of a range of Methylsilsesquioxane films from different manufacturers. We show that the results are validated by independent measurements and that nanoindentation measurements consistently overestimate stiffness. The behaviour of 3 sets of films show different stiffness-porosity relationships, the initially stiffer materials declining more rapidly with increasing porosity than the softer materials. This has important consequences for stiffness properties in the κ<2 region.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

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. Jin, C., Luttmer, J.D., Smith, D.M., Ramos, T.A., MRS Bull. 22 (10) 39 (1997).Google Scholar
2. Hawker, C.J., Hedrick, J.L., Miller, R.D., Volksen, W., MRS Bull. 25 (4), 54 (2000).Google Scholar
3. Baklanov, M.R., Jehoul, C., Flannery, C.M. et al, Proc. 2001 MRS Advanced Metallisation Conference (AMC), Montreal, Canada.Google Scholar
4. Kuschnereit, R., Fath, H., Kolomenskii, A.A., Szabadi, M., Hess, P., Appl. Phys. A 61, 269 (1995).Google Scholar
5. Flannery, C.M., Murray, C., Streiter, I., Schulz, S.E., Thin Solid Films 588, 14 (2001).Google Scholar
6. Hillebrands, B., Rev. Sci. Instrum. 70, 1589 (1999).Google Scholar
7. Baklanov, M.R., Mogilnikov, K.P., Polovinkin, V.G. and Dultsev, F.N., J. Vac. Sci. Technol. B 18, 1385 (2000).Google Scholar
8. Wu, W.-L., Wallace, W. E., Lin, E.K., Lynn, G.W., Glinka, C.J., Ryan, E.T., Ho, H.-M., J. Appl. Phys., 87, 1193 (2000).Google Scholar
9. Hay, J.L. and Pharr, G.M., in ASM Handbook Vol. 8: Mechanical Testing and Evaluation, ed. Kuhn, H. and Medlin, D., (ASM International, 2000), pp. 232243.Google Scholar
10. Nelsen, D., Gostein, M., Maznev, A.A., Proc. 9th. Symp. on Polymers for Microelectronics, Wilmington, Delaware, May 2000.Google Scholar
11. Flannery, C.M., Murray, C., Streiter, I., Schulz, S.E., Baklanov, M.R., MRS Proc. 672, 2001.Google Scholar
12. VanLandingham, M.R., Villarrubia, J.S., Guthrie, W.F., Meyers, G.F., Macromolecular Symposia, 167, 1544 (2001).Google Scholar