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Solvent diffusion in porous low-k dielectric films

Published online by Cambridge University Press:  01 February 2011

Denis Shamiryan
Affiliation:
IMEC, Kapeldreef 75, Leuven, 3001, Belgium, also at Electrical Engineering department of K.U.Leuven
Karen Maex
Affiliation:
IMEC, Kapeldreef 75, Leuven, 3001, Belgium, also at Electrical Engineering department of K.U.Leuven
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Abstract

Porous materials are being investigated as low dielectric constant (low-k) materials. While porosity decreases the k-value of a material by decreasing its density, it simultaneously allows unwanted adsorption and diffusion of chemicals inside the porous matrix. To investigate this, different porous low-k materials, specifically silicon oxycarbide (SiOCH), methylsilsesquioxane (MSQ), and a polymer, were exposed to polar (ethanol) and non-polar (toluene) solvents. A difference in diffusion of polar and non-polar solvents would be an indication of the density of polar centers which attract polar molecules (such as water) and increase the dielectric constant of a film. The diffusion coefficient for toluene at room temperature was found to be approximately 2×10-5 cm2/sec for MSQ (40% porosity), 10-7 cm2/sec for SiOCH (7% porosity), 2×10-8 cm2/sec for the polymer. The observed diffusion can be described by a model of a viscous flow in a porous medium. The toluene/ethanol diffusion coefficient ratios were 4.4, 1.3, 1 for MSQ, SiOCH, and the polymer, respectively. The difference in toluene/ethanol diffusion can potentially be used to screen a material's affinity for water adsorption.

Type
Research Article
Copyright
Copyright © Materials Research Society 2003

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References

1. Maex, K., Baklanov, M. R., Shamiryan, D., Iacopi, F., Brongersma, S. H., and Yanovitskaya, Z. S., J. Appl. Phys. 93, (2003) (in press).Google Scholar
2. Snyder, L. R. and Kirkland, J. J.. Introduction to modern liquid chromatography. 2-nd edition, (A Wiley-Interscience Publication, New York, 1979).Google Scholar
3. Snyder, L. R.. Principles of adsorption chromatography, (Dekker, New York, 1968).Google Scholar
4. Shamiryan, D., Baklanov, M. R., Vanhaelemeersch, S., and Maex, K., Electrochem. Sol. St. Lett. 4, F3 (2001).Google Scholar
5. Dultsev, F. N. and Baklanov, M. R., Electrochem. Sol. St. Lett. 2, 192 (1999).Google Scholar
6. Vereecke, G., Kondoh, E., Richardson, P., Maex, K., Heyns, M. M. and Nényei, Z.. IEEE Trans. Semicond. Manuf. 13, 315 (2000).Google Scholar
7. Atkins, P. W.. Physical Chemistry. 6th edition, (Oxford university press, 1998) p.753.Google Scholar
8. Rouquerol, J., Avnir, D., Fairbridge, C. W., Everett, D. H., Haynes, J. H., Pernicone, N., Ramsay, J. D. F., Sing, K. S. W. and Unger, K. K.. Pure & Appl. Chem. 66, 1739 (1994).Google Scholar
9. Do, D. D.. Adsorption analysis: equilibria and kinetics. Series on chemical engineering, vol.2, (Imperial College Press, London, 1998) p.374.Google Scholar
10.ibid ref. 9, p.398.Google Scholar