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Aqueous solution diffusion in hydrophobic nanoporous thin-film glasses

  • Eric P. Guyer (a1), Jay Gantz (a1) and Reinhold H. Dauskardt (a1)


We demonstrate that diffusion of aqueous buffered solutions into strongly hydrophobic nanoporous methyl silsesquioxane glass films can occur without the application of external pressure. The organic component of these glasses in the form of methyl groups imparts the strong hydrophobicity and perception that they are impervious to the ingress of aqueous solutions by capillary action or diffusion. The presence of small concentrations of organic buffering agents in buffered solutions appears to facilitate the diffusion. The diffusion distance followed a square root of time dependence characteristic of Fick’s Law. The diffusion coefficients varied markedly with the concentration of buffering agents, solution pH, and temperature. Similar effects were not observed for nonbuffered solutions that exhibited no detectable diffusion. Likely mechanisms responsible for the observed behavior are proposed.


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1Kresge, C.T., Leonowicz, M.E., Roth, W.J., Vartuli, J.C., and Beck, J.S.: Ordered mesoporous molecular-sieves synthesized by a liquid-crystal template mechanism. Nature 359, 710 (1992).
2Hedrick, J.L., Miller, R.D., Hawker, C.J., Carter, K.R., Volksen, W., Yoon, D.Y., and Trollsas, M.: Templating nanoporosity in thin-film dielectric insulators. Adv. Mater. 10, 1049 (1998).
3Zhao, D.Y., Feng, J.L., Huo, Q.S., Melosh, N., Fredrickson, G.H., Chmelka, B.F., and Stucky, G.D.: Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 angstrom pores. Science 279, 548 (1998).
4Guarini, K.W., Black, C.T., Milkove, K.R., and Sandstrom, R.L.: Nanoscale patterning using self-assembled polymers for semiconductor applications. J. Vac. Sci. Technol., B 19, 2784 (2001).
5Yang, S., Mirau, P.A., Pai, C-S., Nalamasu, O., Reichmanis, E., Lin, E.K., Lee, H-J., Gidley, D.W., and Sun, J.: Molecular templating of nanoporous ultralow-dielectric constant (approximately = 1.5) organosilicates by tailoring the microphase separation of triblock copolymers. Chem. Mater. 13, 2762 (2001).
6Shaw, T.M., Jimerson, D., Haders, D., Murray, C.E., Grill, A., Edelstein, D.C., and Chidambarrao, D.: Moisture and oxygen uptake in low k/copper interconnect structures, in Advanced Metallization Conference 2003 (AMC 2003), Montreal, Quebec, Canada, & Tokyo, Japan (Materials Research Society, Warrendale, PA, 2004).
7Worsley, M.A., Bent, S.F., Gates, S.M., Shaw, T., Volksen, W., and Miller, R.D.: Detection of open or closed porosity in low-k dielectrics by solvent diffusion. Microelectron. Eng. 82, 113 (2005).
8Shamiryan, D., Abell, T., Le, Q.T., and Maex, K.: Pinhole density measurements of barriers deposited on low-k films. Microelectron. Eng. 70, 341 (2003).
9Shamiryan, D., Baklanov, M.R., and Maex, K.: Diffusion barrier integrity evaluation by ellipsometric porosimetry. J. Vac. Sci. Technol., B Microelectronics and Nanometer Structures. 21(1 SPEC.), 220 (2003).
10Shamiryan, D. and Maex, K.: Solvent diffusion in porous low-k dielectric films, in Materials, Technology and Reliability for Advanced Interconnects and Low-k Dielectrics–2003, edited by McKerrow, A.J., Leu, J., Kraft, O. and Kikkawa, T. (Mater. Res. Soc. Symp Proc. 766, Warrendale, PA, 2003), p. 229.
11Kim, H.C., Wilds, J.B., Hinsberg, W.D., Johnson, L.R., Volksen, W., Magbitang, T., Lee, V.Y., Hedrick, J.L., Hawker, C.J., Miller, R.D., and Huang, E.: Selective sorption of nanoporous poly(methyl silsesquioxane). Chem. Mater. 14, 4628 (2002).
12Guyer, E.P., Patz, M., and Dauskardt, R.H.: Fracture of nanoporous methylsilsesquioxane thin-film glasses. J. Mater. Res. 21, 882 (2006).
13Petty, M.C.: Langmuir-Blodgett Films: An Introduction (Cambridge University Press, Cambridge, UK, 1996), pp. 1238.
14Lefevre, B., Saugey, A., Barrat, J.L., Bocquet, L., Charlaix, E., Gobin, P.F., and Vigier, G.: Intrusion and extrusion of water in hydrophobic mesopores. J. Chem. Phys. 120(10), 4927 (2004).
15Spuller, M.T. and Hess, D.W.: Incomplete wetting of nanoscale thin-film structures. J. Electrochem. Soc. 150, G476 (2003).
16Le, Q., Jeannot, V., Baklanov, M., Vanderheyden, R., Boullart, W., and Vanhaelemeersch, S.: Effect of surfactant as additive in wet clean solutions on properties of low-k materials. Electrochem. Solid-State Lett. 9, F17 (2006).
17Thomson, W.: On the equilibrium of vapor at a curved surface of liquid. Philos. Mag. 42, 448 (1871).
18Fisher, L.R., Gamble, R.A., and Middlehurst, J.: The Kelvin equation and the capillary condensation of water. Nature 290, 575 (1981).


Aqueous solution diffusion in hydrophobic nanoporous thin-film glasses

  • Eric P. Guyer (a1), Jay Gantz (a1) and Reinhold H. Dauskardt (a1)


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