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Mechanical Properties of Low Dielectric-Constant Organic-Inorganic Hybrids

Published online by Cambridge University Press:  10 February 2011

Robert F. Cook*
Affiliation:
Department of Chemical Engineering and Materials Science University of Minnesota, Minneapolis, MN 55455
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Abstract

Spin-on glasses, generated by the condensation of an organic-inorganic hybrid silsesquioxane (SSQ), have great potential as low dielectric-constant semiconductor interconnection materials. After curing and condensation SSQ materials consist of an amorphous, inorganic, –Si–O-Sibridging network with organic, non-bridging –Si–R side groups. Relative dielectric constants in the range 2.5–3.3 are obtained for SSQ materials, depending on the curing conditions, and compare with 4.0 for conventionally-used fused silica. The non-bridging side groups significantly disrupt the SSQ network—occupying more than 25% of the Si bonds—and lead to materials that are considerably less stiff, hard and tough than fused silica. Perhaps more importantly, SSQ materials have thermal expansion coefficients greater than that of the intended Si substrate and therefore finish curing in a state of residual tension, leading to a susceptibility to stress-corrosion cracking. In this paper the development of thermomechanical properties during curing of SSQ spin-on glasses is considered and related to the driving force for film cracking deriving from the residual tension. Various crack suppression schemes involving mechanisms both intrinsic and extrinsic to the base SSQ are discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1. Lee, W. W. and Ho, P. S., MRS Bulletin 22, p. 19 (1997).10.1557/S0883769400034151Google Scholar
2. The National Technology Roadmap for Semiconductors, Semiconductor Industry Association (1997) 99117.Google Scholar
3. Cook, R. F., Liniger, E. G., Klaus, D. P., Simonyi, E. E. and Cohen, S. A., in Low-Dielectric Constant Materials 1V, ed. Chiang, C., Ho, P. S., Lu, T.-M. and Wetzel, J. T., MRS Symposium Proceedings, Vol. 511, (1998), 3338.Google Scholar
4. Baney, R. H., Itoh, M., Sakakibara, A. and Suzuki, T., Chem. Rev. 95, p. 1409 (1995).10.1021/cr00037a012Google Scholar
5. Petkov, M. P., Weber, M. H., Lynn, K. G., Rodbell, K. P. and Cohen, S. A., Appl. Phys. Letters 74 (1999) 21462148.10.1063/1.123815Google Scholar
6. Cook, R. F. and Liniger, E. G., in Low-Dielectric Constant Materials IV, ed. Chiang, C., Ho, P. S., Lu, T.-M. and Wetzel, J. T., MRS Symposium Proceedings, Vol. 511, (1998), 171176.Google Scholar
7. Cook, R. F. and Liniger, E. G., in Dielectric Material Integration for Microelectronics, ed. Brown, W. D., Ang, S. S., Loboda, M., Sammakia, B., Singh, R. and Rathore, H. S.. Electrochemical Society (1998) pp. 129148.Google Scholar
8. Miller, R. D., Hedrick, J. L., Yoon, D. Y., Cook, R. F., and Hummel, J. P., MRS Bulletin, 22 (1997) 4448.10.1557/S0883769400034199Google Scholar
9. Thouless, M. D., J, Vac. Sci. Technol. A 9, p. 2510 (1991).10.1116/1.577265Google Scholar
10. Cook, R. F., Mater. Sci. Eng. A, 260 (1999) 2940.10.1016/S0921-5093(98)00980-0Google Scholar
11. Ho, S. and Suo, Z., J Appl. Mech. 60 (1993) 890894 10.1115/1.2900998Google Scholar