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Porous Silica: A Potential Material for Low Dielectric Constant Applications

Published online by Cambridge University Press:  10 February 2011

Edward D. Birdsell  and
Rosario A. Gerhardt
Edward D. Birdsell
Affiliation:
Georgia Institute of Technology, School of Material Science and Engineering, Atlanta, GA
Rosario A. Gerhardt
Affiliation:
Georgia Institute of Technology, School of Material Science and Engineering, Atlanta, GA
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Abstract

Highly porous (15% dense) silica thin films with k < 2.2 have been produced using a colloidal sol-gel process. This process uses relatively inexpensive, commercially available colloidal silica and potassium silicate. These films were deposited by spin coating. The parameters for spin coating (spin speed, gelation time, gel composition, etc.) have been optimized and coherent films with thicknesses ranging from 0.7–2.0 μm can be reproducibly fabricated. Preliminary work shows that the porosity of these films ranges from a few rn to < 1 μm. The dielectric properties were examined for frequencies up to 1 MHz. Compatibility of the films with IC processing was also investigated.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 511: Symposium E – Low Dielectric Constant Materials IV , 1998 , 111
Copyright
Copyright © Materials Research Society 1998

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References

REFERENCES

1 –The National Technology Roadmap for Semiconductors, Semiconductor Industry Association, 1997 Google Scholar
2 – Shoup, R. D., “Controlled Pore Silica Bodies Gelled from Silica Sol-Alkali Silicate Mixtures”, Colloid and Interface Science, Vol.3: 63–69, 1976 Google Scholar
3 – Cao, W., Gerhardt, R. and Wachtman, J. B. Jr, “Low Permitivity Porous Silica by a Colloidal Processing Method”, Ceramic Substrates and Packages For Electronics Applications, Advances in Ceramics, Vol.26: 409–418 (1989)Google Scholar
4 – Kerch, H. M., Gerhardt, R., Grazul, J., “Quantitative Electron Microscopic Investigation of the pore structure in 10:90 Colloidal Silica-Potassium Silicate Sol-Gels”, Journal of the American Ceramic Society 73[8] 2228–2237 (1990)Google Scholar
5 – Kerch, H. M., Cosandey, F. and Gerhardt, R., “Imaging of Fine Porosity in Colloidal Silica: Alkali Silicate Gels by a Defocus Contrast Technique”, J. Non-Cryst. Solids 152, 18–31 (1993)Google Scholar
6 – Kokan, J. R., Tadayon, F., Gerhardt, R..A., Kohl, P. A., “Sol-Gel Processing of Porous Silica Thin Films for Interlevel Dielectrics in Integrated Circuits,” IEEE Proc. 44th Annual Electron Components and Technology Conference, pp. 704–711 (1994)Google Scholar
7 – Gerhardt, R. A., Kokan, J. R., Kohl, P. A., “Low Permittivity Porous Silica Thin Films for MCM-C/D Applications”, Advances in Ceramics Multi-Chip Module (MCM) and High Performance Electronic Materials, pp. 209–219 (1994)Google Scholar
8 – Cao, W., Gerhardt, R., Wachtman, J. B. Jr, “Effects of Sodium Ions on the Dielectric Conductivity of Porous Silica in Humid Environments”, Physical Phenomena in Granular Materials, Mat. Res. Soc. Symp. Proc. Vol.195: 471–476 (1990)Google Scholar
9 – Meyers, K. S., Zhang, G., Gerhardt, R. A., “Dielectric Properties Dependence on Sodium and Potassium Content in Silica Xerogels”, Electrically Based Microstructural Characterization, Mat. Res. Soc. Symp. Proc. Vol.411, 217–222 (1996)Google Scholar
10 – Kokan, J. R., Gerhardt, R., “Humidity Effects on Porous Silica Thin Films”, Electrically Based Microstructural Characterization, Mat. Res. Soc. Symp. Proc. Vol. 411, 419–424 (1996)Google Scholar