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Mechanical Characterization of Multilayer Thin Film Stacks Containing Porous Silica Using Nanoindentation and the Finite Element Method

Published online by Cambridge University Press:  01 February 2011

Ke Li
Affiliation:
Department of Civil Engineering
Subrahmanya Mudhivarthi
Affiliation:
Department of Civil Engineering Department of Mechanical Engineering
Sunil Saigal
Affiliation:
Department of Civil Engineering
Ashok Kumar
Affiliation:
Department of Mechanical Engineering Nanomaterials and Nanomanufacturing Research Center, University of South Florida, Tampa, FL 33613, U.S.A.
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Abstract

Novel metal/dielectric material combinations are becoming increasingly important for reducing the resistance-capacitance (RC) interconnection delay within integrated circuits (ICs) as the device dimensions shrink to the sub-micron scale. Copper (Cu) is the material of choice for metal interconnects and SiO2 (with a dielectric constant k = ∼ 3.9) has been used as an interlevel dielectric material in the industry. To meet the demands of the international road map for semiconductors, materials with a significantly lower dielectric constant are needed. In this study, the effects of porosity and layer thicknesses on the mechanical properties of a multilayer thin film (Cu, Ta and SiO2)-substrate (Si) system are examined using nanoindentation and finite element (FE) simulations. A micromechanics model is first developed to predict the stress-strain relation of the porous silica based on the homogenization method for composite materials. An FE model is then generated and validated to perform a parametric study on nanoindentation of the Cu/Ta/SiO2/Si system aiming to predict the mechanical properties of the multilayer film stack.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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References

1. Maex, K., Baklanov, M. R., Shamiryan, D., Iacopi, F., Brongersma, S. H., Yanovitskaya, Z. S., J. Appl. Phys. 93, 8793 (2003).Google Scholar
2. Oliver, W. C., Pharr, G. M., MRS Bull. 17, 2833 (1992).Google Scholar
3. Iskandar, F., Abdullah, M., Yoden, H., Okuyama, K., J. Appl. Phys. 93, 9237 (2003).Google Scholar
4. Knapp, J. A., Follstaedt, D. M., Myers, S. M., Barbour, J. C., Friedmann, T. A., J. Appl. Phys. 85, 1460 (1999).Google Scholar
5. Iacopi, F., Brongersma, S. H., Vandevelde, B., O'Toole, M., Degryse, D., Travaly, Y., Maex, K., Microelectron. Eng. 75, 54 (2004).Google Scholar
6. Li, K., Gao, X.-L., Subhash, G., Int. J. Solids Struct. 42, 1777 (2005).Google Scholar
7. Vena, P., Gastaldi, D., Compos.: Part B 36, 115 (2005).Google Scholar
8. Pelletier, H., Krier, J., Cornet, A., Mille, P., Thin Solid Films 379, 147 (2000).Google Scholar
9. National Materials Advisory Board, Coatings for high-temperature structural materials: trends and opportunities (The National Academy of Sciences, 1996), p. 18.Google Scholar
10. Boyer, H. E., Atlas of Stress-Strain Curves (ASM, Metals Park, OH, 1987).Google Scholar
11. Bhattacharya, A. K., Nix, W. D., Int. J. Solids Struct. 24, 1287 (1988).Google Scholar
12. Volinsky, A. A., Gerberich, W. W., Microelectron. Eng. 69, 519 (2003).Google Scholar