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Thermally induced hillock formation in Al–Cu films

Published online by Cambridge University Press:  31 January 2011

C. Y. Chang
Affiliation:
Laboratory for Solid State Science and Technology, Physics Department, Syracuse University, Syracuse, New York 13244–1130
R. W. Vook
Affiliation:
Laboratory for Solid State Science and Technology, Physics Department, Syracuse University, Syracuse, New York 13244–1130
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Abstract

Isothermal annealing studies of hillocks formed on Al–15 wt.% Cu films, vapor deposited at 25 °C on oxidized silicon wafers, were carried out in situ in a scanning electron microscope. The original hillocks formed as a result of substrate-induced thermal expansion strains which caused material to diffuse out of the film to form the hillocks when the films were heated to the isothermal annealing temperatures. During isothermal annealing the hillock density decreased and the average size of the hillocks increased. Measurements of these quantities as a function of time were made at a series of temperatures ranging from 200 to 300 °C. The activation energies for these two cases were found to be 0.29 and 0.28 eV, respectively. X-ray energy spectroscopy analysis of the films showed that the hillocks were richer in copper than the matrix. Transmission electron microscopy showed that the average hillock and grain sizes in the variously annealed films were linearly related and of the same order of magnitude. The results were also analyzed using Chakraverty's models for surface and interfacial diffusion. It was concluded that the evidence clearly shows that the observed processes could be well characterized by a typical Ostwald ripening model.

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Articles
Copyright
Copyright © Materials Research Society 1989

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References

REFERENCES

1Breitling, H.M. and Hummel, R. E., J. Phys. Chem. Solids 33, 845 (1972).CrossRefGoogle Scholar
2Heurle, F. M. and Ho, P. S., in Thin Films: Interdiffusion and Reactions, edited by Poate, J., Tu, K. N., and Mayer, J. (1978), p. 244.Google Scholar
3Robert, S. and Dobson, P. J., Thin Solid Films 135, 137 (1986).CrossRefGoogle Scholar
4Herman, D. S., Schuster, M. A., and Gerber, R. M., J. Vac. Sci. Tech. 9, 515 (1971).Google Scholar
5Santoro, C.J., J. Electrochem. Soc. 116, 361 (1969).CrossRefGoogle Scholar
6d'Heurle, F., Berenbaum, L., and Rosenberg, R., Trans. Metall. Soc. AIME 242, 502 (1968).Google Scholar
7Sharma, S.K., Rao, S.U.M., and Kumar, Narendra, Thin Solid Films 142, L95 (1986).CrossRefGoogle Scholar
8Sharma, S.K. and Spitz, J., Thin Solid Films 65, 339 (1980).CrossRefGoogle Scholar
9Presland, A.E.B., Price, G. L., and Trimm, D.L., Surface Science 29, 424 (1972).CrossRefGoogle Scholar
10Vook, R. W. and Witt, F., J. Appl. Phys. 36, 2169 (1965).Google Scholar
11Witt, F. and Vook, R. W., J. Appl. Phys. 39, 2773 (1968).CrossRefGoogle Scholar
12Philofsky, E., Ravi, K., Hall, E., and Black, J., in IEEE 9th Conference on Reliability Physics (1971), p. 120.Google Scholar
13Chaudhari, P., IBM J. Res. Develop. 13, 197 (1969).CrossRefGoogle Scholar
14Chakraverty, B. K., J. Phys. Chem. Solids 28, 2401 (1967).Google Scholar
15Hirth, J.P., J. Crystal Growth 17, 63 (1972).Google Scholar
16Ghandhi, S. K., VLSI Fabrication Principles (John Wiley and Sons Inc., New York, 1983), p. 387.Google Scholar
17Colby, J. W., MAGIC IV – A Computer Program for Quantitative Electron Microprobe Analysis (1971).Google Scholar
18Agarwala, B.N., Patnaik, B., and Schnitzel, R., J. Appl. Phys. 43, 1487 (1972).CrossRefGoogle Scholar
19Towner, J. M., Solid State Tech. October, 197 (1984).Google Scholar
20Rossnagel, S.M. and Robinson, R.S., J. Vac. Sci. Technol. 20, 195 (1982).CrossRefGoogle Scholar
21Schreiber, H. U., Solid-State Electron. 24, 583 (1981).Google Scholar
22Gol'diner, M.G., Sov. Phys. Solid State 17, 1234 (1975).Google Scholar
23Kang, S. K. and Laird, C., Acta Metall. 23, 35 (1975).Google Scholar
24Sacedon, J. L. and Martin, C. S., Thin Solid Films 10, 99 (1972).Google Scholar
25Gleiter, H., in Physical Metallurgy, 3rd ed., edited by Cahn, R. W. and Haasen, P. (1983), p. 684.Google Scholar