Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-27T12:55:31.539Z Has data issue: false hasContentIssue false

Kinetics of Cu Segregation in Al-Cu(1at% Cu) Interconnects Studied by Resistance Measurements

Published online by Cambridge University Press:  10 February 2011

A. J. Kalkman
Affiliation:
Delft Institute of Microelectronics and Submicron Technology, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
A. H. Verbruggen
Affiliation:
Delft Institute of Microelectronics and Submicron Technology, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
G. C. A. M. Janssen
Affiliation:
Delft Institute of Microelectronics and Submicron Technology, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
S. Radelaar
Affiliation:
Delft Institute of Microelectronics and Submicron Technology, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands.
Get access

Abstract

The time-dependence of the growth of Al2Cu precipitates in Al-Cu(lat% Cu) thin films is studied by means of resistance measurements at different temperatures. The samples are annealed at 400°C for 1 hour, and then quickly cooled down to room temperature. Afterwards, the samples are heated within one minute to a measurement temperature between 140 °C and 240 °C. Growth of precipitates causes a well defined decrease in resistance. The observed resistance decrease does not follow an exponential decay. In the investigated temperature range the resistance decrease can be accurately modelled by (R(t)-R∞) = (Ro-R∞)exp(-(t /τ)n), with the time constant τ= τ0 exp(Ea / kT). Excellent fits were obtained resulting in n = 0.66±0.05, independent of temperature, and Ea= 0.81±0.03 eV. This value for the activation energy agrees very well with the activation energy that has been reported in literature for both electromigration failure in Al-Cu and grain-boundary diffusion of Cu in Al. The value we found for n is intriguingly close to 2/3 and deviates strongly from the values of n reported for bulk Al-Cu (n = 1.5–1.8) in the same temperature range.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Ames, I., d'Heurle, F.M., Horstmann, R., IBM J. Res. Dev., 14, (1970) 461 Google Scholar
2. Hornbogen, E., Aluminum, 43 (1967) 41,Google Scholar
Murray, J.L., International Metals Reviews 1985, Vol. 3, No. 5, pp 211.Google Scholar
3. Kim, C. and Morris, J.W., J. Appl. Phys. 72 (1992) 1837,Google Scholar
Morris, J.W., Kim, C., Kang, S.H., Mat. Res. Soc. Symp. Proc. Vol 391, 1995, pp. 353.Google Scholar
4. Kim, C., Selitser, S.I., Morris, J.W., J. Appl. Phys., 75 (1994) 879.Google Scholar
5. Scorzoni, A., de Munari, I., Stulens, H., D'Haeger, V., Mat. Res. Soc. Symp. Proc. Vol. 391 1995, p 513.Google Scholar
6. Avrami, M., J. Chem. Phys. 7 (1940), 1103; 8 (1941) 212; 9 (1941) 177Google Scholar
7. Hu, C.K., Ho, P.S., and Small, M.B., J. Appl. Phys. 74 (1993) 969 Google Scholar
8. Guinier, A., Zeitschrift f. Electrochemie, 56 (1952) 468.Google Scholar
9. Hardy, H.K., J. Inst. Met., 79 (1951) 321.Google Scholar
10. Lankes, J.C., Wasserman, G., Zeitschrift f. Metallkunde, 41 (1950) 381 Google Scholar
11. Cottrell, A.H. and Bilby, B.A., Proc. Phys. Soc, 62 (1949) 4.Google Scholar
12. Harper, S., Phys. Rev., 83 (1951) 709.Google Scholar
13. Ham, F.S., J. Phys. Chem. Solids, 6 (1958) 335.Google Scholar
14. Ilschner, B., Archiv f.d. Eisenhuettenwesen 26 (1955) 59.Google Scholar
15. Doremus, R.H., Acta Met., 6 (1958) 674.Google Scholar
16. Christian, J.W.. The Theory of Transformation in Metals and Alloys, International Series on Materials Science and Technology Vol. 15, Pergamon Press, Oxford 1975.Google Scholar
17. Kohlraus, F., Ann. Phys., 12 (1847) 393.Google Scholar
18. Williams, G. and Watts, D.C., Trans. Faraday Soc, 66 (1970) 80.Google Scholar
19. Alvarez, F., Alegria, A., and Colmenero, J., Phys. Rev. B, 44 (1991) 7306.Google Scholar
20. Crank, J., The Mathematics of Diffusion, second edition, Oxford, Clarendon Press 1975.Google Scholar