Size Effect on Crack Formation in Cu/Ta and Ta/Cu/Ta Thin Film Systems

We’re sorry, something doesn't seem to be working properly.

Please try refreshing the page. If that doesn't work, please contact support so we can address the problem.

Abstract

Layered structures of Cu and Ta thin films on silicon are well established for many technological applications in microelectronics. Electronic circuits used for flexible displays or wearable electronics are becoming increasingly popular. For such applications, the Cu/Ta system must be transferred to flexible substrates, incorporating a design rule for several percent of total strain. We have investigated the deformation behaviour of different Cu/Ta and Ta/Cu/Ta thin film systems on a flexible polyimide substrate subjected to total strains of more than 5%. A novel synchrotron X-ray diffraction technique allowed us to characterize the evolution of mechanical stress in very thin metallic films during isothermal tensile tests. We found that samples with a Cu film thickness below 300 nm showed a sudden stress decrease at a total strain of about 2.5%. This stress drop was attributed to fracture of the entire film system, initiated by cracks in the Ta layers.

This is a preview of subscription content, access via your institution.

References

  1. 1.

    W.D. Nix, Metall. Trans. A 20A, 2217–45 (1989).

    CAS  Article  Google Scholar 

  2. 2.

    E. Arzt, Acta Mater. 46, 5611–26 (1998).

    CAS  Article  Google Scholar 

  3. 3.

    R. Venkatraman and J.C. Bravman, J. Mater. Res. 7 (8), 2040–48 (1992).

    CAS  Article  Google Scholar 

  4. 4.

    R.P. Vinci, E.M. Zielinski and J.C. Bravman, Thin Solid Films 262, 142–53 (1995).

    CAS  Article  Google Scholar 

  5. 5.

    Y.L. Shen, S. Suresh, M.Y. He, A. Bagchi, O. Kienzle, M. Rühle and A.G. Evans, J. Mater. Res. 13 (7), 1928–37 (1998).

    CAS  Article  Google Scholar 

  6. 6.

    T.J. Balk, G. Dehm and E. Arzt, Acta Mater. 51, 4471–85 (2003).

    CAS  Article  Google Scholar 

  7. 7.

    K. Holloway and P.M. Fryer, Appl. Phys. Lett. 57 (17), 1736–38 (1990).

    CAS  Article  Google Scholar 

  8. 8.

    J.A. Rogers, Z. Bao, K. Baldwin, A. Dodabalapur, B. Crone, V.R. Raju, V. Kuck, H. Katz, K. Amundson, J. Ewing and P. Drzaic, Proc. Natl. Acad. Sci. USA 98 (9), 4835–40 (2001).

    CAS  Article  Google Scholar 

  9. 9.

    E.R. Post, M. Orth, P.R. Russo and N. Gershenfeld, IBM Syst. J. 39, 840–60 (2000).

    Article  Google Scholar 

  10. 10.

    J. Böhm, P. Gruber, R. Spolenak, A. Stierle, A. Wanner and E. Arzt, Rev. Sci. Instrum. 75 (4), 1110–19 (2004).

    Article  Google Scholar 

  11. 11.

    J. Böhm, P. Gruber, R. Spolenak, A. Wanner and E. Arzt, these proceedings, P1.6.

  12. 12.

    L.G. Feinstein and R.D. Huttemann, Thin Solid Films 16, 129–45 (1973).

    CAS  Article  Google Scholar 

  13. 13.

    Gruber et al., work in progress.

  14. 14.

    J.L. Beuth, Int. J. Solids Structures 29, 1657–75 (1992).

    Article  Google Scholar 

  15. 15.

    Z.C. Xia and J.W. Hutchinson, J. Mech. Phys. Solids 48, 1107–31 (2000).

    CAS  Article  Google Scholar 

Download references

Acknowledgments

The authors would like to thank the beamline team of the MPI-MF-Surface-Diffraction-Beamline at ANKA (R. Weigel, N. Kaspar, A. Rühm and A. Stierle) for their excellent technical support as well as T. Wagner and F. Thiele of the MPI Thin Film Laboratory for sample preparation.

Author information

Affiliations

Authors

Corresponding author

Correspondence to P. Gruber.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Gruber, P., Böhm, J., Wanner, A. et al. Size Effect on Crack Formation in Cu/Ta and Ta/Cu/Ta Thin Film Systems. MRS Online Proceedings Library 821, 72–78 (2004). https://doi.org/10.1557/PROC-821-P2.7

Download citation