Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-20T01:34:08.385Z Has data issue: false hasContentIssue false

Internal Stress In Sputtered Silver Nickel Thin Films And Multilayers: Sputtering Pressure And Thickness Effects

Published online by Cambridge University Press:  10 February 2011

P. Gergaud
Affiliation:
MATOP, UPRESA CNRS 6088, Fac. de St Jerome, 13397 Marseille cedex 20, FRANCE
H. Yang
Affiliation:
LMS, Delft University of Technology, THE NETHERLANDS
C. PéLissonnier-Grosjean
Affiliation:
MATOP, UPRESA CNRS 6088, Fac. de St Jerome, 13397 Marseille cedex 20, FRANCE
A. J. Bottger
Affiliation:
LMS, Delft University of Technology, THE NETHERLANDS
P. Sandström
Affiliation:
DPMT, Linköping University, SWEDEN
J. E. Sundgren
Affiliation:
DPMT, Linköping University, SWEDEN
O. Thomas
Affiliation:
MATOP, UPRESA CNRS 6088, Fac. de St Jerome, 13397 Marseille cedex 20, FRANCE
Get access

Abstract

Nanometer thick films are often in a state of high residual stress. This may strongly influence physical properties such as magnetic anisotropy. The aim of our study is to investigate whether the overall stress in multilayers may be tailored via the control of the sputtering parameters or of the individual thicknesses. The coatings investigated were deposited at room temperature by magnetron sputtering on oxidised silicon substrates. Ag/Ni multilayers of superperiod between 4 to 20 nm and thin films (Ag or Ni) 200 nm thick have been deposited under a krypton partial pressure varying between 1 and 8 mTorr. Internal stress measurements were performed by curvature method and x-ray diffraction sin2ψ method. The latter one allows the determination of the stress and of the stress-free lattice parameter in the Ag or the Ni layers whereas the first one gives rise to a measure of the average stress in the coating. The main results are the followings: (i) The stress in Ni thin films changes from compressive to tensile at a pressure between 2 and 5 mTorr whereas Ag thin films are sligthly tensile whatever the pressure; (ii) The stress in multilayers is tensile in Ag and Ni and decreases with sublayer thickness; (iii) The stress free lattice parameter of Ag in thin films or multilayers is independent of the Kr pressure and of the layer thickness and is equal to the bulk value; (iv) On the opposite, the stress-free lattice parameter of nickel decreases with the layer thickness in multilayers and is equal to the bulk value in thin films. These results are discussed in terms of the respective influence of interfacial intermixing and atomic peening mechanism.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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 » Thornton, J. A., Greene, J. E., in “Handbook of deposition technologies for films and coatings”, ed. Bunshah, R. F.; NoYes Publications, New Jersey, 1994, p.262 Google Scholar
«2» Stoney, G. G., Proc. Roy. Soc. London A 82, 1909, p.172 Google Scholar
«3» Ruud, J.A., Witrouw, A., Spaepen, F., J. Appl. Phys. 74, 1993, p.2517 Google Scholar
«4» Gergaud, P., Labat, S., Yang, H., Bottger, A., Sandström, P., Erik, Svedberg, Mittemeijer, E.J., Sundgren, J.E., Thomas, O., MRS Symposium Proc. 472, 1997, p. 299 Google Scholar
«5» Flinn, P., Gardner, D., Nix, W., IEEE Trans. Elec. Devices ED–34, 1987, p. 689 Google Scholar
«6» Noyan, I.C., Cohen, J. B., « Residual stress, Measurement by Diffraction and Interpretation », Springer, New York, 1987 Google Scholar
«7» Segmuller, A., Murakami, M., Thin Films from Free Atoms and particles, K.J., Klabunde, Ed., Academic press, New york, 1985, p.325 Google Scholar
«8» Gergaud, P., Labat, S. and Thomas, O., Thin Solid Films, 319, 1998, p.9 Google Scholar
«9» Labat, S., Chapter V, Ph. D. Thesis, Université de Marseille III, 1998 Google Scholar
«10» Labat, S., Gergaud, P., Thomas, O., Gilles, B., Marty, A., submitted to Appl. Phys. Lett., 1998 Google Scholar
«11» Floro, J.A., Chason, E., Appl. Phys. Lett. 69, 1996, p. 3830 Google Scholar