Hostname: page-component-84b7d79bbc-rnpqb Total loading time: 0 Render date: 2024-07-31T17:54:24.495Z Has data issue: false hasContentIssue false

Microstructures and Mechanical Properties of Sputtered Cu/Cr Multilayers

Published online by Cambridge University Press:  10 February 2011

A. Misra
Affiliation:
Los Alamos National Laboratory, MS K765, Los Alamos, NM 87545.
H. Kung
Affiliation:
Los Alamos National Laboratory, MS K765, Los Alamos, NM 87545.
T. E. Mitchell
Affiliation:
Los Alamos National Laboratory, MS K765, Los Alamos, NM 87545.
T. R. Jervis
Affiliation:
Los Alamos National Laboratory, MS K765, Los Alamos, NM 87545.
M. Nastasi
Affiliation:
Los Alamos National Laboratory, MS K765, Los Alamos, NM 87545.
Get access

Abstract

The microstructures and mechanical properties of Cu/Cr multilayers prepared by sputtering onto {100} Si substrates at room temperature are presented. The films exhibit columnar grain microstructures with nanoscale grain sizes. The interfaces are planar and abrupt with no intermixing, as expected from the phase diagram. The multilayers tend to adopt a Kurdjumov- Sachs (KS) orientation relationship: {110}Cr //{111}Cu, <111>Cr //<110>Cu. The hardness of the multilayered structures, as measured by nanoindentation, increase with decreasing layer thickness for layer thicknesses ranging from 200 nm to 50 nm, whereas for lower thicknesses the hardness of the multilayers is independent of the layer thickness. Dislocation-based models are used to interpret the variation of hardness with layer periodicity. The possible effects of factors such as grain size within the layers, density and composition of films and residual stress in the multilayers are highlighted. Comparisons are made to the mechanical properties of sputtered polycrystalline Cu/Nb multilayers which, like Cu/Cr, exhibit sharp fcc/bcc interfaces with no intermixing and a KS orientation relationship, but have a small shear modulus mismatch.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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.Nastasi, M., Parkin, D. and Gleiter, H., Mechanical Properties and Deformation Behavior of Materials Having Ultra-Fine Microstructures, Kluwer, Dortrecht, 1993.Google Scholar
2.Spitzig, W. A., Pelton, A. R. and Laabs, F. C., Acta Metall., 35, p 2427, 1987.Google Scholar
3.Adachi, K., Tsubokawa, S., Takeuchi, T. and Suzuki, H. G., J.Jp.Inst.Met., 61, p 397, 1997.Google Scholar
4.Mitchell, T. E., Lu, Y. C., Griffin, A. J., Nastasi, M. and Kung, H., J.Am.Cer.Soc., 80, p 1673, 1997.Google Scholar
5.Barnett, S. A. and Shinn, M., Ann. Rev. Mater. Sci., 24, p 481, 1994.Google Scholar
6.English, G. R., Simenson, G. F., Clemens, B. M. and Nix, W. D., Mat. Res. Soc. Sym. Proc., 356, p 363, 1995.Google Scholar
7.Embury, J. D. and Hirth, J. P., Acta Metall. Mater., 42, p 2051, 1994.Google Scholar
8.Koehler, J. S., Phys. Rev. B, 2, p 547, 1978.Google Scholar
9.Was, G. S. and Foecke, T., Thin Solid Films, 286, p 1, 1996.Google Scholar
10.Lin, J. C., Hoffman, R. A. and Panseri, N. J., Mat.Manf.Proc., 12, p 329, 1997.Google Scholar
11.Doolittle, L. R., Ph.D. Thesis (Cornell University, Ithaca, NY, 1987).Google Scholar
12.Doerner, M. F. and Nix, W. D., CRC Crit.Rev.Sol.St.Mat.Sci., 14, p 25, 1988.Google Scholar
13.Ruud, J. A., Witvrouw, A. and Spaepen, F., J.Appl.Phys., 74, p 2517, 1993.Google Scholar
14.Hansen, N. and Ralph, B., Acta Met., 30, p 411, 1982.Google Scholar
15.Brittain, C. P., Armstrong, R. W. and Smith, G. C., Scripta Met., 19, p 89, 1985.Google Scholar
16.Tambwe, M. F., Stone, D. S., Nastasi, M., Griffin, A. J., Kung, H. and Lu, Y. C., J.Mater.Res., submitted.Google Scholar
17.Lehoczky, S. L., J.Appl.Phys., 49, p 5479, 1978.Google Scholar
18.Kamat, S. V., Hirth, J. P. and Carnahan, B., Scripta Met., 21, p 1587, 1987.Google Scholar
19.Nix, W. D., Mat.Sci.Eng., A234-236, p 37, 1997.Google Scholar