Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-28T08:15:18.576Z Has data issue: false hasContentIssue false

Nanoindentation of Au and Pt/Cu thin films at elevated temperatures

Published online by Cambridge University Press:  03 March 2011

Alex A. Volinsky*
Affiliation:
University of South Florida, Department of Mechanical Engineering, Tampa, Florida 33620
Neville R. Moody
Affiliation:
Sandia National Laboratories, Livermore, California 94550
William W. Gerberich
Affiliation:
University of Minnesota, Department of Chemical Engineering and Materials Science, Minneapolis, Minnesota 55455
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

This paper describes the nanoindentation technique for measuring sputter-deposited Au and Cu thin films’ mechanical properties at elevated temperatures up to 130 °C. A thin, 5-nm Pt layer was deposited onto the Cu film to prevent its oxidation during testing. Nanoindentation was then used to measure elastic modulus and hardness as a function of temperature. These tests showed that elastic modulus and hardness decreased as the test temperature increased from 20 to 130 °C. Cu films exhibited higher hardness values compared to Au, a finding that is explained by the nanocrystalline structure of the film. Hardness was converted to the yield stress using both the Tabor relationship and the inverse method (based on the Johnson cavity model). The thermal component of the yield-stress dependence followed a second-order polynomial in the temperature range tested for Au and Pt/Cu films. The decrease in yield stress at elevated temperatures accounts for the increased interfacial toughness of Cu thin films.

Type
Articles
Copyright
Copyright © Materials Research Society 2004

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.Read, D.T. andDally, J.W.: A new method for measuring the strength and ductility of thin films. J. Mater. Res. 8, 1542 (1993).Google Scholar
2.Weihs, T.P., Hong, S., Bravman, J.C. andNix, W.D.: Mechanical deflection of cantilever microbeams: A new technique for testing the mechanical properties of thin films. J. Mater. Res. 3, 931 (1988).CrossRefGoogle Scholar
3.Baker, S.P. andNix, W.D.: Mechanical properties of compositionally modulated Au–Ni thin films: Nanoindentation and microcantilever deflection experiments. J. Mater. Res. 9 3131, 3145 (1994).Google Scholar
4.Pharr, G.M., Harding, D.S. andOliver, W.C. Mechanical Properties and Deformation Behavior of Materials Having Ultra-Fine Microstructures, in Proceedings of the NATO Advanced Study Institute, edited by Nastasi, M., Parkin, D.M., and Gleiter, H.. (Kluwer Academic Publishers, Netherlands, 1993), pp. 449461.Google Scholar
5.Doerner, M. andNix, W.D.: A method for interpreting the data from depth-sensing indentation instruments. J. Mater. Res. 1, 601 (1986).Google Scholar
6.Pharr, G.M., Oliver, W.C. andBrotzen, F.: On the generality of the relationship between contact stiffness, contact area, and elastic modulus during indentation. J. Mater. Res. 7, 613 (1992).Google Scholar
7.Oliver, W.C. andPharr, G.M.: J. Mater. Res. 7, 1564 (1992).CrossRefGoogle Scholar
8.Tabor, D.The Hardness of Metals (Claredon Press, Oxford, U.K., 1951) p. 174.Google Scholar
9.Kramer, D., Huang, H., Kriese, M., Robach, J., Nelson, J., Wright, A., Bahr, D. andGerberich, W.W.: Yield strength predictions from the plastic zone around nanocontacts. Acta Mater. 47, 333 (1999).CrossRefGoogle Scholar
10.Kramer, D.E., Volinsky, A.A., Moody, N.R. andGerberich, W.W.: Substrate effects on indentation plastic zone development in thin soft films. J. Mater. Res. 16, 3150 (2001).Google Scholar
11.Nix, W.D.: Mechanical properties of thin films. Metal. Trans. A 20A, 2217 (1989).Google Scholar
12.Wei, Y. andHutchinson, J.W.: Steady-state crack growth and work of fracture for solids characterized by strain gradient plasticity. J. Mech. Phys. Solids 45, 1137 (1997).Google Scholar
13.Inui, H., Matsumuro, M., Wu, D-H. andYamaguchi, M.: Temperature dependence of yield stress, deformation mode and deformation structure in single crystals of TiAl (Ti-56 at.%Al). Philos. Mag. A 75, 395 (1997).Google Scholar
14.Lucas, B.N. andOliver, W.C.Indentation power-law creep of high-purity indium. Metall. Mater. Trans. A 30, 601 (1999).CrossRefGoogle Scholar
15.Lucas, B.N. An experimental investigation of creep and viscoelastic properties using depth-sensing indentation techniques, Ph.D. Dissertation, The University of Tennessee, Knoxville, TN, 1997.Google Scholar
16.Stach, E.A., Freeman, T., Minor, A.M., Owen, D.K., Cumings, J., Wall, M.A., Chraska, T., Hull, R., Morris, J.W. Jr.Zettl, A. andDahmen, U.: Development of a nanoindenter for in-situ transmission electron microscopy and microanalysis. Microsc. and Microanal. 7, 507 (2001).Google Scholar
17.Beake, B.D. andSmith, J.F.: High-temperature nanoindentation testing of fused silica and other materials. Philos. Mag. A 82, 2179 (2003).Google Scholar
18.Smith, J.F. andZheng, S.: High temperature nanoscale mechanical property measurements. Surf. Eng. 16, 143 (2000).Google Scholar
19. MTS Systems Corporation. Variable temperature nanoindentation (Oak Ridge, TN, 2004). World wide web: http://www.mts.com/nano/Variable_temp.htm.Google Scholar
20.Volinsky, A.A. The role of geometry and plasticity in thin ductile film adhesion, Ph.D. Dissertation, University of Minnesota, Minneapolis, MN, 2000.Google Scholar
21. Thermal Accessory for MultiMode and Dimensions Scanning Probe Microscopes. Support Note No. 252, Rev. B, Digital Instruments, 1998.Google Scholar
22.Ivanov, D., Daniels, R. andMagonov, S.Exploring the high-temperature AFM and its use for studies of polymers. Digital Instruments Application Notes, 2001.Google Scholar
23.Xia, X. Micro/nanoprobing measurement of polymer coating/film mechanical properties, Ph.D. Dissertation, University of Minnesota, 2000.Google Scholar
24.Sherby, O.D. In Nature and Properties of Materials: An Atomistic Interpretation, edited by Pask, J. (Wiley, New York, 1967) p. 376.Google Scholar
25.Burakovsky, L., Greeff, C.W. andPreston, D.L.: Analytic model of the shear modulus at all temperatures and densities. Phys. Rev. B 67, 094107 (2003).Google Scholar
26.Collard, S.M. andMcLellan, R.B.: High-temperature elastic constants of gold single-crystals. Acta Metall. Mater. 39, 3143 (1991).Google Scholar
27.Vinci, R.P., Zielinski, E.M. andBravman, J.C.: Thermal strain and stress in copper thin films. Thin Solid Films 262, 142 (1995).Google Scholar
28.Gerberich, W.W., Volinsky, A.A., Tymiak, N.I. andMoody, N.R.: A brittle to ductile transition (BDT) in adhered thin films, in Thin Films-stresses and Mechanical Properties VIII, edited by Vinci, R., Kraft, O., Moody, N., Besser, P., and Snaffer, E. II (Mater. Res. Soc. Symp. Proc. 594, Warrendale, PA, 2000). p. 351.Google Scholar
29.Tymiak, N.I., Volinsky, A.A., Kriese, M.D., Downs, S.A. andGerberich, W.W.: The role of plasticity in bi-material fracture with ductile interlayers. Metall. and Mater. Trans. A 31A, 863 (2000).Google Scholar
30.Volinsky, A.A., Vella, J., Adhihetty, I.S., Sarihan, V., Mercado, L., Yeung, B.H. andGerberich, W.W.: Adhesion quantification of post-CMP copper to amorphous SiN passivation by nanoindentation, in Fundamentals of Nanoindentation and Nanotribiology II, edited by Baker, S.P., Cook, R.F., Corcoran, S.G., and Moody, N.R. (Mater. Res. Soc. Symp. Proc. 649, Warrendale, PA, 2001) Q 5.3.1.Google Scholar
31.Volinsky, A.A., Moody, N.R. andGerberich, W.W.: Interfacial toughness measurements for thin films on substrates. Acta Mater. 50, 441 (2002).Google Scholar
32.Volinsky, A.A., Bahr, D.F., Kriese, M.D., Moody, N.R. andGerberich, W.W. Nanoindentation methods in interfacial fracture testing, Chapter 13 in Comprehensive Structural Integrity, edited by Milne, I., Ritchie, R.O., and Karihaloo, B., in Volume 8: Interfacial and Nanoscale Failure, edited by Gerberich, W.W. and Yang, W. (Elsevier, New York, 2003).Google Scholar
33. Taher Saif: University of Illinois at Urbana-Champaign, Private Communication.Google Scholar
34.Zener, C., van Winkle, D., and Nielson, H.: Trans. A.I.M.E. 147, 98 (1942).Google Scholar
35. Ting-Sui Ke: Phys. Rev. 71,533 (1947).Google Scholar