Mechanically probing time-dependent mechanics in metallic MEMS

  • J. P. M. Hoefnagels
  • L. I. J. C. Bergers
  • N. K. R. Delhey
  • M. G. D. Geers
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)


The reliability of metallic micro-electromechanical systems (MEMS) depends on time-dependent deformation such as creep. To this end, a purely mechanical experimental methodology for studying the time-dependent deformation of free-standing microbeams has been developed. It is found most suitable for the investigation of creep due to the simplicity of sample handling and preparation and setup design, whilst maximizing long term stability and displacement resolution. The methodology entails the application of a constant deflection to a µm-sized free-standing aluminum cantilever beam for a prolonged period of time. After this load is removed, the deformation evolution is immediately recorded by acquiring surface height profiles through confocal optical profilometry. Image correlation and an algorithm based on elastic beam theory are applied to the full-field beam profiles to yield the tip deflection as a function of time. The methodology yields the tip deflection as function of time with ~3 nm precision.


Constant Deflection Elastic Hinge Elastic Beam Theory Permanent Deflection Differential Screw 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. 1.
    Van Spengen W. M., “MEMS reliability from a failure mechanisms perspective,” Microelectron. Reliab. 43, 7, pp. 1049-1060, 2003.CrossRefGoogle Scholar
  2. 2.
    Van Gils M., J. Bielen, and G. McDonald, “Evaluation of creep in RF MEMS devices,” proceedings of the EuroSimE 2007 conference, London, 2007.Google Scholar
  3. 3.
    Douglas M. R., “Lifetime estimates and unique failure mechanisms for a Digital Micromirror Device”, proceedings of the 36th Annual International Reliability Physics Symposium, Reno, U.S.A., pp. 9-16, 1998.Google Scholar
  4. 4.
    Dehm G., C. Motz, C. Scheu, H. Clemens, P. H. Mayrhofer, and C. Mitterer, “Mechanical size-effects in miniaturized and bulk materials,” Adv. Eng. Mater. 8, 11, pp. 1033-1045, 2006.Google Scholar
  5. 5.
    Arzt E., “Size effects in materials due to microstructural and dimensional constraints: A comparative review,” Acta Mater. 46, 16, pp. 5611-5626, 1998.CrossRefGoogle Scholar
  6. 6.
    Lee H. J., P. Zhang, and J. C. Bravman, “Stress relaxation in free-standing aluminum beams,” Thin Solid Films 476, 1, pp. 118-124, 2005.Google Scholar
  7. 7.
    Kalkman A. J., A. H. Verbruggen, and G. C. A. M. Janssen, “Young's modulus measurements and grain boundary sliding in free-standing thin metal films,” Appl. Phys. Lett. 78, 18, pp. 2673-2675, 2001.Google Scholar
  8. 8.
    Kalkman A. J., A. H. Verbruggen, G. C. A. M. Janssen, and S. Radelaar, “Transient creep in free-standing thin polycrystalline aluminum films,” J. Appl. Phys. 92, 9, pp. 4968-4975, 2002.Google Scholar
  9. 9.
    Hyun S., W. L. Brown, and R. P. Vinci, “Thickness and temperature dependence of stress relaxation in nanoscale aluminum films,” Appl. Phys. Lett. 83, 21, pp. 4411-4413, 2003.Google Scholar
  10. 10.
    Modlinski R., A. Witvrouw, P. Ratchev, R. Puers, J. M. J. Den Toonder, and I. De Wolf, “Creep characterization of al alloy thin films for use in mems applications,” Microelectron. Engg. 76, 1-4, pp. 272-278, 2004.Google Scholar
  11. 11.
    Modlinski R., P. Ratchev, A. Witvrouw, R. Puers, and I. D. Wolf, “Creep-resistant aluminum alloys for use in MEMS,” J. Micromech. Microengg. 15, 7, p. S165-S170, 2005.Google Scholar
  12. 12.
    Connolley T., P. E. Mchugh, and M. Bruzzi, “A review of deformation and fatigue of metals at small size scales,” Fatigue Fract. Eng Mater. Struct. 28, 12, pp. 1119-1152, 2005.Google Scholar
  13. 13.
    Hemker K. J. and W. N. Sharpe Jr, “Microscale characterization of mechanical properties,” Ann. Rev. Mater. Res. 37, pp. 92-126, 2007.Google Scholar
  14. 14.
    N. K. R. Delhey, “An experimental methodology to characterize time-dependent deformation in free-standing aluminum thin-films.” Eindhoven University of Technology, 2009.Google Scholar
  15. 15.
    Bielen J., J. Stulemeijer, D. Ganjoo, D. Ostergaard, and S. Noijen, “Fluid-electrostatic-mechanical modeling of the dynamic response of RF-MEMS capacitive switches,” proceedings of the EuroSimE 2008 conference, Freiburg im Breisgau, 2008Google Scholar

Copyright information

© Springer Science + Business Media, LLC 2011

Authors and Affiliations

  • J. P. M. Hoefnagels
    • 1
  • L. I. J. C. Bergers
    • 1
    • 2
  • N. K. R. Delhey
    • 1
  • M. G. D. Geers
    • 1
  1. 1.Department of Mechanical EngineeringEindhoven University of TechnologyEindhovenThe Netherlands
  2. 2.Foundation for Fundamental Research on Matter (FOM)UtrechtThe Netherlands

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