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Experimental Mechanics

, Volume 50, Issue 7, pp 993–997 | Cite as

A Sequential Tensile Method for Rapid Characterization of Extreme-value Behavior in Microfabricated Materials

  • B. L. BoyceEmail author
Article

Abstract

A high-throughput sequential tensile test method has been developed to characterize the fracture strength distribution of microfabricated polycrystalline silicon, the primary structural material used in microelectromechanical systems (MEMS). The resulting dataset of over 1,000 microtensile tests reveals subtle extreme-value behavior in the tails of the distribution, demonstrating that the common two-parameter Weibull distribution is inferior to a three-parameter Weibull model. The results suggest the existence of a cut-off or threshold stress (1.446 GPa for this particular material) below which tensile failure will not occur. The existence of a cut-off stress suggests that the material’s flaw size distribution and toughness distribution are both also bounded. From an application perspective, the cut-off stress provides a statistically-sound basis for reliable design. While the sequential method is demonstrated here for tensile strength distributions in polycrystalline silicon MEMS, the technique could be extended to a wide range of mechanical tests (bending strength, elastic modulus, fracture toughness, creep, etc.) for both microsystem and conventional materials.

Keywords

Silicon MEMS Fracture Strength Weibull 

Notes

Acknowledgements

The author would like to thank T. Crenshaw for laboratory support, Dr. J.R. Michael, B. McKenzie, R. Grant for SEM imaging, and Drs. J.W. Foulk, M.P de Boer, and E.D. Reedy, Jr. for useful discussions on this topic. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Supplementary material

ESM 1

Supplementary Material (MPG 9206 kb)

References

  1. 1.
    Weibull W (1951) A statistical distribution function of wide applicability. Journal of Applied Mechanics—Transactions of the ASME 18:293–297zbMATHGoogle Scholar
  2. 2.
    Zehnder AT, Sengupta D, Hines MA (2006) Methyl monolayers improve the fracture strength and durability of silicon nanobeams. Applied Physics Letters 89:231905Google Scholar
  3. 3.
    Chasiotis I, Knauss WG (2003) The mechanical strength of polysilicon films: Part 2. Size effects associated with elliptical and circular perforations. Journal of the Mechanics and Physics of Solids 51:1551–1572CrossRefGoogle Scholar
  4. 4.
    Corigliano A, De Masi B, Frangi A, Comi C, Villa A, Marchi M (2004) Mechanical characterization of polysilicon through on-chip tensile tests. Journal of Microelectromechanical Systems 13:200–219CrossRefGoogle Scholar
  5. 5.
    Givli S, Altus E (2006) Relation between stochastic failure location and strength in brittle materials. Journal of Applied Mechanics—Transactions of the ASME 73:698–701zbMATHCrossRefGoogle Scholar
  6. 6.
    Miller DC, Boyce BL, Dugger MT, Buchheit TE, Gall K (2007) Characteristics of a commercially available silicon-on-insulator MEMS material. Sensors & Actuators: A Physical 138:130–144CrossRefGoogle Scholar
  7. 7.
    Nemeth NN, Evans LJ, Jadaan OM, Sharpe WN, Beheim GM, Trapp MA (2007) Fabrication and probabilistic fracture strength prediction of high-aspect-ratio single crystal silicon carbide microspecimens with stress concentration. Thin Solid Films 515:3283–3290CrossRefGoogle Scholar
  8. 8.
    Boyce BL, Grazier JM, Buchheit TE, Shaw MJ (2007) Strength distributions in polycrystalline silicon MEMS. Journal of Microelectromechanical Systems 16:179–190CrossRefGoogle Scholar
  9. 9.
    Cacchione F, Corigliano A, De Masi B, Riva C (2005) Out of plane vs. in plane flexural behaviour of thin polysilicon films: mechanical characterization and application of the Weibull approach. Microelectronics and Reliability 45:1758–1763CrossRefGoogle Scholar
  10. 10.
    Ding JN, Wong PL, Yang JC (2006) Friction and fracture properties of polysilicon coated with self-assembled monolayers. Wear 260:209–214CrossRefGoogle Scholar
  11. 11.
    Tsuchiya T (2005) Tensile testing of silicon thin films. Fatigue and Fracture of Engineering Material and Structures 28:665–674CrossRefGoogle Scholar
  12. 12.
    Greek S, Ericson F, Johansson S, Schweitz JA (1997) In situ tensile strength measurement and Weibull analysis of thick film and thin film micromachined polysilicon structures. Thin Solid Films 292:247–254CrossRefGoogle Scholar
  13. 13.
    Boyce BL, Ballarini R, Chasiotis I (2008) An argument for proof testing brittle microsystems in high-reliability applications. Journal of Micromechanics and Microengineering 18:117001CrossRefGoogle Scholar
  14. 14.
    Hankins MG, Resnick PJ, Clews PJ, Mayer TM, Wheeler DR, Tanner DM et al (2003) Vapor deposition of amino-functionalized self-assembled monolayers on MEMS. Reliability, Testing, and Characterization of Mems/Moems Ii 4980:238–247Google Scholar
  15. 15.
    Kahn H, Tayebi N, Ballarini R, Mullen RL, Heuer AH (2000) Fracture toughness of polysilicon MEMS devices. Sensors and Actuators. A, Physical 82:274–280CrossRefGoogle Scholar
  16. 16.
    Chasiotis I, Cho SW, Jonnalagadda K (2006) Fracture toughness and subcritical crack growth in polycrystalline silicon. Journal of Applied Mechanics: Transactions of the ASME 73:714–722zbMATHCrossRefGoogle Scholar

Copyright information

© Society for Experimental Mechanics 2009

Authors and Affiliations

  1. 1.Sandia National LaboratoriesAlbuquerqueUSA

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