Journal of Materials Science

, Volume 42, Issue 7, pp 2347–2357 | Cite as

Microstructural evolution of gold–aluminum wire-bonds

  • Adi Karpel
  • Giyora Gur
  • Ziv Atzmon
  • Wayne D. Kaplan


The purpose of this study is to understand the morphological changes that occur during annealing of Al–Au wire-bonds, by analyzing the interface region of annealed model wire-bonded samples between 5N (99.999%) Au wires and Al pads. Due to the small length scale of the intermetallic region at the interface of the bond, the analysis was done using scanning/transmission electron microscopy combined with energy dispersive spectroscopy. Samples were prepared using a dual-beam focused ion beam system. Microstructural characterization showed that during annealing, a Au-rich intermetallic region was formed under the bond and at the periphery of the bond. Two types of failures occurred during annealing: crack formation at the bond periphery due to an increase in volume during intermetallic growth and the formation of stresses; and oxidation of the AlAu4 phase adjacent to the Au ball, which resulted in the formation of continuous cracks between the Au ball and the intermetallic region. The characteristic void-line found inside the intermetallic region played no part in failure that occurred during exposure to elevated temperatures.



The authors thank the Russell Berrie Nanotechnology Institute at the Technion for use of the FIB, and I. Popov for assistance with use of the TEM.


  1. 1.
    Harman G (1997) Wire-bonding in microelectronics materials process reliability and yield. McGraw-Hill Publishers, NYGoogle Scholar
  2. 2.
    Zhang X, Yan TT (2006) Thin Solid Films 504[1–2]:355Google Scholar
  3. 3.
    Noolu NJ, Murdeshwar NM, Ely KJ, Lippold JC, Baeslack WA (2004) J Mater Res 19(5):1374CrossRefGoogle Scholar
  4. 4.
    Breach CD, Tok CW, Wulff F, Calpito D (2004) J Mater Sci 39(19):6125CrossRefGoogle Scholar
  5. 5.
    Maiocco L, Smyers D, Kadiyala S, Baker I (1990) Mater Charact 24(4):293CrossRefGoogle Scholar
  6. 6.
    Clatterbaugh GV, Weiner JA, Charles HK (1984) IEEE Trans Compon Hybrids Manufacture Technol 7(4):349CrossRefGoogle Scholar
  7. 7.
    Majni G, Nobili C, Ottaviani G, Costato M, Galli E (1981) J Appl Phys 52(6):4047CrossRefGoogle Scholar
  8. 8.
    Markwitz A, Matz W (1970) Surf Interface Anal 26(9):650CrossRefGoogle Scholar
  9. 9.
    Philofsky E (1970) Solid-State Electron 13(10):1391CrossRefGoogle Scholar
  10. 10.
    Xu C, Sritharan T, Mhaisalkar SG (2007) Scripta Mater 56(6):549CrossRefGoogle Scholar
  11. 11.
    Chang HS, Hsieh KC, Martens T, Yang A (2004) IEEE Trans Compon Pack Technol 27(1):155CrossRefGoogle Scholar
  12. 12.
    Ji H, Li M, Wang C, Bang HS, Bang HS (2007) Mater Sci Eng A 447(1–2):111Google Scholar
  13. 13.
    Williams DB, Carter BC (1996) Transmission electron microscopy. Plenum, New YorkGoogle Scholar
  14. 14.
    Karpel A, Kaplan WD, Atzmon Z, Gur G (2005) In: Havas D, Levine L (eds) Proceedings of the 2005 international symposium on microelectronics, IMAPS. p 325Google Scholar
  15. 15.
    Reyntjens S, Puers R (2001) J Micromech Microeng 11(4):287CrossRefGoogle Scholar
  16. 16.
    Karpel A, Gur G, Atzmon Z, Kaplan WD (2007) J Mater Sci, in press. doi 10.1007/s10853-007-1592-zGoogle Scholar
  17. 17.
    Bowden P, Brandon DG (1963) J Nuclear Mater 9(3):348CrossRefGoogle Scholar
  18. 18.
    Piao H, McIntyre NS (2001) Surf Interface Anal 31(9):874CrossRefGoogle Scholar
  19. 19.
    Xu C, Breach CD, Sritharan T, Wulff F, Mhaisalkar SG (2004) Thin Solid Films 462–463:357CrossRefGoogle Scholar
  20. 20.
    Villars P (1991) Pearson’s handbook of crystallographic data for intermetallic phases, 2nd ed. vol 1. ASM International, Materials Park, Ohio, p 652Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Adi Karpel
    • 1
  • Giyora Gur
    • 2
  • Ziv Atzmon
    • 2
  • Wayne D. Kaplan
    • 1
  1. 1.Department of Materials EngineeringTechnion – Israel Institute of TechnologyHaifaIsrael
  2. 2.Kulicke & Soffa Bonding ToolsYokneam EliteIsrael

Personalised recommendations