Journal of Electronic Materials

, Volume 33, Issue 9, pp 1005–1011 | Cite as

In-situ cleaning and passivation of oxidized Cu surfaces by alkanethiols and its application to wire bonding

  • Caroline M. Whelan
  • Michael Kinsella
  • Hong Meng Ho
  • Karen Maex
Regular Issue Paper


The treatment of oxidized Cu surfaces using an alkanethiol as a reducing agent has been investigated. Exposure to a dilute solution of 1-decanethiol resulted in the complete removal and/or conversion of CuO and subsequent formation of a passivating thiolate film, a so-called self-assembled monolayer (SAM), on the underlying Cu/Cu2O surface as evidenced by x-ray photoelectron spectroscopy (XPS) analysis. Morphological changes, monitored by scanning electron microscopy (SEM) and atomic force microscopy (AFM), revealed transformation of the rough, porous CuO layer into a comparatively smooth Cu/Cu2O surface. Experiments performed on integrated circuit back-end-of-line (BEOL) die structures, comprising Cu/SiO2 bond pads used as substrates for Cu wire bonding, demonstrate the potential application of a thiol-based in-situ cleaning-passivation procedure in microelectronics.

Key words

Cu/Cu2in-situ cleaning and passivation alkanethiol wire bonding 


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Copyright information

© TMS-The Minerals, Metals and Materials Society 2004

Authors and Affiliations

  • Caroline M. Whelan
    • 1
  • Michael Kinsella
    • 3
  • Hong Meng Ho
    • 1
  • Karen Maex
    • 1
    • 2
  1. 1.IMECLeuvenBelgium
  2. 2.Department of Electrical EngineeringKatholieke Universiteit LeuvenHeverleeBelgium
  3. 3.Department of ChemistryTrinity CollegeDublin 2Ireland

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