Vacuum ultraviolet irradiation treatment for reducing goldgold bonding temperature

Akiko Okada, Shuichi Shoji, Masatsugu Nimura, Akitsu Shigetou, Katsuyuki Sakuma, Jun Mizuno*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


Lowerature AuAu bonding was achieved under vacuum ultraviolet irradiation in the presence of oxygen gas (VUV/O3). The Au surfaces obtained after the VUV/O3 treatment were analyzed by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) measurements. The results indicate that the amount of carbon-based contaminants was dramatically decreased and that there was no serious damage to Au surfaces caused by the VUV/O3 treatment. The AuAu bonding temperature was successfully reduced to 150°C after the VUV/ O3 treatment. The average shear strength was approximately 56 MPa, and cross-sectional scanning electron microscopy (SEM) images of the bonded samples confirmed the absence of voids and cracks. Therefore, VUV/O3 treatment is highly effective for achieving lowerature AuAu bonding.

Original languageEnglish
Pages (from-to)2139-2143
Number of pages5
JournalMaterials Transactions
Issue number11
Publication statusPublished - 2013


  • Bonding
  • Flip chip
  • Gold
  • Micro-bump
  • Three-dimensional integration
  • Vacuum ultraviolet

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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