Megasonic agitation for enhanced electrodeposition of copper

Jens Georg Kaufmann, M. P Y Desmulliez, Yingtao Tian, Dennis Price, Mike Hughes, Nadia Strusevich, Chris Bailey, Changqing Liu, David Hutt

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)


In this paper we propose an agitation method based on megasonic acoustic streaming to overcome the limitations in plating rate and uniformity of the metal deposits during the electroplating process. Megasonic agitation at a frequency of 1 MHz allows the reduction of the thickness of the Nernst diffusion layer to less than 600 nm. Two applications that demonstrate the benefits of megasonic acoustic streaming are presented: the formation of uniform ultra-fine pitch flip-chip bumps and the metallisation of high aspect ratio microvias. For the latter application, a multi-physics based numerical simulation is implemented to describe the hydrodynamics introduced by the acoustic waves as they travel inside the deep microvias. © 2009 Springer-Verlag.

Original languageEnglish
Pages (from-to)1245-1254
Number of pages10
JournalMicrosystem Technologies
Issue number8
Publication statusPublished - Aug 2009

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