Kaufmann, Jens Georg and Desmulliez, Marc P. Y. and Tian, Yingtao and Price, Dennis and Hughes, Mike and Strusevich, Nadia and Bailey, Chris and Liu, Changqing and Hutt, David (2009) Megasonic agitation for enhanced electrodeposition of copper. Microsystem Technologies, 15 (8). pp. 1245-1254. ISSN 0946-7076
Full text not available from this repository.Abstract
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.