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John Michael Bernard, Oytun Guldkin & Ahmed Busnaina, NSF Center for Nano and Micro Contamination Control, Northeastern University, Boston, MA, USA Jingoo Park, Hanyang University, Ansan, Korea

ABSTRACT
As semiconductor device feature size continues to shrink, (currently at about 90 nm and expected to shrink to 25 nm by the year 2011 [1]), the removal of nano-scale particles continue to present tremendous challenges to the industry. High-intensity sound waves generate pressure fluctuations and acoustic streaming that provide sufficient hydrodynamic drag force to detach the particles from the surface [2,3]. Experimental evidence of physical removal of nano-particles using acoustic streaming is presented here for the first time. This article presents an investigation of the removal of nano- and submicrometer particles using a single-wafer megasonic cleaning tank. The single wafer tank is used to remove silica and silicon nitride particles from 200-mm silicon wafers using de-ionized water and SC1. In addition, preliminary tests of the removal of PSL nano particles with diameters 90, 63 and 28 nm were conducted using megasonic cleaning. The new single wafer process promises to be a fast (30–60 s) and effective cleaning process since the megasonic energy is distributed evenly on the wafer surface. The results show complete removal of PSL, silica and silicon nitride particles from silicon wafers has been demonstrated.