Theremoval of nanoparticles is becoming increasingly challenging as the minimumlinewidth continues to decrease in semiconductor manufacturing. In this paper,the removal of nanoparticles from flat substrates using acoustic streamingis investigated. Bare silicon wafers and masks with a 4 nmsilicon cap layer are cleaned. The silicon-cap films are usedin extreme ultraviolet masks to protect Mo–Si reflective multilayers. Theremoval of 63 nm polystyrene latex (PSL) particles from these substratesis conducted using single-wafer megasonic cleaning. The results show higherthan 99% removal of PSL nanoparticles. The results also showthat dilute SC1 provides faster removal of particles, which isalso verified by the analytical analysis. Particle removal from the4 nm Si-cap substrate is slightly more difficult as compared tobare silicon wafers. The experimental results show that the removalof nanoparticles takes a relatively long removal time. Numerical simulationsshowed that the long time is due to particle oscillatorymotion and redeposition, and that this phenomenon is not observedin the removal of sub-µm or larger size particles.


Originally published in Journal of the Electrochemical Society, v.153, no.9, pp. G846-G850 (2006). doi:10.1149/1.2217287


molybdenum, silicon, elemental semiconductors, polymers, nanoparticles, acoustic streaming, optical multilayers, ultrasonic cleaning, masks, ultraviolet lithography

Subject Categories

Nanoparticles, Acoustic streaming, Semiconductors


Electronic Devices and Semiconductor Manufacturing | Nanoscience and Nanotechnology


The Electrochemical Society

Publication Date


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Copyright 2006. All rights reserved. Except as provided under U.S. copyright law, this work may not be reproduced, resold, distributed, or modified without the express permission of The Electrochemical Society (ECS). The archival version of this work was published in Journal of the Electrochemical Society, v.153, no.9, pp. G846-G850 (2006).

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The Electrochemical Society, Inc.

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