Removal of Particles on Si Wafers in SC-1 Solution

Hiroyuki KAWAHARA  Kenji YONEDA  Izumi MUROZONO  Yoshihiro TODOKORO  

IEICE TRANSACTIONS on Electronics   Vol.E77-C   No.3   pp.492-497
Publication Date: 1994/03/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Quarter Micron Si Device and Process Technologies)
Category: Process Technology
particle,  SC-1 solution,  etching,  Van der Waals force,  cleaning,  

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We have investigated the relationship between particle removal efficiency and etched depth in SC-1 solution (the mixture composed of ammonium hydroxide, hydrogen peroxide and DI water) for Si wafers. The Si etching rate increases with increasing NH4OH (ammonium hydroxide) concentration. The particle removal efficiency depends on the etched Si depth, and is independent of NH4OH concentration. The minimum required Si etching depth to get over 95% particle removal efficiency is 4 nm. Particles on the Si wafers exponentially decrease with increasing the etched Si depth. However the particle removal efficiency is not affected by particle size ranging from 0.2 to 0.5 µm. The particle removal mechanism on the Si wafers in SC-1 solution is dominated by the lift-off of particles due to Si undercutting and redeposition of the removed particle.