Particle Deposition and Removal of Relevance to Wet Processing in Semiconductor Manufacturing

Removal of particulate contaminants from surfaces is a critical area in the processing of wafers to build integrated circuits and is typically done using wet chemical formulations. Strategies for particle removal require an understanding of particle deposition mechanisms. In the first part of this review paper, colloid chemical principles underlying particle deposition on surfaces is discussed. Specifically, the importance of van der Waals and electrical double layer interaction energy on particle-surface interaction is reviewed. This is followed by a description of commonly used particle removal methods in wafer processing, viz., megasonic cleaning, brush cleaning, and nanospray cleaning. The importance of particle deposition conditions used in research on particle removal efficiency is highlighted through a study on the effect of aging.