Cleaning chemistries, silicon wafers

Effects of Various Chemistries on Silicon-Wafer Cleaning... 

Figures Illustration of (A) etched aluminumalloy (Guo etal., 2006), (B) laser-etched silicon wafer with using SF6 3.2kJ/m2 and (C) using OkJ/m (Baldacchini et al., 2006), (D) silicon wafer/photoresist layer overetched by SFg plasma before sonication, (E) after cleaning of residual photoresist and (F) micropillar structured silicon after buffered oxide etching. Images reprinted with permission from (A, D, and E) Elsevier, Copyright 2006,2005, and (B, C, and E) American Society, Copyright2006,2007. Adapted with permission of The Royal Society of Chemistry.

In brush cleaning, an alkaline chemistry such as NH4OH is often used to remove the particles such as particles of silica, alumina, glass, polystyrene latex (PSL), and silicon nitride from various wafers in the first brush. The basic chemistry is used mainly to increase the repulsive charge by the zeta potential between the particle and the substrate. 

---