Particle Size Analysis of Fumed Silica

Chemical Mechanical Polishing (CMP) technology is used as an indispensable fundamental technology in the manufacturing process of ultra-large-scale semiconductor integrated circuits (ULSI). CMP is a technique in which the surface of a substrate is softened, removed or flattened by chemical etching and frictional abrasion with a chemical slurry that contains abrasive particles.  Fumed silica abrasive particles are synthesized in a gas phase reaction in flame and are dispersed as secondary particles that are aggregates of primary particles. They are known to have thiogenic properties. Although the rate of polishing is high for fumed silica, its polishing precision is inferior to that of colloidal silica.