Effects of slurry particles on silicon dioxide CMP

The performance of chemical mechanical polishing (CMP) is determined by the dynamic contact behavior (sliding or rolling) of the slurry particles during polishing. The dynamic contact behavior of slurry particles is dependent on the shape, size, and concentration of particles. In this paper, the dynamic contact characteristics and their effects on the CMP performance were investigated through in situ friction force measurements, atomic force microscopy images, and polishing experiments. For sliding-dominated contact, the friction force remains unchanged within the specified testing period yielding scratch-type surface topography. For rolling-dominated contact, the friction force decreases with time under a constant solids loading, producing "shot-blast'' surface images. The polishing rate increases with solids loading of sliding particles and decreases with solids loading of rolling particles. Further optimization of the CMP process is possible by tailoring the dynamic contact of abrasive particles. (C) 2004 The Electrochemical Society.