Nanoparticle removal mechanisms during Post-CMP cleaning

In this research, the synergistic interaction of a brush, an adhered particle, and a wafer surface was evaluated during post chemical mechanical polishing (CMP). The approach includes theoretical analysis combined with experiments. A theoretical model was used to predict the particle/wafer contact area and contact force in order to identify the maximum tangential force required to remove particle agglomerates. Experiments are carried out to validate the analysis and to further study the removal mechanisms. This research suggests that a combined effort between a brush and surfactant would be effective in removing small particles during cleaning. For large particles, the mechanical force would be the dominating factor.