Effects of abrasive size and surfactant in nano ceria slurry for shallow trench isolation

The effects of the abrasive size and the surfactant concentration in ceria slurry on the removal rates for oxide and nitride films were investigated through a systematic chemical-mechanical-polishing (CMP) experiment. We found that the smaller the abrasives were, the more quickly the removal rates for both oxide and nitride films decreased with increasing surfactant concentration. This result was qualitatively explained by using a model in which abrasive particles move through a viscous layer caused by surfactant adsorption on the film surface being polished.