Improving the Dispersion Stability and Chemical Mechanical Polishing Performance of CeO2 Slurries

Abstract

The dispersion stability of CeO2 suspensions limits their widespread use in IC manufacturing because unstable slurries can be very damaging to the chemical mechanical polishing (CMP) flattening process. Therefore, this study is based on the use of wet ball milling in synergy with chemical agents to improve the dispersion stability of CeO2 slurry. Different organic acids were used as adjusting agents, including acetic acid, propionic acid, lactic acid, and phytic acid. The characterization of the dispersion stability showed that, compared to other organic acids, the CeO2 suspensions using acetic acid as a modest particle size distribution, good stability (zeta potential > 50 mV), monodispersity (polydispersity index < 0.1) and higher chemical activity (higher content of Ce3+). Moreover, CMP experiments showed that the CeO2 slurry using acetic acid as the adjusting agent had a higher removal rate (4139 Å min−1).