Improving the Dispersion Stability and Chemical Mechanical Polishing Performance of CeO<sub>2</sub> Slurries
Wang Ye, Baoguo Zhang, Wu Pengfei, Liu Min, Dexing Cui, Xian Wenhao
Abstract
The dispersion stability of CeO 2 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 CeO 2 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 CeO 2 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 Ce 3+ ). Moreover, CMP experiments showed that the CeO 2 slurry using acetic acid as the adjusting agent had a higher removal rate (4139 Å min −1 ).