RE (La, Nd and Yb) doped CeO2 abrasive particles for chemical mechanical polishing of dielectric materials: Experimental and computational analysis

Ce 3+ in CeO 2 , rather than Ce 4+ , is believed to provide assistance to the breaking up of Si O bond during chemical mechanical polishing (CMP) of silica. In the paper, lanthanide metals (La, Nd and Yb) doped CeO 2 nanoparticles were synthesized by modified incipient impregnation method in order to improve the content of Ce 3+ in CeO 2 as polishing. X-ray photoelectron spectroscopy (XPS) experiments and density function theory (DFT) calculation demonstrate this approach could achieve surface doping of CeO 2 nanoparticles, and facilitates the formation of oxygen vacancy and Ce 3+ content. CMP experiments show that the polishing rate and the surface quality of silica wafer are obviously improved by using the doped CeO 2 as abrasive particles. Especially for Nd/CeO 2 , content of Ce 3+ increases from 0.146 to 0.235, the polishing rate of silica is accelerated by 29.6% in alkaline slurries, and a better surface quality (Sa = 9.6 Å) is obtained.