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

• Surface doping of CeO 2 as CMP abrasives was done using La, Nd and Yb. • O vacancy formation energy and Ce3+ content was calculated by DFT and XPS. • Ce3+ content of CeO 2 is largely improved after doping. • Doped CeO 2 as CMP abrasive improves the polishing rate of SiO 2 and surface quality. Ce3+ in CeO 2 , rather than Ce4+, 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 Ce3+ 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 Ce3+ 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 Ce3+ 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. [ABSTRACT FROM AUTHOR]