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

•Surface doping of CeO2 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 CeO2 is largely improved after doping.•Doped CeO2 as CMP abrasive improves the polishing rate of SiO2 and surface quality. Ce3+ in CeO2, rather than Ce4+, is believed to provide assistance to the breaking up of SiO bond during chemical mechanical polishing (CMP) of silica. In the paper, lanthanide metals (La, Nd and Yb) doped CeO2 nanoparticles were synthesized by modified incipient impregnation method in order to improve the content of Ce3+ in CeO2 as polishing. X-ray photoelectron spectroscopy (XPS) experiments and density function theory (DFT) calculation demonstrate this approach could achieve surface doping of CeO2 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 CeO2 as abrasive particles. Especially for Nd/CeO2, 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.