Synthesis of high-performance Y3+ doped CeO2 nanoabrasives through regulating crystallization of cerium carbonate☆

Nano ceria abrasive is a key material for ultra-precision chemical mechanical polishing (CMP) of advanced integrated circuits and optical components. Ion doping is an effective method to improve the surface Ce 3+ content and chemical polishing effect. In this study, Y 3+ doped CeO 2 nanoabrasives were prepared by regulating the crystallization process of rare earth (RE) carbonate precursor based on the morphology inheritance between the precursors and the calcined products. In order to reduce the crystallization rate of cerium carbonate, the crystallization inert region with NH 4 HCO 3 to Ce 3+ molar ratio of 6 and reaction temperature of 60 °C was selected for precipitation reaction, and Y 3+ , a heavy RE with a large ion radius difference from Ce 3+ , was introduced into the precipitation system. The crystallization rate of cerium carbonate decreases obviously when Y 3+ doping content reaches 8 mol%, and amorphous nanoscale cerium carbonates begin to form. Using them as precursors, Y 3+ doped CeO 2 nanoabrasives with doping content of 8 mol%–20 mol% were prepared by calcination, and their physicochemical properties and polishing performance on K9 glass were studied. The prepared Y 3+ doped CeO 2 nanoabrasives have quasi-spherical morphology and the size is (50±15) nm. With Y 3+ doping amount increasing from 8 mol% to 20 mol%, the surface Ce 3+ concentration of the abrasive particles slightly increases from 20.0% to 21.7%, while the Young’s modulus decreases from 9.44 to 5.85 GPa. The sample with Y 3+ doping content of 10 mol% has the best performance in K9 polishing, with material removal rate of (234.0±4.0) nm/min and surface arithmetic mean height ( S a roughness) of (0.304±0.018) nm.