Controllable Synthesis of Monodisperse CeO₂ Nanoparticles with Tunable Sizes for Chemical-Mechanical Polishing

CeO₂ has been widely employed in semiconductors and ultraprecision optical polishing on account of its remarkable physical, chemical, and mechanical qualities. In this work, we present an efficient strategy to prepare monodisperse CeO₂ nanoparticles (NPs) with tunable sizes through a solvothermal method integrated with the following in situ surface modification procedure. The as-prepared CeO₂ NPs exhibit excellent monodispersibility and regular spherical morphology. Their average particle diameter can be readily regulated from 7.0 to 336.3 nm by adjusting the experimental conditions. Subsequently, these obtained CeO₂ NPs can be formulated into different slurries, and their polishing performances are tested. According to the results, the CeO₂ polishing slurry with an average particle size of 94.5 nm has a material removal rate of 481 nm/min and a surface roughness of 0.14 nm. In contrast, the commercial product has only a material removal rate of 214 nm/min and a surface roughness of 0.30 nm. Obviously, a much faster polishing rate and a smoother surface can be achieved. Furthermore, a smaller surface roughness of 0.11 nm can be realized when the average particle size of CeO₂ is reduced to 46.9 nm, which is beneficial to the ultraprecision optical polishing process and can greatly improve the quality of the material surface.