Highly dispersed Gd-CeO2 nanocrystals supported on mesoporous silica composite particles towards photochemical (photo-assisted chemical) mechanical polishing

Nanoparticles (NPs) are widely used in polishing slurries for ensuring desired material removal and global planarization. Herein, novel multicomponent core-shell abrasive systems have been fabricated via an efficient chemical approach towards photochemical (photo-assisted chemical) mechanical polishing (PCMP) processes. The developed composite particles involved low-modulus mesoporous silica (mSiO2) cores and high-activity Gd-doped ceria (CeO2) shells. Compared to commercial CeO2 NPs, the mSiO2@CeGdO2 abrasives enabled superior fused silica surface quality in both CMP and PCMP tests. Furthermore, the as-proposed composites allowed an evident removal efficiency enhancement in the presence of ultraviolet light radiation. The improved polishing performance can be attributed to (i) the optimization of interfacial contact state and material removal behavior, (ii) the increasements of trivalent cerium and oxygen vacancy, and (iii) the enhancement of photochemical and tribochemical activities of the mSiO2@CeGdO2 heterostructured abrasive systems. The purpose of this work is to provide some contributions to the rational design and fabrication of functional abrasive systems for high-performance PCMP and other field-assisted finishing practices through abrasive structure regulation, surface chemistry, and defect engineering.