Functional Composite Modification of Cubic CeO2 Nanoparticles for Enhanced Dispersion and Polishing

Abstract

To address agglomeration, poor dispersion stability, and the trade-off between removal rate and surface quality of nano-CeO₂ abrasives in chemical mechanical polishing (CMP), this work focuses on cubic CeO₂ nanoparticles (C−CeO₂) with exposed (100) facets and systematically compares sodium dodecyl sulfate (SDS)-based composite modifications with 3-glycidyloxypropyltrimethoxysilane (GPTMS), polyvinyl alcohol (PVA), oleic acid (OA), and 2-methylpiperazine (2 MP). Comprehensive characterizations were used to elucidate the structure−property relationships between functional groups, interfacial interactions, and polishing performance. Results show that SDS-based composite modification suppresses nanoparticle agglomeration through synergistic electrostatic and steric effects. Among the four systems, C−CeO₂-SDS-GPTMS exhibits the best dispersion, wettability, and Ce³⁺ retention due to stable Si−O−Ce bonds, achieving a material removal rate (MRR) of 3230 Å/min (∼52% increase) and an ultra-low Sq of 0.0321 nm on a 5 × 5 μm SiO₂ dielectric layer. The PVA system balances high removal rate and low damage; OA shows stable adsorption but moderate dispersibility, whereas 2 MP exhibits the poorest performance because of weak coordination and severe hydrophobic agglomeration. Overall, the effectiveness of composite modification depends strongly on interfacial bonding strength and hydrophilic-hydrophobic balance. This study provides a systematic theoretical and experimental foundation for designing high-performance nano-CeO₂-based CMP abrasives.