Preparation of mesoporous CeO2@MOF-5 abrasives for efficient polishing in chemical mechanical polishing

Abstract

In chemical mechanical polishing (CMP), abrasives play a pivotal role in determining the material removal rate (MRR) and the resulting surface quality. While traditional cerium oxide (CeO₂) abrasives suffer from limitations in dispersion stability and the removal of post-polishing residues, a novel mesoporous CeO₂@MOF-5 composite abrasive was developed to enhance Ce³⁺ ion concentration for improved polishing performance. The composite abrasives were structurally characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), and were found to exhibit hierarchical porosity and uniform morphology. X-ray photoelectron spectroscopy (XPS) analysis revealed an increased concentration of Ce³⁺ ions compared to pure CeO₂, which was attributed to the synergistic interaction between CeO₂ and the MOF-5 framework. CMP tests demonstrated that composites containing 2.00 wt% MOF-5 achieved optimal performance, attaining an MRR of 17.37 μm/h—representing a 39 % enhancement over pure CeO₂ abrasives (10.60 μm/h)—while simultaneously reducing the post-polishing surface roughness (Sa) to 0.31 nm, which was significantly lower than that of conventional CeO₂ (Sa = 1.81 nm). Wettability analysis via contact angle measurements showed enhanced slurry-substrate interactions for CeO₂@MOF-5, and tribological studies revealed a higher dynamic friction coefficient that promoted increased interfacial shear stress. These combined effects enhance the mechanochemical synergy during CMP, thereby enabling both high efficiency and atomic-level surface finishing. This work offers a strategic pathway for developing next-generation composite abrasives with tunable chemical activity and mechanical robustness.