Unveiling superior chemical mechanical polishing properties of a novel shell-core structure: Insights from an atomic-scale perspective

Abstract

The precision polishing process plays a crucial role in the modern advanced semiconductor manufacturing field, making it imperative to develop excellent polishing abrasives through new techniques. In this study, we obtained well-defined spherical nano-composite polishing particles CeO2@SiO2 via posterior grafting synthesis, which have a clear core–shell structure and exhibit a high Ce3+ concentration. Atomic force microscopy revealed significant improvement in surface roughness of the abrasives on Si substrates, achieving the material removal rate (MRR) of 300 nm/min. MRR is closely correlated with the Ce3+ concentration. Combining aberration-corrected transmission electron microscopy with first-principles calculations demonstrated that surface oxygen vacancies and interfacial charge transfer were the primary origins of high Ce3+ concentration, and revealed the material removal mechanism. This work not only provides new insights into the process but also offers new routes for the development of novel polishing abrasives in the future.