Electronic metal–support interaction–driven photocatalytic chemical mechanical polishing of silicon carbide wafers using Ag-modified CeO2 slurry

An ultra-smooth silicon carbide (SiC) wafer surface is critical for the performance and longevity of semiconductor, optoelectronic, and high-temperature devices. In this study, a novel photocatalytic chemical mechanical polishing (CMP) strategy is proposed using Ag-loaded CeO 2 abrasives, in which Ag establishes strong electronic metal–support interactions (EMSI) with CeO 2 . This system achieves an ultra-low surface roughness of 0.086 nm while maintaining a high material removal rate of 445.5 nm/h. Under UV illumination, Ag nanoparticles function as electron sinks, suppressing electron–hole recombination and promoting the generation of reactive oxygen species (•OH and •O 2 − ), which rapidly oxidize the SiC surface into a softer SiO 2 layer. Concurrently, oxygen vacancies in CeO 2 act as critical active sites for Ce–O–Si bond formation, facilitating mechanical removal. The incorporation of Ag also effectively stabilizes oxygen vacancies by suppressing their passivation in strongly oxidizing slurries, thereby preserving their reactivity and enhancing the mechanical removal efficiency. This CeO 2 -based metal–support architecture furnishes advanced mechanistic insights and strategic design principles for CMP processes predicated on oxidation-facilitated removal pathways.