BiFeO 3 Nanoparticles for Chemical Mechanical Polishing of SiC: A Piezoelectric-Fenton-Like Synergistic Strategy

Traditional Fenton reaction has been widely investigated for enhancing oxidation efficiency in the chemical mechanical polishing (CMP) of silicon carbide (SiC). However, their applications in CMP are limited by the generation of insoluble iron precipitates and the instability of the Fe 2+ /Fe 3+ redox cycle, which results in low oxidation capacity. Herein, a sustainable CMP strategy based on the piezoelectric-Fenton-like reaction of bismuth ferrite (BiFeO 3 ) is reported. In this strategy, the piezoelectric effect activates and stabilizes the Fe 2+ /Fe 3+ redox cycle by enabling polarization-induced electrons to participate in the reduction of Fe 3+ , thereby sustaining continuous and efficient generation of reactive radicals. BiFeO 3 abrasives with a rhombohedral perovskite structure are both piezoelectric and catalytically active as Fe-based Fenton-like agents. This combination thus significantly enhances the oxidation of single-crystal SiC wafers by the slurry, while the abrasives themselves also act as mechanical carriers to remove the oxide products. Consequently, an ultra-smooth surface with a roughness of 0.287 nm and a high material removal rate of 223.6 nm h −1 is achieved with significantly reduced secondary pollution from dissolved iron ions. This study demonstrates the potential of the piezoelectric-Fenton synergistic strategy for ultra-precision machining and advanced polishing applications.