Photocatalytic assisted chemical mechanical polishing for silicon carbide using developed ceria coated diamond core-shell abrasives

The practical application of current photocatalytic-assisted chemical mechanical polishing (PCMP) technology still faces some challenges and difficulties, such as complex preparation process of abrasives, chemical failure, and the use of toxic chemicals. Herein, novel CeO2-coated diamond core/shell structure abrasives were successfully synthesized using a chemical precipitation method and applied in SiC-PCMP. After coating CeO2 on the surface of the diamond, the materials removal rate (MRR) was 56% higher than that of the diamond abrasives. With ultraviolet (UV) irradiation, the MRR of CeO2/diamond abrasives (11.5 nm/min) increased by about 195% compared with CeO2/diamond composite abrasives without UV. High surface quality (Ra: 0.4 nm) of the SiC substrate was obtained under UV light irradiation. The materials removal mechanism of SiC-PCMP was proposed.