In order to improve the material removal rate(MRR) and improve the surface quality of 6H-SiC wafer,the photoFenton reaction system was used for chemical mechanical polishing (CMP) of 6H-SiC wafer.The influences of ultraviolet light intensity,pH values of slurry,H2O2 mass fraction and Fe2+ concentration on the polishing effects of 6H-SiC wafer were examined.The surface morphology of the 6H-SiC wafer were observed with atomic force microscope(AFM).The particle size distribution and Zeta potential of SiO2 abrasive particles in the slurry were measured with nanoscale potentiometer.The concentration of hydroxyl radical (·OH) in the solution were detected with visible spectrophotometry and the mechanism of ultraviolet light was analyzed by UV-visible spectroscopy.The results indicate that the MRR of 6H-SiC is increased with the introduction of ultraviolet light,and the MRR is gradually increased with the increasing of the ultraviolet light power.With the increasing of pH values,H2O2 mass fraction and Fe2+ concentration,the MRR of 6H-SiC is increased firstly and then decreased.The pH values affect the electrostatic repulsion between the abrasive grains and the dispersion stability of the abrasive grains,thereby affecting the MRR of 6H-SiC.Compared with the polishing solution using the Fenton reaction system,the polishing solution using the photoFenton reaction system produces much more hydroxyl radica,indicating that ultraviolet light can increase the amount of hydroxyl radica in the reaction system,thereby promoting the surface oxidation of SiC wafer,increasing the MRR of 6H-SiC and improving its surface quality