Mn oxide synergistic 4H-SiC chemical mechanical polishing solution based on KMnO4-Al2O3 system

The invention relates to a Mn oxide synergistic 4H-SiC chemical mechanical polishing solution based on a KMnO4-Al2O3 system and a preparation method of the Mn oxide synergistic 4H-SiC chemical mechanical polishing solution. The polishing solution comprises an oxidizing agent KMnO4, Al2O3 abrasive particles, Mn oxide, a pH regulator and deionized water. Wherein the concentration of the oxidizing agent KMnO4 is 0.01 mol/L to 0.1 mol/L, the concentration of the Al2O3 abrasive particles is 0.01 wt.% to 10 wt.%, the particle size of the Al2O3 abrasive particles is 100 nm to 500 nm, the concentration of the Mn oxide is 0.01 wt.% to 1 wt.%, and the pH value of the 4H-SiC polishing solution is 7 to 11. And the Mn oxide is one or more of MnO2, Mn2O3 and Mn3O4. The invention further discloses a preparation method of the catalyst. The problems that a traditional silicon carbide polishing solution is low in 4H-SiC wafer surface material removal rate, poor in polished surface quality and serious in equipment corrosion are