Study on material removal mechanism of solid phase Fenton catalytic polishing of SiC wafer with gel-forming abrasive disc

Single crystal silicon carbide (SiC) is an important wide bandgap semiconductor material widely used in multiple fields. High surface quality processing of SiC is a prerequisite for the performance of SiC electronic components to be fully utilized. Due to the hardness, brittleness and chemical inertness of SiC, traditional free abrasive machining has difficulty in balancing machining quality and efficiency. Therefore, a new gel-forming abrasive disc containing GO/Fe₃O₄ (G/F) solid phase catalyst was prepared. The solid phase catalyst in the gel-forming abrasive disc could react with SiC in the polishing process to soften the workpiece surface, and the fixed abrasive in the gel-forming abrasive disc could realize micro edge cutting of the modified layer on the surface of the workpiece. In this study, the influence of G/F on the polishing performance of the gel-forming abrasive disc was systematically investigated. XPS, SEM, and TEM were used to observe the surface morphology and elemental changes of the workpiece and the gel-forming abrasive disc, and the chemical reaction and removal mechanism between SiC and gel-forming abrasive disc during the polishing process were analyzed. The optimal experimental parameters were determined through orthogonal experiments. These results indicate that chemical bonds on the surface of the part dissociate and rebuild during polishing. Furthermore, the hardness of the formed reaction layer is significantly lower than that of the abrasive, resulting in a significant increase in removal rate. The surface roughness (S_a) can be reduced from 120 nm to 2.2 nm after rough polishing, while the material removal rate of the gel-forming abrasive disc containing G/F achieves 1.65 μm/h, which is 70.1 % higher than that of the gel-forming abrasive disc without containing G/F. These results indicate that gel-forming abrasive disc with Fenton catalytic ability provide an effective polishing method for achieving high surface quality in SiC wafer.