Chemical-Mechanical Polishing of 4H Silicon Carbide Wafers

4H silicon carbide (4H-SiC) holds great promise for high-power and high-frequency electronics, in which high-quality 4H-SiC wafers with both global and local planarization are cornerstones. Chemical-mechanical polishing (CMP) is the key processing technology in the planarization of 4H-SiC wafers. Enhancing the performance of CMP is critical to improving the surface quality and reducing the processing cost of 4H-SiC wafers. In this review, the superior properties of 4H-SiC and the processing of 4H-SiC wafers are introduced. The development of CMP with chemical, mechanical, and chemical-mechanical synergistic approaches to improve the performance of CMP is systematically reviewed. The basic principle and processing system of each improvement approach are presented. By comparing the material removal rate of CMP and the surface roughness of CMP-treated 4H-SiC wafers, the prospect on the chemical, mechanical, and chemical-mechanical synergistic improvement approaches is finally provided.