Preparation and processing properties of magnetically controlled abrasive solidification orientation—solid-phase Fenton reaction lapping-polishing plate for single-crystal 4H-SiC

Abstract

To improve the ultraprecision processing efficiency and surface quality of single-crystal 4H-SiC substrates, a lapping-polishing plate combining magnetically controlled abrasive solidification orientation and a solid-phase Fenton reaction was prepared. Furthermore, the effects of the concentration ratio of abrasive to Fe3O4 and abrasive types on the physical properties of the lapping-polishing plate and the processing properties for single-crystal 4H-SiC substrates were studied to reveal the lapping-polishing mechanism of magnetically controlled abrasive solidification orientation—solid-phase Fenton reaction. The results show that the concentration ratio of abrasive to Fe3O4 and abrasive types affects the distribution of the magnetic chain string structure and the distribution of abrasive materials, affecting the plate's processing properties. The higher the abrasive concentration is, the higher the material removal rate (MRR), but it affects the abrasive orientation and the solid-phase Fenton reaction. In contrast, the high Fe3O4 concentration strengthens the solid-phase Fenton reaction and weakens the mechanical removal of the abrasive, resulting in low MRR and poor processing quality. When the abrasive and the concentration ratio of abrasive to Fe3O4 are diamond and 1:5, the MRR is the largest (46.5 nm/min), and a smooth surface with a surface roughness Ra of 0.89 nm can be obtained. The magnetically controlled abrasive solidification orientation—solid-phase Fenton reaction lapping-polishing process—is a chemical reaction and mechanical removal process. The chemical reaction can promote MRR and improve the lapping-polishing quality while affecting the lapping-polishing plate's surface microstructure and processing properties. The dynamic equilibrium between the material removal process of SiC substrates and the wear of lapping-polishing plates enable high-efficiency, high-quality and low-damage processing of SiC substrates. This method and plates can be potentially used to achieve the fine lapping and polishing of SiC substrates and other optoelectronic substrates.