Processing properties for the Si-face of the 4H-SiC substrates using the magnetically-controlled abrasive solidification orientation–solid-phase Fenton reaction for the fabrication of the lapping–polishing plate

Abstract A combination of the magnetically-controlled abrasive solidification orientation and solid-phase Fenton reaction was used to fabricate new lapping–polishing plates to improve the ultra-precision processing efficiency and the surface quality of the single-crystal 4H-SiC substrates. The effect of abrasive orientation, solid-phase Fenton reaction and their synergistic effect on the Si-face of 4H-SiC during the lapping–polishing process was analyzed and verified by conducting experiments. The effect of abrasive to Fe3O4 concentration ratios and the abrasive types used on the processing effect was also studied to modify the plate components. The material removal rate (MRR) increased by 111.12%, 100.00%, and 144.55% (compared to the MRR achieved under conditions of the abrasive random distribution removal effect) under the effect of the abrasive orientation, solid-phase Fenton reaction, and their synergistic effect, respectively. The surface roughness (Ra) was reduced by 46.02%, 14.17, and 54.29%, respectively. Furthermore, the abrasive random distribution effect, the abrasive orientation effect, and the synergistic effects of the solid-phase Fenton reaction and abrasive orientation (MRRc-m-d) contributed 40.89%, 45.47%, and 13.64% to the substrate MRR. The MRR was as high as 52.316 nm/min, and the Ra reduced from 99.95 nm to Ra 0.91 nm when the Si-face was processed for 60 min using a lapping–polishing plate prepared in the presence of a magnetic field of intensity 60 mT, an abrasive of diamond, and an abrasive to Fe3O4 concentration ratio of 1:5. Compared with the unmodified lapping-polishing plate, the MRRc-m-d increased 62.90% to MRR, MRR increased 104.54%, and surface quality improved by 79.41%. The results revealed that an improvement in the MRRc-m-d effect resulted in a significant increase in MRR while improving the surface quality. This method can be potentially used to achieve the lapping–polishing of SiC substrates and other optoelectronic substrates.