Study on the photocatalytic performance of photocatalytic fixed polishing plate and its effect on the polishing performance of single-crystal SiC

To efficiently polish single-crystal silicon carbide (SiC), an Ultraviolet photocatalytic (UV-PC) fixed polishing plate containing TiO 2 was developed. The influence of UV-PC parameters on the concentration of hydroxyl radicals (·OH) and the polishing performance of SiC was studied. The influence of photocatalytic parameters, including TiO 2 mass fraction, H 2 O 2 mass fraction, and light intensity, on the concentration of ·OH was investigated using a spectrophotometric system. Based on this, the polishing experiment was conducted on single-crystal SiC. Results show that material removal rate (MRR) and ·OH concentration were significantly correlated. As the mass fraction of TiO 2 , mass fraction of H 2 O 2 , and light intensity increase, the concentration of ·OH radicals initially rises before declining, while the MRR of SiC initially increases before decreasing. Conversely, the surface roughness Ra of SiC exhibits first decreases before increasing. Under the conditions of 10 wt% TiO 2 , 10 wt% H 2 O 2 , and light intensity of 40 mW/cm 2 , the concentration of ·OH was highest, leading to the most significant fading of the methyl orange (MO) solution. Within 40 min, the degradation rate of the MO solution reached 99.3 %. At this time, the MRR of SiC was highest, reaching 4.05 μm/h, and the surface roughness Ra was lowest, at 1.09 nm. Compared to conventional methods without UV-PC processing, the MRR of SiC processed by UV-PC fixed polishing plate is significantly increased by 73.1 %, and peak-valley (PV) value and surface roughness are reduced by 58.1 % and 45.8 %, respectively. These research findings offer essential reference values for developing visible light-assisted SiC chemical mechanical polishing technology.