Investigation on Electrical Enhanced Photocatalysis Polishing of Single-Crystal Silicon Carbide Substrates

In order to solve the problems of low efficiency, pollution and large damage of existing polishing methods, the electrical enhanced photocatalysis polishing method for single-crystal silicon carbide was proposed in this paper. The recombination of electrons and holes was inhibited by the combined action of applied electric field and chemical trapping agent, so the efficiency of oxidation was improved, and the polishing of silicon carbide with high efficiency and low damage can be achieved. The effects of various parameters such as polishing pressure, polishing speed, polishing pad, abrasive particles and oxygenation of slurry on polishing effect were studied. 0.025 MPa of polishing pressure, 60 r/min of polishing speed, 5 wt% of SiO 2 abrasive particles and synthetic fiber polymer polishing pad can provide the higher MRR of 1.18 μm/h and the best surface quality (Ra = 0.348 nm). In addition, it has been proven that UV, optimized pH, types of photocatalysts, electron trapping agent and voltage are necessary factors for the slurry to exhibit strong oxidizing properties. The MRR is mainly determined by both mechanical action (introduced by abrasive particles) and chemical action (introduced by slurry). The above technology can basically meet the requirements of high-efficiency, ultra-smooth and low damage polishing of single-crystal silicon carbide.