Study on the Mechanism of Solid-Phase Oxidant Action in Tribochemical Mechanical Polishing of SiC Single Crystal Substrate

Wanting Qi; Xiaojun Cao; Wen Xiao; Zhankui Wang; Jianxiu Su

doi:10.3390/mi12121547

Study on the Mechanism of Solid-Phase Oxidant Action in Tribochemical Mechanical Polishing of SiC Single Crystal Substrate

Micromachines (Basel). 2021 Dec 12;12(12):1547. doi: 10.3390/mi12121547.

Authors

Wanting Qi¹, Xiaojun Cao¹, Wen Xiao¹, Zhankui Wang¹, Jianxiu Su¹

Affiliation

¹ School of Mechanical and Electrical Engineering, Henan Institute of Science and Technology, Xinxiang 453003, China.

Abstract

Na₂CO₃-1.5 H₂O₂, KClO₃, KMnO₄, KIO₃, and NaOH were selected for dry polishing tests with a 6H-SiC single crystal substrate on a polyurethane polishing pad. The research results showed that all the solid-phase oxidants, except NaOH, could decompose to produce oxygen under the frictional action. After polishing with the five solid-phase oxidants, oxygen was found on the surface of SiC, indicating that all five solid-phase oxidants can have complex tribochemical reactions with SiC. Their reaction products are mainly SiO₂ and (SiO₂)x. Under the action of friction, due to the high flash point temperature of the polishing interface, the oxygen generated by the decomposition of the solid-phase oxidant could oxidize the surface of SiC and generate a SiO₂ oxide layer on the surface of SiC. On the other hand, SiC reacted with H₂O and generated a SiO₂ oxide layer on the surface of SiC. After polishing with NaOH, the SiO₂ oxide layer and soluble Na₂SiO₃ could be generated on the SiC surface; therefore, the surface material removal rate (MRR) was the highest, and the surface roughness was the largest, after polishing. The lowest MRR was achieved after the dry polishing of SiC with KClO₃.

Keywords: 6H-SiC; dry polishing; fixed abrasive; solid-phase oxidant; tribochemical mechanical polishing.