The polishing properties of magnetorheological-elastomer polishing pad based on the heterogeneous Fenton reaction of single-crystal SiC

Abstract

Magnetic particles (Fe3O4/CIP) in magnetorheological elastomer (MRE) were used as solid-phase catalysts in the heterogeneous Fenton reaction for chemical mechanical polishing (CMP) of single-crystal SiC. The polishing effect and polishing mechanism were investigated by experiments and polishing debris analysis. The results show that when using H2O2 polishing solution the material removal rate (MRR) was higher and the surface roughness (Ra) was lower at all stages of polishing than using deionized water polishing solution. The MRRs when polishing for 60 min with the deionized water and the H2O2 polishing debris were, respectively, 636.94 nm/h and 1194.27 nm/h (an increase by 87.5%), and the corresponding Ra values were, respectively, 12.445 nm and 4.420 nm (a decrease by 64.5%). From the analysis of the polishing debris after 60 min of polishing, it was found that the H2O2 polishing solution was polished with laminated loose chips, and the main elements of the chips were C, O, and Si, with O element accounting for 38.585 wt%. This indicates that a chemical reaction has occurred on the SiC surface during polishing, generating low hardness and low binding strength SiO2, and thus resulting in increased material removal; this phenomenon is confirmed by the profile morphology of SiC wafer by fixed-point polishing. It is shown that the use of Fe3O4/CIP in MRE as a solid-phase catalyst for the heterogeneous Fenton reaction of polishing SiC can substantially increase the material removal capacity of MRE polishing pads and improve the polishing quality at the same time.