Influence of Cerium Oxide Abrasive Particle Morphologies on Polishing Performance

In this study, two morphologies of cerium oxide (CeO₂) abrasive particles, octahedral and spheroidal, are synthesized by solvothermal method using cerium nitrate hexahydrate (Ce(NO₃)₃-6H₂O) as raw material. Fourier infrared spectroscopy, X-ray diffractometer (XRD) and scanning electron microscopy (SEM) are used to characterize the composition and morphology of CeO₂ abrasive particles. The synthesized CeO₂ is used for chemical mechanical polishing (CMP) of the Si surface of 6H-SiC wafers, and the surface morphology of the polished wafers are observed using atomic force microscopy (AFM). After polishing with octahedral and spheroidal abrasive particles, the surface roughness of the wafers are 0.327 and 0.287 nm, and the material removal rates (MRR) are 870 and 742 nm h⁻¹, respectively. Calculations comparing the ultraviolet absorption spectra and bandgap energies of the two types of abrasive particles as well as molecular dynamics (MD) simulations reveal that the synthesized octahedral CeO₂ particles possessed stronger surface chemical activity and material removal performance.