Preparation of homogeneous sub-micron cerium oxide polishing powder

To obtain homogeneous submicron cerium dioxide (CeO₂) polishing powder, CeO₂ was synthesized by solvothermal reaction using cerium nitrate (Ce(NO₃)₃·6H₂O) as cerium resource and alcohol-water mixed solution as solvent. The phase composition and morphology of CeO₂ were characterized by X-ray diffraction (XRD), laser particle size analyzer and scanning electron microscope (SEM). The formation process of CeO₂ particles was analyzed by changing the concentration of Ce³⁺ and alcohol-water ratio. The synthesized CeO₂ was used for chemical mechanical polishing (CMP) Si-face of 6H-SiC. The polishing characteristics were tracked by atomic force microscopy (AFM) and electronic balance. The results indicates that when the Ce³⁺ concentration is 0.10 mol/L and alcohol/water volume ratio is 3∶1, the as-prepared particles have regular morphology, moderate particle size and uniform particle size distribution. After polished by using the as-prepared CeO₂, the R_a of wafer surface reached 0.243 nm and the d_MRR 287 nm/h. The as-prepared CeO₂ can be used for chemical mechanical polishing.