均一亚微米级氧化铈抛光粉的制备

为得到均一的亚微米级二氧化铈（CeO₂）抛光粉，以六水合硝酸铈（Ce(NO₃)₃·6H₂O）为原料，以醇－水混合溶液为溶剂，采用溶剂热法合成CeO₂。改变Ce3+浓度和醇-水体积比，利用X射线衍射仪（XRD）、激光粒度分布仪、扫描电子显微镜（SEM）对CeO₂的物相组成和形貌特征进行表征，分析CeO₂粒子的形成过程。将合成的CeO₂用于6H-SiC晶片Si面的化学机械抛光（chemical mechanical polishing，CMP），利用原子力显微镜（atomic force microscopy, AFM）和电子天平得出CeO₂的抛光性能。结果表明:Ce3+浓度为0.10 mol/L，醇－水体积比为3∶1时合成的CeO₂的形貌规则、晶粒尺寸适中且粒度分布均匀。采用其抛光后，晶片表面粗糙度R_a为0.243 nm，材料去除速率d_MRR为287 nm/h。合成的CeO₂适用于化学机械抛光。 

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.