包覆型CeO_2/SiO_2和CeO_2/聚苯乙烯复合磨料的制备及其化学机械抛光性能

PREPARATION AND ITS OXIDE CHEMICAL MECHANICAL POLISHING PERFORMANCE OF CERIA-COATED SILICA AND CERIA-COATED POLYSTYRENE NANOPARTICLE

以SiO2和聚苯乙烯(polystyrene,PS)微球为内核,采用液相沉淀工艺制备了具有包覆结构的CeO2/SiO2和CeO2/PS复合颗粒。利用X射线衍射仪、透射电子显微镜、场发射扫描电子显微镜、X射线光电子能谱仪、动态光散射仪和zata电位测定等手段对所制备样品进行了表征。将所制备的CeO2/SiO2和CeO2/PS复合颗粒用于硅晶片热氧化层的化学机械抛光,用原子力显微镜(atomic force microscope,AFM)观察抛光表面的微观形貌、测量表面粗糙度。结果表明:所制备的CeO2/SiO2和CeO2/PS复合颗粒呈球形,粒径在150～200nm,CeO2纳米颗粒在SiO2和PS微球内核表面包覆均匀。包覆的CeO2颗粒与SiO2内核之间形成了化学键结合。CeO2颗粒的包覆显著的改变了复合颗粒的表面电性。AFM测量结果表明:经CeO2/SiO2和CeO2/PS复合磨料抛光后的硅热氧化片表面在5μm×5μm范围内粗糙度值分别为0.292nm和0.180nm。

SiO2 and polystyrene（PS） microspheres were directly coated with CeO2 by chemical precipitation technique.The as-prepared samples were analyzed by X-ray diffraction,transmission electron microscopy,field emission scanning electron micros-copy,X-ray photoelectron spectrometry,dynamic light scattering and zeta potential analysis.The chemical mechanical polishing performance of CeO2-coated SiO2 and CeO2-coated PS composite abrasives to thermal oxide film on Si wafer surface was investigated by atomic force microscopy.The results indicate that the successful preparation of spherical CeO2-coated SiO2 and CeO2-coated PS particles with particle sizes of 150-200 nm and core（SiO2/PS） uniformly coated by CeO2.The isoelectric point of the CeO2-coated SiO2 and CeO2-coated PS nanoparticles is about 6.2,5.9.CeO2 is chemically bound with SiO2,and as a result,Si-O-Ce is formed.The surface roughness values within a 5 μm × 5 μm area of the thermal oxide film polished by CeO2-coated SiO2 and CeO2-coated PS composite abrasives are 0.292 nm and 0.180 nm,respectively.