(1. 常州大学 材料科学与工程学院,常州 213164;
2. 苏州科技学院 化学与生物工程学院,苏州 215011)
摘 要: 以经过聚乙烯吡咯烷酮(PVP)进行表面修饰的聚苯乙烯(PS)微球为内核,在碱性条件下采用溶胶-凝胶法在PS微球直接包覆SiO2,制备有机/无机PS/SiO2复合微球,通过控制反应体系中正硅酸乙酯(TOES)的浓度来控制复合微球中氧化硅的质量分数,并借助原子力显微镜(AFM)考察了PS/SiO2复合磨料对硅热氧化片的抛光特性,初步分析有机/无机复合磨料的非刚性力学特性对抛光质量的影响。透射电镜(TEM)结果显示:复合微球具有草莓状核壳包覆结构,其氧化硅壳层是由SiO2纳米颗粒所组成;热失重分析(TGA)表明:样品中氧化硅含量为12%~69%(质量分数)。AFM测试结果表明:复合磨料中氧化硅的含量对抛光后晶片的微观形貌、粗糙度及表面轮廓具有明显的影响。
关键字: 核壳结构;复合微球;磨料;聚苯乙烯;氧化硅
(1. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China;
2. Department of Chemistry and Bioengineering, Suzhou University of Science and Technology, Suzhou 215011, China)
Abstract:The polyvinylpyrrolidone (PVP) modified polystyrene (PS) microspheres were first synthesized by soap-free emulsion polymerization method, and the SiO2 nanoparticles were subsequently coated on the surfaces of the PS cores by sol-gel method in alkaline NH4OH/ethanol solutions. The silica content of composite microspheres can be controlled by adjusting the concentration of tetraethoxysilane (TEOS) in the reaction system. The oxide chemical mechanical polishing (CMP) behavior of as-prepared PS/SiO2 composite abrasives was investigated by atomic force microscopy (AFM). The effect of non-rigid mechanical property of organic/inorganic composite abrasives on the CMP behavior was also discussed. TEM results show that the composite microspheres exhibits core/shell structure with strawberry-like morphology, and the silica shell is composed by SiO2 nanoparticles. Thermogravimetric analysis (TGA) results indicate that the silica contents in the composite microspheres range from 12% to 69% (mass fraction). AFM tests results indicate that there is obvious effect of the silica content of the composite abrasives on the roughness values, topographies and profilograms of the polished wafer surfaces.
Key words: core/shell structure; composite microsphere; abrasive; polystyrene; silica