内核尺寸对核/壳结构PS/SiO_2复合磨料抛光特性的影响  

Effect of the core size of the core /shell structured PS /SiO_2 composite abrasives on oxide-CMP behavior

作　　者：陈杨[1,2] 李志娜[2] 宋志棠[1,3] 闵国全 

机构地区：[1]上海市纳米科技与产业发展促进中心,上海200237 [2]常州大学材料科学与工程学院,江苏常州213164 [3]中科院上海微系统与信息技术研究所,上海200050

出　　处：《功能材料》2014年第19期19121-19127,共7页Journal of Functional Materials

基　　金：上海市自然科学基金资助项目(13ZR1436700);中国博士后科学基金资助项目(2013M541535)

摘　　要：核/壳结构有机/无机复合微球作为一种新型抛光介质,在实现高效无损伤抛光方面具有重要的应用价值.以无皂乳液聚合法制备的聚苯乙烯（PS）为内核,通过溶胶-凝胶法合成了一系列具有不同内核尺寸的 PS/SiO 2复合微球.利用 FT-IR、FESEM 和TEM 等手段对样品进行表征,并借助 AFM 考察了复合磨料内核尺寸对 SiO 2介质层抛光质量的影响规律.结果表明,所制备单分散 PS 微球尺寸在200～600 nm,复合微球的壳层由 SiO 2纳米颗粒（5～10 nm）所组成,壳厚在10～15 nm.材料去除率（MRR）随复合磨料内核尺寸的减小而降低,而抛光后晶片表面粗糙度（RMS）的变化则不明显.当复合磨料内核尺寸为210 nm 时,抛光后 RMS 和 MRR 分别为0．217 nm 和126．2 nm/min.提出将核壳结构有机/无机复合磨料理解成一种表面布满无机纳米颗粒的微型“抛光垫”,尝试用有效磨料数量以及壳层中单个 SiO 2颗粒的压入深度对 CMP 实验结果进行解释,并进一步讨论了有机内核在抛光过程中的作用.Core/shell organic/inorganic composite microspheres as novel abrasives have an important application in efficient and damage-free polishing due to their uniform non-rigid mechanical properties.A series of polysty-rene (PS)microspheres with various sizes were synthesized by surfactant-free emulsion polymerization method and then coated with silica nanoparticles by sol-gel process to obtain the core/shell structured PS/SiO 2 compos-ites.The as-synthesized samples were characterized by FT-IR,FESEM and TEM technique.The effect of the core size of the PS/SiO 2 composite abrasives on oxide-CMP behavior were investigated by AFM.The results in-dicated that the size of the obtained PS microspheres ranged from 200 to 600 nm.The shells of the composites were composed of SiO 2 nanoparticles (5-10 nm),and the shell thickness was 10-15 nm.After CMP,with the decrease of the core size,the material removal rate (MRR)was decreasing,while the root mean square (RMS) of the wafer surface almost retain constant.For the composite of the core size of 210 nm,the RMS and MRR values were 0.217 nm and 126.2 nm/min,respectively.We proposed that the core/shell organic/inorganic com-posites could be considered as micro-polishing pads,which were covered with inorganic nanoparticles.The mod-el used to explain the results take into account both the total number of active abrasives and the indentation depth of single SiO 2 particle onto the wafer surface,and the effect of the PS cores on the behavior of composite abrasives was also discussed.

关 键 词：聚苯乙烯 氧化硅 包覆结构 复合磨料 化学机械抛光 

分 类 号：TB383[一般工业技术—材料科学与工程]