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题名	纳米氧化铈抛光粉的合成与性能研究
作者	姚生永
学位类别	硕士
答辩日期	2008-05-18
授予单位	中国科学院过程工程研究所
授予地点	过程工程研究所
导师	卢旭晨
关键词	纳米氧化铈 化学机械抛光 溶胶-溶剂热法
其他题名	Synthesis of nano-sized ceria abrasive and its application in chemical-mechanical planarization (CMP)
学位专业	化学工程
中文摘要	稀土抛光粉尤其是氧化铈抛光粉是目前高精密光学玻璃、超薄液晶显示玻璃基板和半导体工业中超大规模集成电路基板抛光的主要打磨材料。氧化铈抛光粉的性能与粉体的颗粒大小、形貌、化学组成、煅烧温度等有很大的关系，因此控制制备工艺是得到高质量氧化铈抛光粉的前提条件。本论文以不同极性的有机溶剂为介质，研究了两种简单而有效地制备高质量纳米CeO2晶粉体的方法，对合成粉体进行光学玻璃精密抛光表征，并研究基于抛光粉颗粒的化学机械抛光机理。 首先在不同极性的有机溶剂中用直接加热沉淀法合成了纳米CeO2粉体，并得到了优化的实验条件参数。实验发现，产物CeO2纳米粉体的粒度基本都呈球状颗粒；溶剂的极性越小，偶极矩越小，介电常数ε越小，则生成的晶核尺寸就越小，团聚程度亦越轻。 其次，提出了一种制备粒度均一、团聚程度小的纳米晶粉体的方法——溶胶-溶剂热（SST）法，通过合成工艺条件的合理优化，可用于合成各类化合物如金属单质（如Ag和Cu）、氧化物（如CeO2，TiO2，Fe2O3、ZnO、CoFe2O4和BaTiO3）以及非氧化物（如ZnS和ZnSe）等近单分散的纳米晶粉体(10~50 nm)及其不同形貌（如线状、棒状、多面体和微球形）的自组装体。SST法合成的CeO2纳米晶粉体在适宜的煅烧温度下进行活化处理后，表现出了优异的精密抛光性能，与两款商业化的进口抛光粉不相上下。 在抛光液中引入还原态或氧化态试剂后发现，当抛光液中加入如Ce(NO3)3或N2H4等亲核试剂时，其抛光结果要明显的好于加入如(NH4)2Ce(NO3)6或NaClO等亲电试剂时的情况，说明了抛光粉颗粒表面CeIII态位的存在能够促进抛光速率，但也有赖于CeIII→CeIV态的转变速率。据此还提出了在抛光过程中化学抛光的化学键形成-断裂机理的新观点。 通过对抛光粉颗粒受力分析和模型简化，并基于机械抛光项和化学抛光项的线性关系假定，得到了小粒径、稀抛光液浓度时基于抛光粉颗粒的总抛光速率表示式。最后，通过分析不同阳离子掺杂的氧化铈粉体的抛光实验结果，用改进差分进化算法全局优化回归分析，得到最佳拟合曲线。
英文摘要	Rare earths, especially ceria polishing abrasives are the main polishing materials in the field of high-precision chemical-mechanical planarization (CMP) of optical glasses, super thin Liquid Crystal Display (LCD) as well as ultra-large integrated circuit substrates. However, the performances of ceria abrasives are deeply dependent on their particle diameter, morphology, chemical composition, and calcination temperatures. Hence, choosing appropriate synthetic methodology and technology is the the prerequisite to obtain high grade ceria abrasives. In this dissertation, two simple and effective methods are developed to synthesize ultra-fine ceria nanoparticles, using different organic solvents as the reaction media. Then the polishing efficiency of synthesized powders is characterized by performing on the high precision polishing of optical glasses. Finally, the CMP mechanism is studied based on the abrasive itself via introducing chemical routes. First of all, ceria nanoparticles are synthesized by direct precipitation method, using different polar organic solvents. In the meanwhile, the synthetic conditions are optimized by carefully control the experimental parameters. It is found that almost all of the prepared ceria powders are spheres and the particle diameter as well as the agglomeration state are both mainly related to the polarity of liquid environment where are powders are synthesized. The less polar of the solvents, i.e. the less dipole moment and dielectric constant ε, the smaller the generated nuclei are, also the weaker agglomeration condition of the powders is. Another general methodology, named sol-solvothermal (SST) strategy, is well developed for synthesis of monodisperse and weakly agglomerated nanocrystal powders. Through optimization of synthetic condition, it is facile for syntheses of nearly monodisperse inorganic nanocrystals (10~50 nm), such as elementary metals (such as Ag, and Cu), metal oxides (such as CeO2, TiO2, Fe2O3, ZnO, CoFe2O4, and BaTiO3), and non-oxides (such as ZnS, and ZnSe) as well as their different morphologies (such as wire, rod, polyhedral, and micro-spheres) of close-packed nanocrystal assemblies. The synthesized ceria nanopowders perform good high precision polishing efficiency after subjected to appropriate calcination temperatures compared to two other import commercial abrasives. Experiment results reveal that adding nucleophilic reagents such as Ce(NO3)3 or N2H4 into the polishing slurries can promote the polishing efficiency while adding the electrophilic reagents such as (NH4)2Ce(NO3)6 or NaClO are not. It is demonstrated that the existence of CeIII sites on the surface of abrasives can accelerate polishing rate which is, however, also dependent on the transition rate of CeIII→CeIV. In addition, several new points about the form/break mechanism of chemical bond during the CMP process are put forward. By analysis of stress on the abrasives and model simplification, a total polishing rate equation is induced under the conditions of small particle size and diluted polishing slurry, based on the liner hypothesis between the mechanical polishing item and chemical polishing item. Finally, a global optimal fitted curve is obtained by using an improved differential evolution arithmetic, which is based on the polishing results of different cation doped ceria nanoparticles.
语种	中文
公开日期	2013-09-13
页码	134
内容类型	学位论文
源URL	[http://ir.ipe.ac.cn/handle/122111/1205]
专题	过程工程研究所_研究所（批量导入）
推荐引用方式 GB/T 7714	姚生永. 纳米氧化铈抛光粉的合成与性能研究[D]. 过程工程研究所. 中国科学院过程工程研究所. 2008.

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