【作者】 张然；

【导师】 金洙吉；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2007， 硕士

【摘要】 随着集成电路(IC)特征线宽微细化进程的加快，光刻焦深变得越来越短，对IC芯片表面平整度的要求也越来越苛刻，加之硅片直径的增大和金属布线层数的不断增加，给化学机械平坦化(chemical mechanical planarization，CMP)技术带来了前所未有的挑战。虽然CMP技术被认为是目前可以兼顾IC芯片全局和局部平整度要求的、最实用的超大规模集成电路(ULSI)铜互连层平坦化方法，但由于铜CMP抛光机理极为复杂，仍然存在工艺稳定性差、成品率和生产率较低等问题。在CMP过程中，铜CMP抛光液对被加工表面具有化学腐蚀和机械研磨的双重作用，对抛光效果有着重要影响，目前仍存在诸如金属离子污染、分散性差、碱性环境下材料去除率低等问题。深入研究铜CMP材料去除机理以及研究和开发更高性能抛光液是解决上述问题的有效途径，也是当前CMP技术领域的研究热点。本文以ULSI铜互连层CMP抛光液配方为研究方向，在介绍、分析抛光液的材料去除原理和特点以及总结已有研究成果的基础上，将研究定位于碱性铜抛光液，以提高抛光液的材料去除率、降低抛光液中金属离子含量和提高抛光质量为目标，进行了抛光液配方选择和优化方面的研究，找到了较好的抛光液成分和配方，研制出了性能良好的碱性铜抛光液。本文的研究思路为：首先通过对铜CMP机理的研究，找到影响抛光质量的主要因素，并结合当前铜抛光液存在的一些主要问题制定抛光液成分选择和配方优化的试验方案。然后，讨论了抛光液各成分的作用原理，以UNIPOL1502型研磨抛光机和CETR公司CP-4型抛光机为试验平台，进行了抛光液成分选择的单因素试验，通过试验选出了较适合ULSI铜互连层抛光的纳米磨料、氧化剂、有机碱、表面活性剂和分散剂等主要成分。接着，以单因素试验选出的主要成分为基础，又进行了复配次序优化、工艺参数和组分优化等试验，得到了抛光效率较高，性能良好的碱性铜抛光液。研究成果为提高碱性铜抛光液的抛光质量、材料去除率以及改善抛光液性能，提供了比较系统的研究方法和丰富的试验结论，对进一步完善ULSI铜互连层平坦化技术具有重要指导意义。更多还原

【Abstract】 Along with the feature size of IC becoming smaller and smaller, the depth of focus of photoetching technique is becoming shorter and shorter. The requirements to surface flatness also turn to more rigorous than before. The increasing of silicon wafer diameter and layers of multi-level metal interconnects bring CMP technology an unprecedented challenge. Although the CMP technology is considered as the most applied and irreplaceable method for realizing local and global planarization during the manufacturing process of IC, but because the complexity of copper CMP mechanism, there are still some problems such as worse technique stability, low rate of finished products and productivity. In the process of CMP, the copper CMP slurry make a dual function of chemical erosion and mechanical lapping, have an important influence to the surface quality. Now, copper CMP slurry still has the problems of metal ion contamination, low material removal rate in alkalescent environment and so on. Studying the material removal mechanism thoroughly of copper CMP and developing high performance CMP slurry, as two doable approaches to resolve problems that mentioned above, has become the researching focuses in the CMP technology field recently.The subject of this paper is the study of slurry prescription suitable for copper interconnection layer in ULSI manufacturing. For reducing metal ions content, improving material removal rate, the selection of slurry prescription and optimization is studied through many theories and experiments. Meanwhile, the material removal mechanism has also been discussed. At last, the ingredients and prescription of slurry is found, and the slurry is made with well properties.The researching route of this paper is: Firstly, the CMP mechanism has been studied in this paper. The factors that influence the polishing quality mostly have been found. At the same time after considering the main problems of copper slurry at present, the projects of selecting ingredients and optimizing prescription have been established. Secondly, the functions of main ingredients of slurry have been analyzed. The single factor experiments of every ingredients of slurry have been carried out on the UNIPOL1502 lapping polishing machine and CP-4 polishing machine. Through the experiment, the main ingredients of slurry, such as abrasive, organic alkali, oxidant etc, have been selected that suitable for the copper polishing. Lastly, on the basis of research before, the optimization experiments of parameters and ingredients have been carried out, finally got a sort of high efficiency and high performance alkalescent copper slurry.The study of this paper provides a kind of systemic researching methods and a group of useful experimental conclusions for improving the polishing quality of alkalescent copper slurry, increasing the material removal rate and how to optimize the slurry description. It has significant meaning for developing the metal interconnection layer planarization technology for Ultra Large Scale Integrate Circuit.更多还原