【作者】 王军；

【导师】 朱永伟；

【作者基本信息】 南京航空航天大学 ， 机械制造及其自动化， 2009， 硕士

【摘要】 化学机械抛光(CMP)是目前半导体制造中唯一能够实现全局平坦化的加工技术,它广泛应用于单晶硅衬底和金属互连层结构的层间平坦化等加工。然而,传统CMP技术还存在一定的缺点和局限性,如工艺稳定性差、效率低、成本高、环境污染严重等。固结磨料化学机械抛光技术应运而生,它能够从根本上解决游离磨料抛光工艺的不足,提高加工效率,改善加工工件的表面质量,减少废液处理压力,保护环境和降低生产成本。本文从固结磨料抛光垫制备着手,通过对抛光垫基体性能影响因素的分析,探索其对工件材料去除率以及加工后工件表面质量的影响,并获得高材料去除率和高加工精度的固结磨料抛光垫。本文主要工作和取得成果如下:1)提出了抛光垫基体特性(溶胀率、硬度)的评价方法,运用正交试验方法分析了各组分对基体特性的影响。结果表明:TMPTA对基体溶胀率与湿态硬度影响特别显著,PUA对基体湿态硬度影响特别显著。2)介绍了两种固结磨料抛光垫的制备方法,并对其抛光性能进行了比较研究。以2.5~5μm金刚石为磨粒,制备了八种固结磨料抛光垫对K9光学玻璃和硅片进行探索性抛光试验。结果表明:低的溶胀率有助于提高工件的材料去除率和降低加工后工件的表面粗糙度;较低的湿态硬度能够获得较低的表面粗糙度和高的材料去除率。3)采用特定溶胀率和湿态硬度的CeO2固结磨料抛光垫对硅片、手机面板玻璃以及K9光学玻璃进行抛光试验,并与传统游离磨料抛光工艺进行比较,结果表明:目前阶段,CeO2固结磨料抛光垫对硅片的材料去除率极低,对K9光学玻璃和手机面板玻璃的材料去除率亦不如游离磨料抛光,但表面质量要稍好。4)比较研究了金刚石固结磨料与游离磨料抛光硅片等材料,结果表明:5~10μm金刚石固结磨料抛光垫抛光硅片的材料去除率是游离磨料抛光的3倍,同时实现了自修整功能;固结磨料抛光对磨粒粒径大小的依赖没有游离磨料抛光那么强,采用2.5~5μm与5~10μm的金刚石磨料抛光,能够获得同样好的工件表面质量;并从加工后工件表面的划痕出发分析了两种抛光工艺的抛光特点。更多还原

【Abstract】 Chemical Mechanical Polishing (CMP) is the only technique capable of achieving high level of global planarization, and is widely used in manufacturing monocrystalline silicon wafer and the metal interconnection which is used in the multi-level wiring process. However, conventional CMP technology has some disadvantages and limitations, such as worse process stability, low-level efficiency, high cost and severe environmental pollution. Fixed-abrasive chemical mechanical polishing technology comes into being, which enables to resolve the defects of abrasive polishing process, raise efficiency, improve the surface quality of work pieces, reduce the pressure of liquid waste disposal, protect the environment and reduce production cost. The study commences on the preparation of fixed-abrasive polishing pad, seeks its influence on material removal rate as well as the processed surface quality through the analysis of the performance influencing factors on the polishing pad matrix, and gets fixed-abrasive polishing pad with high material removal rate and high machining accuracy.The main work and the achievements are as follows:1) The swelling rate and the hardness are selected as the evaluation criteria of the polishing pad matrix properties. The influence of each component on the characteristics of matrix is analyzed based on orthogonal test. It shows that the ratio of TMPTA influenced the swelling rate and the wet hardness particularly obvious, and the ratio of PUA influenced the wet hardness particularly obvious.2) The method of two kinds of polishing pad preparation is introduced, and their polished performances are compared. Choosing eight kinds of 2.5~5μm diamond fixed-abrasive polishing pad, the polishing experiments on the K9 optical glass and the silicon wafer are studied. The results show that lower swelling rate benefits to improve the material removal rate and reduces the processed surface roughness, and lower wet hardness benefit to get lower surface roughness value and higher material removal rate.3) Choosing ceria fixed-abrasive polishing pad with specific swelling rate and wet hardness, polishing experiments on silicon wafer, mobile phone panel glass and K9 optical glass are studied to compare with conventional abrasive polishing. At the present stage, the results show that ceria fixed-abrasive polishing pad has a extremely low material removal rate on the silicon wafer, and a lower material removal rate on K9 optical glass and mobile phone panel glass than abrasive polishing ,but better surface quality. 4) Studying the polishing of silicon wafer and other material by diamond fixed-abrasive polishing and abrasive polishing, it shows that the material removal rate of silicon wafer polished with 5~10μm diamond fixed-abrasive polishing pad is three times as much as that polished with conventional polishing and the function of self-conditioning is working on the process of fixed-abrasive polishing. The particle size plays a weaker role in fixed-abrasive polishing than abrasive polishing, so the work pieces could get the same good surface quality with 2.5~5μm and 5~10μm diamond abrasive. And the characteristic of the two polishing process is analyzed from the scratches of the processed work pieces surface.更多还原