【作者】 杨卫平；

【导师】 徐家文；

【作者基本信息】 南京航空航天大学 ， 机械制造及其自动化， 2008， 博士

【摘要】 在深入分析国内外化学机械抛光和超声加工技术研究现状的基础上,针对硅片传统化学机械抛光技术现状及其存在问题,特别是随着硅片直径不断增大,硅片抛光表面质量和抛光效率成为一个亟待解决和提高的问题,提出了超声椭圆振动—化学机械复合抛光硅片新技术的研究课题。该复合抛光技术是将超声加工和化学机械抛光加工综合为一体的新型加工技术,它在传统化学机械抛光基础上,将超声椭圆振动施加在抛光工具上,利用抛光工具产生的超声椭圆振动,提高了化学机械抛光中所使用抛光液的效能,达到改善抛光效果的目的。本文通过试验研究与理论分析相结合的方法,对复合抛光加工机理与工艺进行了深入研究,其主要研究内容及创新点包括:1.介绍了抛光工具超声椭圆振动产生的工作原理,推导了抛光工具超声椭圆运动的理论模型。研制了用于硅片表面及其边缘抛光的抛光工具,并实际测试了抛光工具的频率-阻抗特性和椭圆运动特性。2.研制了能够实现传统化学机械抛光,抛光工具做超声纵向振动、超声切向振动和超声椭圆振动等不同振动方式的复合抛光方法的试验系统。3.基于化学机械抛光和超声振动加工技术,进行了复合抛光加工机理研究。应用接触力学理论,建立了硅片表面与抛光垫之间的接触力学模型。在系统地研究化学机械抛光中各主要输入参数对加工表面质量影响的基础上,建立了简单实用的复合抛光材料去除率理论模型。对抛光工具做超声纵向振动、超声切向振动和超声椭圆振动等三种复合抛光方法,进行了材料去除机理及加工表面质量的理论研究,结果显示抛光工具的超声椭圆振动更有利于硅片综合抛光效果的改善。4.研究了一种在不破坏被加工件表面的情况下,对硅片等硬脆性材料微小去除量进行简易、快速的测量方法。5.进行了抛光工具的超声性能、抛光压力、抛光速度、抛光液供给量和抛光垫等,对硅片表面形貌、表面粗糙度和材料去除率等抛光试验研究。6.研究的超声椭圆振动—化学机械复合抛光方法的工艺规律表明,在相同的抛光条件下,复合抛光技术与传统化学机械抛光技术相比,抛光表面质量明显提高,材料去除率有较大增加,并且引入的描述抛光表面质量的不平整率KR也得到明显改善。总之,复合抛光方法相对于传统的化学机械抛光,无论在保证硅片抛光表面质量还是材料去除率等方面都有了一定的提高,为丰富超精密加工理论、提高硬脆性材料的超精密加工技术等具有重要的理论意义和工程应用价值。更多还原

【Abstract】 On the basis of analyzing the present situation of chemical mechanical polishing (CMP) and ultrasonic machining (USM) at home and aboard, according to technical status and existing problems of traditional CMP, especially for the diameter of silicon wafer increasing, constantly, the surface quality and efficiency of silicon wafer polishing are becoming an urgent problem to be solved and improved, so the research subject of ultrasonic elliptic vibration chemical-mechanical hybrid polishing(UEVCMHP) new technique is proposed. The compound polishing technique is novel processing technique that ultrasonic processing and chemical mechanical polishing are integrated. The ultrasonic elliptic vibration polishing technique was applied to polishing tool based on the traditional CMP technique. For utilization of the ultrasonic elliptic vibration from the polishing tool, the performance of polishing slurry is improved in the process of CMP, and the object is implemented to improve polishing result. By means of theoretical analysis combined with experimental research, the processing mechanism and technology of integrate polishing was studied systematically and thoroughly, and the main contents and innovations were included:1. The principle of the ultrasonic elliptic vibration polishing was introduced, and a theory model for designing the polishing tool was established. A polishing tool used in silicon wafer top surface and edge treatment was studied, then frequency-impedance and elliptical motion characteristics of polishing tools were tested.2. The experimental equipment of integrate polishing was developed based on traditional CMP, in order to realize different vibrations, such as ultrasonic longitudinal vibration, ultrasonic shear vibration and ultrasonic elliptic vibration.3. Base on CMP and USM, the mechanism of integrate polishing was analyzed systematically. According to the contact mechanics theory, the contact model between the wafer and the pad was built. On the basis of systematical studies for the influence of each main input parameters in machine polishing to quality characteristics of process surface, a simple and practical theoretical model for the material removing of integrate polishing was established. The fundamental researches of material remove mechanism and processing surface quality was developed based on three integrate polishing methods including ultrasonic longitudinal vibration, ultrasonic shear vibration and ultrasonic elliptic vibration. The results showed that the ultrasonic elliptic vibration of polishing tools was more advantageous to improve the effect of silicon chip synthesis polishing.4. In the situation of non-destructive work piece surface, a simple, practical and fast measurement method for micro-remove rate from the hard-brittle materials was studied.5. The experiments were studied on input process parameters, i.e., ultrasonic performance of polishing tool, polishing pressure, slurry supplying, wafer velocity at polishing point, polishing pad, which acted on the surface quality characteristics, surface roughness and material removal rate(MRR).6. The process rules of UEVCMHP were studied. The results showed that the integrate polishing technique could obtain better polishing surface qualities, more material removal and better no-smooth rate KR rate than the traditional chemistry machine polishing in the same conditions.In summary, hybrid polishing technique compared with tradition CMP has some improvement, whether in polishing surface quality or in MRR. There will be a important theory significance and project applicative values,which is rich in ultra-precise processing theory and enhances ultra-precise processing technique for the hard-brittle material.更多还原