【作者】 张银霞；

【导师】 康仁科；

【作者基本信息】 大连理工大学 ， 机械制造及其自动化， 2006， 博士

【摘要】 单晶硅片是集成电路(IC)制造过程中最常用的衬底材料，硅片的表面层质量直接影响着器件的性能、成品率以及寿命。随着硅片尺寸的增大，新的硅片高效超精密平整化加工工艺得到了大量的研究，其中，具有高效率、高精度、低损伤等优点的硅片自旋转磨削技术正逐步成为抛光硅片和图形硅片背面减薄的主流加工技术。然而，磨削加工会不可避免地给硅片带来表面层损伤，该损伤会影响后续抛光工序的抛光时间和硅片的加工效率。目前，对硅片磨削表面层损伤机理的研究还不完善，深入研究硅片磨削表面层损伤机理对最终实现硅片的高效率、高精度、无损伤、超光滑表面的加工有着重要的指导意义。 本文在深入分析硅片加工表面层损伤的研究现状及存在问题的基础上，对硅片自旋转磨削加工表面层损伤进行了研究。论文的主要研究工作有： (1) 结合硅片加工表面层损伤形式，分析硅片加工表面层损伤的检测技术，通过大量试验确定硅片磨削加工表面层损伤检测技术与试验方案。 (2) 通过系统的TEM和显微Raman光谱检测分析，研究了粗磨、半精磨、精磨硅片的表面层损伤形式、形成原因及变化规律；研究了单颗磨粒磨削硅片和金刚石砂轮磨削硅片表面层微裂纹的特征与分布；分析了磨削时单晶硅的相变过程。 (3) 对单颗磨粒磨削硅片和金刚石砂轮磨削硅片表面层残余应力的分布进行了研究，分析了残余应力的产生原因。 (4) 对自旋转磨削硅片上不同位置处的损伤深度进行检测分析，研究了硅片表面的损伤分布；研究了磨削参数对损伤深度的影响。 通过系统的试验研究和理论分析，本文所取得的主要结论如下： (1) 粗磨硅片的表面层损伤由大量的形状复杂的微裂纹、高密度位错、层错及弹性畸变层组成，其中以微裂纹、位错及层错为主，损伤深度为8～17μm；半精磨和精磨硅片的损伤层中除了以上的损伤形式外，还观察到有非晶层和多晶层存在，且微裂纹明显减少，损伤深度分别为2.5～5μm和0.7～1.4μm；从半精磨到精磨，硅片的非晶层厚度由约110nm减小至约30nm，且非晶层厚度分布逐渐变得均匀。在以上基础上建立了硅片磨削表面层损伤模型。 (2) 半精磨和精磨硅片表面层存在的a-Si相、Si-Ⅲ相、Si-Ⅳ相和Si-Ⅻ相表明磨削过程中Si-Ⅰ相发生了金属相变(Si-Ⅱ相)，Si-Ⅱ相容易以塑性方式去除；但材料的塑性去除程度大小和相变强度大小没有比例关系，粗磨向半精磨过渡时，随着相变强度更多还原

【Abstract】 Monocrystalline silicon wafers are the most widely used substrates in IC manufacturing fields. The surface layer quality directly affects the property, the rate of finished products and the lifetime of IC device. With the increasing of the wafer diameter, some new processes for wafer machining are being researched. Wafer rotation grinding, as a precision grinding method, is widely used in manufacturing and back thinning process of silicon wafer due to its low damage, high precision and efficiency. However, grinding would inevitably bring about surface layer damage and the damage will severely affect the process time of the subsequent polishing procedure. Although many researchers study the machined wafer damage, the damage mechanism of the wafer rotational grinding is not yet perfectly understood. Therefore, the research regarding the surface layer damage in wafer rotation grinding has an important significance for realizing process of the wafer with high efficiency, precision, undamaged and ultra-smooth surface.Based on adequate analysis of research background, the rotation ground wafer surface layer damage is studied in this paper. The main research work is listed as follows:(1) Base on different damage forms, the wafer surface layer damage measurement methods are analyzed. Damage measurement methods and the implementation schemes are determined by doing abundant experiments.(2) The change rules and the generation reasons of wafer damage microstructure induced in rough, semi-fine and fine grinding are studied by using TEM and Raman microspectroscopy. The surface layer microcrack configuarations and distribution of single diamond grit ground and diamond wheel ground wafer are also studied. The phase transformation of the monocrystalline silicon during grinding is analyzed as well.(3) The residual stress distributions of single diamond grit ground and diamond wheel ground wafer surface layer are studied. The generation reasons of residual stress are analyzed.(4) The subsurface damage depths (SSD) of different positions on the rotation ground wafer surface are detected and analyzed. The damage distribution rules and the effects of the grinding parameters on the SSD are studied.The following conclusions are obtained by systematical experimental study and theoretical analysis:(1) Rough ground wafer surface layer damage is composed of large quantity of microcracks with complicated configuarations, high density dislocations, stalk faults and elastic deformation layer. Among them microcracks, dislocations and stalk faults are dominant. The SSD is 8~ 17 μm. Apart from the above damage forms, amorphous layer and polycrystalline layer exist in the semi-fine and fine ground wafer surface layer damage, and更多还原