基于逾渗与突变理论的硅片碎裂损伤跨尺度演化机理及抑制研究

Aiming at the problem that the edge fragmentation damage mechanism of hard and brittle materials, such as silicon wafers, is difficult to connect macroscopically and macroscopically, an acoustic emission method based on percolation and catastrophe theory is proposed to detect the mechanism of edge fragmentation damage in silicon wafer processing. Firstly, acoustic emission positioning, high-speed video observation, and damage morphology analysis are used to verify each other. And the damage law of edge fragmentation and the crack propagation characteristics are studied from the micro and macro levels. Secondly, combining acoustic emission technology with real-time monitoring signal characteristics of edge fragmentation damage evolution process, the critical catastrophe behavior, constitutive model and prediction model of silicon fragmentation damage are analyzed by using percolation and catastrophe theory, and the micro-macro multi-level evolution mechanism of edge fragmentation is revealed. Finally, the rule and mechanism of prestress control to restrain the fragmentation damage of silicon wafers are explored. It provides theoretical basis and technical support for comprehensively understanding the mechanism of edge fragmentation damage of hard and brittle materials and realizing damage prediction and control.

针对硅片等硬脆材料边缘碎裂损伤机理存在细-宏观跨尺度衔接难题，提出一种基于逾渗与突变理论的声发射探测硅片加工碎裂损伤机理研究方法。采用声发射定位、高速摄像观测、损伤形貌分析等多场探测方式相互验证，从细观、宏观两层次研究边缘碎裂的损伤规律与裂纹扩展特征；结合声发射技术实时监测边缘碎裂损伤演化过程信号的逾渗与突变特征，应用逾渗、尖点突变等理论方法分析晶体硅片边缘碎裂损伤的临界突变行为，构建边缘碎裂损伤的本构模型与预报模型，揭示晶体硅片边缘碎裂损伤的细观-宏观跨尺度多层次演化机理； 探究预应力控制方式抑制硅片碎裂损伤的规律与机理，优化相关的抑制措施。为全面认识硬脆材料的边缘碎裂损伤机理以及实现损伤预报与控制提供理论依据和技术支撑。

硅片作为重要半导体衬底材料被用于90%以上集成电路与光电器件，然而硅片微切削加工存在边缘碎裂损伤随机性大而难以控制的难题。针对硅片加工损伤机理及抑制措施还没有得到全面认识和开发，且边缘碎裂损伤研究体系中缺乏有效的实时监测技术与多层次跨尺度衔接理论，本项目开展了基于逾渗与突变理论的硅片碎裂损伤跨尺度演化机理及抑制研究。首先，采用损伤形貌分析、声发射时空定位、数值模拟仿真等多场探测方式相互验证，剖析了单晶硅片加工碎裂损伤规律及其裂纹扩展机制。其次，分析单晶硅片加工碎裂损伤演化过程的声发射信号特征，并聚焦硅片边缘碎裂损伤突变瞬间的临界行为特征，应用逾渗与突变理论方法构建边缘碎裂损伤预报模型，解决微宏观之间的损伤演变跨尺度衔接问题。最后，提出了一种胶黏固化增韧抑制硬脆材料加工边缘碎裂损伤的新方法，并开展了预应力增韧辅助抑制损伤技术研究，实现有效抑制单晶硅片边缘碎裂损伤。本项目研究成果为全面认识单晶硅的边缘碎裂损伤机理以及实现损伤预报、控制提供理论依据和技术支撑，为硅片的高效低损伤加工技术提供重要科学指导，利于推动集成电路与光电器件制造领域的发展。