基于蒙特卡罗的各向异性湿法腐蚀模拟研究毕业论文定稿.docVIP

基于蒙特卡罗的各向异性湿法腐蚀模拟研究 硕士研究生： 导师： 东南大学机械工程学院 摘要 论文研究了Metropolis Monte Carlo方法在硅微加工各向异性湿法腐蚀仿真中的应用。针对硅微湿法加工所涉及的关键技术和实现方法进行了分析。并在此基础上开发了三维腐蚀加工仿真系统。主要的研究内容如下： 首先，基于Monte Carlo方法，在台阶流动（step flow）模型上引入了腐蚀概率方程，以一级邻居原子和二级邻居原子数量判断原子类型，确定蒙特卡罗转移概率。编制程序的模拟结果在不同晶向以及掩模作用下，能与实验结果一致，解释了蒙特卡罗法处理复杂晶面的原理和应用过程。 对比分析了其它基于原子模型的仿真方法，以凸角补偿工程实例测试了模型的效率和结果精度，阐述了Metropolis Monte Carlo方法的优势和应用特点。更进一步，系统实现了模拟研究腐蚀中出现的（100）面金字塔凸起、（110）面锯齿状条纹以及（111）面三角形凹陷等微观表面形态，并支持微加工中表面粗糙度的计算。 开发的系统具备描述氧化硅以及氮化硅掩模作用下的各项异性腐蚀过程的能力，实现了连续多次掩模多步硅微加工工艺过程的仿真。通过模拟一个原子力显微镜探针阵列的多次掩模连续6步工艺的硅微加工过程验证了系统的模拟能力。 最后，探讨了微系统的设计与分析集成技术。在原子模型转换到有限元结构分析过程中，直接使用模拟出的晶面结构利用网格划分理论得到了腐蚀结果的有限元模型。开发的系统由inp文件导入有限元软件ABAQUS中。分析计算表明该方法具有可行性，能够达到微器件结构的设计仿真与FEM分析的集成要求。 关键词：Metropolis蒙特卡罗；单晶硅；各向异性；湿法腐蚀；模拟 The study of Monte Carlo simulation approach for anisotropic wet etching Candidate for Master: Adviser: Southeast University ABSTRACT The simulation model based on Metropolis Monte Carlo for anisotropic etching has been studied after analyzing the fundamental mechanism and fabrication process of etching. The simulator has been developed to calculate the emerging shape in 3D geometries. The focuses of this work are as the following. First, the step flow model of kink propagation is introduced in modeling process of etching by using Monte Carlo method. For the calculation of transaction probability of Monte Carlo algorithm, the removal probability function is set forth through the nearest-neighbors-counting model. The characteristics on different facets and the structure of the convex corner under the compensated mask calculated by the program agree well with the experimental result, which provides a good explanation of the complex facets appeared during etching. Comparing with the other atomistic methods in etching, this model shows the features of higher efficiency and better accuracy. For microscopic surface structure, it can produce the pyramid hillock on (100) facet, zigzag structure on (110) facet, triangular hollow on (111) facet in simulation. F