【作者】 高碧荣；

【导师】 刘悦；

【作者基本信息】 大连理工大学 ， 等离子体物理， 2010， 硕士

【摘要】 随着低温等离子体技术的日益发展,具有无电极污染、放电气压低、产生等离子体密度高等突出优点的电子回旋共振等离子体也逐渐成为人们研究的重点之一。在电子回旋共振等离子体中,由于电离会直接影响到等离子体产生的性质,密度均匀性会直接影响到其应用于刻蚀、薄膜沉积等工艺时加工工件的质量。所以,对电离以及密度均匀性的研究是有意义的。另外,亚稳原子对等离子体中的电离、激发过程有着重要的贡献,考虑亚稳原子对电离及密度均匀性的影响也是具有一定意义的。本文以ECR等离子体源为研究对象,对ECR等离子体源磁场线圈电流产生的磁场运用麦克斯韦方程建立了数学模型,数值求解了所建立的模型得到了相应的磁场的数值结果。以该磁场为背景,基于磁流体理论,在漂移-扩散近似下,分别在考虑和没有考虑亚稳原子的情况下建立了ECR等离子体的物理模型。采用有限差分法对所建立的模型进行了自洽数值模拟,得到了微波电子回旋共振等离子体特性的数值结果。通过对两种模型下数值结果的分析比较,研究了ECR离子源操作参数(背景气体压强、微波功率和磁场线圈电流)及亚稳原子对电离和等离子体密度均匀性的影响。第一章主要介绍了微波电子回旋共振等离子体技术的原理、应用及研究现状。从理论到实践,使得我们对ECR等离子体有一个较全面的认识,并且可以看出,人们对ECR等离子体中电离、密度均匀性的研究相对较少,对ECR等离子体内亚稳原子的研究则更是几乎没有,这就使得我们的工作更加有意义；第二章对ECR等离子体源内电离、密度均匀性进行了研究,并主要针对ECR等离子体源操作参数对电离及密度均匀性的影响进行了详细的研究。另外,为了实现这一目的我们在本章前几节中详细给出了不考虑亚稳原子的ECR等离子体的数值模型,包括基本方程、边界条件、初始条件、数值方法等；第三章给出了考虑亚稳原子的电子回旋共振等离子体的数值模型,得到数值结果。并通过与第二章模拟所得数值结果进行比较,得出了亚稳原子对电离、密度均匀性的影响,使得我们对亚稳原子在ECR放电中的贡献有了更清楚的认识。最后对本文工作进行了总结和展望。更多还原

【Abstract】 With the development of low-temperature plasma technology, electron cyclotron resonance, which has advantages of no electrode contamination, low pressure operation, high plasma density, gradually becomes one of research topics. In ECR plasma, ionization can affect the characteristics of plasma; uniformity of plasma density can affect the quality of etching and thin film deposition. Thus, it is meaningful to study ionization and uniformity of plasma density. Besides, metastable atoms has important contribution to ionization and excitation. The study of the effect of metastable atoms on ionization and uniformity of plasma density is significant.The research object of this paper is microwave electron cyclotron resonance source. Using Maxwell equation, we established mathematical model of the magnetic field produced by the magnetic field coils. Then we got the numerical results of magnetic field by solving the model. On the background of the magnetic field, basing on theory of magnetic fluid, under drift-diffusion approximation, we established two 2-D fluid models, including no metastable atoms and considering metastable atoms, for the plasma in the chamber of electron cyclotron resonance plasma source. A finite difference method is used for self-consistent numerically simulating the models. Numerical results of the characteristics of ECR plasma are obtained. From the analysis and comparison of numerical results from two models, the effects of operational parameters of ECR plasma, including background gas pressure, microwave power and current in magnetic field coil, and metastable atoms on ionization and uniformity of the plasma density are researched.In the first chapter, the theory of ECR plasma technique, the applications of ECR plasma, the situation of study on ECR plasma are introduced. From the theory to the practice, our knowledge of ECR plasma is more comprehensive. Besides, we can see from this chapter that the research of ionization and density uniformity in ECR plasma is less, and the study of metastable atoms in ECR plasma is hardly any. Therefore, our work is meaningful.In the second chapter, ionization and density uniformity in ECR plasma, especially the effects of operational parameters of ECR plasma on ionization and density uniformity, are discussed as important aspects. The numerical model of ECR plasma, no metastable atoms, is established in detail, including basic equations, boundary conditions, initial conditions and numerical method.In the third chapter, the numerical model including metastable atoms is presented briefly. We got some numerical results. Comparing with the results from the second chapter, we mainly analyzed the effects of metastable atoms on ionization and uniformity of plasma density. We have a clearer knowledge of contribution of metastable atoms in ECR discharge by the research of this part.Finally, conclusions and the future work are given in the last chapter.更多还原