Analysis of dynamics of particles suspended in non-equilibrium rf plasma space

本研究的目的是通过测量粒子的性质和运动来了解非平衡等离子体场中产生的细粒子的生长过程和输运现象。研究期间的研究成果总结如下：1。通过在等离子体反应器中安装在线粒子测量系统，对等离子体中细粒子的空间分布进行了详细的测量。用试验颗粒确定了可测颗粒的大小和浓度范围。用等离子体气相沉积法制备SiO_2和Si薄膜时所产生的微粒的性质可以被测量。悬浮微粒在等离子体和等离子体后场中的输运、沉积行为和捕获现象可以通过粒子的可视化来评价。通过对等离子体测量装置的测量和数值模拟，得到了表征等离子体场的几个参数的空间分布。考虑上述参数，导出了描述颗粒带电和混凝过程的理论模型。用模型预测的粒子行为与实测结果吻合较好。基于等离子体中带电细粒子所受的各种力，推导了粒子输运模型，并制作了一个数值模拟器。用实测结果对模型和仿真器进行了验证。提出了一种控制等离子体中细粒子输运的技术，并通过实际装置验证了该技术的有效性。结合粒子输运模型分析了等离子体中细颗粒的凝固生长模型，明确了等离子体中细颗粒大小的调控机制。

The purpose of this study has been to understand the growth processes and transport phenomena of fine particles generated in a non-equilibrium plasma field by measuring the properties and motion of the particles. The research results in the research period are summarized as follows.1.Detailed measurements of the spatial distribution of fine particles in plasma was made possible by installing an in-line particle measurement system in a plasma reactor equipped with an in situ laser light scattering measurement system. The range of the measurable size and concentration of particles was determined by using test particles. The properties of fine particles could be measured for those generated in the plasma CVD processes for thin film fabrication of SiO_2 and Si. The transport and deposition behavior and trapping phenomena of fine particles suspended in plasma and post-plasma fields could be evaluated by visualization of the particles.2.The spatial distribution of several parameters characterizing a plasma field was obtained by measurements using plasma measurement devices and numerical simulation. Theoretical models for describing the processes of particle charging and coagulation were derived by considering the above parameters. Particle behavior predicted with the models was found to agree satisfactorily with measured results.3.A numerical simulator was prepared by deriving a particle transport model based on the various forces acting on charged fine particles in plasma. The model and the simulator were validated with measured results. A technique for controlling the transport of fine particles in plasma was also proposed and its efficiency was verified by building an actual device based on the technique.4.The model for coagulational growth of fine particles in plasma was analyzed in conjunction with the particle transport model, which made clear the mechanisms governing the size of fine particles generated in plasma.