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

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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.