Research On Low-power Microwave Plasma

As the low-power microwave plasma source based on micro-system has attracted more and more attention in recent years, researchers are dedicated to obtain a miniaturized plasma source with long lifetime, steady state, low power, high efficiency and no electrode pollution. Low-power microwave plasma source is usually classified into two kinds, one is capacitively-coupled plasma source; the other is inductively-coupled plasma source (ICPS). ICPS has got a widespread use due to its advantage in parameters controlled, pollution-free, steady work-state.The planar spiral inductively-coupled antenna is analyzed in this thesis, and a new gradient structure based on traditional ICPS is proposed. In the new structure, the space between adjacent conductors is narrow in the center, and it becomes wider and wider as the radius increases. Equivalent electromagnetic source method is used to analyze the electromagnetic fields excited by the ICPS.Based on the new structure, a gradient ICPS working at 2.45GHz is designed. Simulating software CST and HFSS are employed to calculate its parameters. Under same condition higher Q value and stronger field can be obtained by the gradient ICPS, which raises efficiency in converting the source power to field power. The impact of enforced DC magnetic field to the plasmas and plasmas source is also investigated by using equivalent permittivity method。Finally some experiments are carried out to verify the performance of the new structure ICPS.