电感耦合等离子体放电特性的三维仿真研究

Three-Dimensional Simulation Research on Discharge Characteristics of Inductively Coupled Plasma

针对电感耦合等离子体(ICP)的放电问题,设计了一种闭式透波腔体构型,建立了ICP的流体力学模型,并利用多物理场仿真平台COMSOL进行三维仿真研究。分析了放电过程中电子密度、电子温度和等离子体电势等典型参数随时间的变化规律,在此基础上改变射频电源的功率、腔体内气压等条件,获得ICP的参数范围以及空间梯度分布。结果表明,放电功率主要影响等离子体参数的数值范围,而气压的改变则对等离子体参数的数值和空间分布都会产生影响。当射频电源功率从100 W增加到300 W时,电子密度峰值从2.54×10^(17) m^(-3)增加到5.68×10^(17) m^(-3),同时反应稳定后加热区感应出的电势和相应的电子温度呈现小幅降低;腔内气压在一定范围内升高会使得电子密度明显增加,气压从10 Pa增加到30 Pa,电子密度从9.12×10^(17) m^(-3)上升到3.62×10^(18) m^(-3),但气压过高会导致等离子体参数分布的均匀性变差。

Aiming at the discharge problem of inductively coupled plasma(ICP),a closed wave-transmitting cavi-ty configuration is designed,the fluid mechanics model of ICP is established,and the multi physical simulation software COMSOL is used for three-dimensional simulation research.The variation laws of typical parameters such as electron density,electron temperature and plasma potential with time in the discharge process are analyzed.On this basis,the power of radio frequency power supply,the air pressure in the cavity and other conditions are changed to obtain the parameter range and spatial gradient distribution of ICP.The results show that the discharge power mainly affects the numerical range of plasma parameters,and the change of air pressure has an effect on the numerical value and spatial distribution of plasma parameters.When the power of radio frequency power supply increases from 100 W to 300 W,the peak electron density increases from 2.54×10^(17) m^(-3) to 5.68×10^(17) m^(-3),and the electric potential induced in the heating zone and the corresponding electron temperature decrease slightly after the reaction is stable.Increasing the air pressure in the cavity within a certain range will significantly increase the electron density.The air pressure increases from 10 Pa to 30 Pa,and the electron density increases from 9.12×10^(17) m^(-3) to 3.62×10^(18) m^(-3).However,the uniformity of plasma parameter distribution will deteriorate if the air pressure is too high.