不同激发频率下小型感应耦合等离子体特性研究

Driving Frequencies and Characteristics of Miniaturized Inductively Coupled Plasma Sources

等离子体小型化后往往会产生一些独特的等离子体性质。本文采用朗谬尔探针和高分辨率发射光谱技术对不同激发频率下产生的小型感应耦合等离子体进行了测量,选用的三种频率为13.56MHz,27.12MHz和40.68MHz。朗谬尔探针的实验结果表明,随着射频输入功率的增加以及激发频率的上升均会导致等离子体功率吸收的增强,从而导致了离子密度增大和电子温度下降。利用了气体追踪法测量感应放电中的气体温度,可以发现,由于电子诱导加热的作用,气体温度随气压和输入功率的增加而增加,射频频率的提高也有助于等离子体气体温度的上升。

A novel type of the miniaturized inductively coupled plasma source was developed. The impacts of the operating conditions, such as the input power, driven frequency, and gas temperature, on characteristics, including the plasma density,electron temperature and current-voltage curve, were studied with Langmuir probe and optical emission spectroscopy （OES）.The results show that the driving frequency significantly affects the properties of the plasma. For instance, as the input power and/or the driving frequency increases, the power absorption of the plasma increases, accompanying with an increasing plasma density and a decreasing electron temperature. Besides, the gas temperature rises up with an increase of gas pressure or input power or driving frequency, possibly because of the electron induced heating.