Experimental investigation of the electromagnetic effect and improvement of the plasma radial uniformity in a large-area,very-high frequency capacitive argon discharge

作     者：Daoman HAN Zixuan SU Kai ZHAO Yongxin LIU Fei GAO Younian WANG 韩道满;苏子轩;赵凯;刘永新;高飞;王友年

作者机构：Lab of Advanced Space Propulsion and Beijing Engineering Research Center of Efficient and Green Aerospace Propulsion TechnologyBeijing Institute of Control EngineeringBeijing 100190People’s Republic of China Key Laboratory of Materials Modification by LaserIonand Electron Beams(Ministry of Education)School of PhysicsDalian University of TechnologyDalian 116024People’s Republic of China 

出 版 物：《Plasma Science and Technology》 (等离子体科学和技术（英文版）)

年 卷 期：2021年第23卷第5期

页      面：66-74页

核心收录：

学科分类：07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 070204[理学-等离子体物理] 0702[理学-物理学] 

基　　金：funded by National Natural Science Foundation of China (Nos. 11875100, 11935005 and 11722541) financial support from the China Scholarship Council 

主　　题：electromagnetic effect plasma radial uniformity very-high-frequency capacitively coupled plasmas 

摘      要：We performed an experimental investigation on the electromagnetic effect and the plasma radial uniformity in a larger-area, cylindrical capacitively coupled plasma reactor. By utilizing a floating hairpin probe, dependences of the plasma radial density on the driving frequency and the radio-frequency power over a wide pressure range of 5-40 Pa were presented. At a relatively low frequency(LF, e.g. 27 MHz), an evident peak generally appears near the electrode edge for all pressures investigated here due to the edge field effect, while at a very high frequency(VHF, e.g.60 or 100 MHz), the plasma density shows a sharp peak at the discharge center at lower pressures, indicating a strong standing wave effect. As the RF power increases, the center-peak structure of plasma density becomes more evident. With increasing the pressure, the standing wave effect is gradually overwhelmed by the ‘stop band’ effect, resulting in a transition in the plasma density profile from a central peak to an edge peak. To improve the plasma radial uniformity, a LF source is introduced into the VHF plasma by balancing the standing wave effect with the edge effect. A much better plasma uniformity can be obtained if one chooses appropriate LF powers, pressures and other corresponding discharge parameters.