中国物理B ›› 2021, Vol. 30 ›› Issue (6): 65202-065202.doi: 10.1088/1674-1056/abe3f5

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Time-resolved radial uniformity of pulse-modulated inductively coupled O2/Ar plasmas

Wei Liu(刘巍)1,2,†, Chan Xue(薛婵)3, Fei Gao(高飞)4, Yong-Xin Liu(刘永新)4, You-Nian Wang(王友年)4, and Yong-Tao Zhao(赵永涛)2,‡   

  1. 1 School of Optoelectronic Engineering, Xi'an Technological University, Xi'an 710021, China;
    2 School of Science, Xi'an Jiaotong University, Xi'an 710049, China;
    3 School of Aerospace Science and Technology, Xidian University, Xi'an 710126, China;
    4 School of Physics, Dalian University of Technology, Dalian 116024, China
  • 收稿日期:2020-11-27 修回日期:2021-02-06 接受日期:2021-02-08 出版日期:2021-05-18 发布日期:2021-05-20
  • 通讯作者: Wei Liu, Yong-Tao Zhao E-mail:liuwei9238@outlook.com;zhaoyongtao@xjtu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11805150, 11875100, 11705141, and 11775282), the Dean Fund of the School of Optoelectronic Engineering (Grant No. 2019GDYT04), the Fund from the Xi'an Key Laboratory of Intelligent Detection and Perception (Grant No. 201805061ZD12CG45), and the Key Industry Innovation Chain Project of Shaanxi Provincial Science and the Technology Department, China (Grant No. 2018ZDCXL-GY-08-02-01).

Time-resolved radial uniformity of pulse-modulated inductively coupled O2/Ar plasmas

Wei Liu(刘巍)1,2,†, Chan Xue(薛婵)3, Fei Gao(高飞)4, Yong-Xin Liu(刘永新)4, You-Nian Wang(王友年)4, and Yong-Tao Zhao(赵永涛)2,‡   

  1. 1 School of Optoelectronic Engineering, Xi'an Technological University, Xi'an 710021, China;
    2 School of Science, Xi'an Jiaotong University, Xi'an 710049, China;
    3 School of Aerospace Science and Technology, Xidian University, Xi'an 710126, China;
    4 School of Physics, Dalian University of Technology, Dalian 116024, China
  • Received:2020-11-27 Revised:2021-02-06 Accepted:2021-02-08 Online:2021-05-18 Published:2021-05-20
  • Contact: Wei Liu, Yong-Tao Zhao E-mail:liuwei9238@outlook.com;zhaoyongtao@xjtu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11805150, 11875100, 11705141, and 11775282), the Dean Fund of the School of Optoelectronic Engineering (Grant No. 2019GDYT04), the Fund from the Xi'an Key Laboratory of Intelligent Detection and Perception (Grant No. 201805061ZD12CG45), and the Key Industry Innovation Chain Project of Shaanxi Provincial Science and the Technology Department, China (Grant No. 2018ZDCXL-GY-08-02-01).

摘要: Time-resolved radial uniformity of pulse-modulated inductively coupled O2/Ar plasma has been investigated by means of a Langmuir probe as well as an optical probe in this paper. The radial uniformity of plasma has been discussed through analyzing the nonuniformity factor β (calculated by the measured ne, lower β means higher plasma radial uniformity). The results show that during the active-glow period, the radial distribution of ne exhibits an almost flat profile at the beginning phase, but it converts into a parabola-like profile during the steady state. The consequent evolution for β is that when the power is turned on, it declines to a minimum at first, and then it increases to a maximum, after that, it decays until it keeps constant. This phenomenon can be explained by the fact that the ionization gradually becomes stronger at the plasma center and meanwhile the rebuilt electric field (plasma potential and ambipolar potential) will confine the electrons at the plasma center as well. Besides, the mean electron energy (<ε>on) at the pulse beginning decreases with the increasing duty cycle. This will postpone the plasma ignition after the power is turned on. This phenomenon has been verified by the emission intensity of Ar (λ=750.4 nm). During the after-glow period, it is interesting to find that the electrons have a large depletion rate at the plasma center. Consequently, ne forms a hollow distribution in the radial direction at the late stage of after-glow. Therefore, β exhibits a maximum at the same time. This can be attributed to the formation of negative oxygen ion (O-) at the plasma center when the power has been turned off.

关键词: plasma radial uniformity, pulse-modulated discharge, inductively coupled plasma, Langmuir probe

Abstract: Time-resolved radial uniformity of pulse-modulated inductively coupled O2/Ar plasma has been investigated by means of a Langmuir probe as well as an optical probe in this paper. The radial uniformity of plasma has been discussed through analyzing the nonuniformity factor β (calculated by the measured ne, lower β means higher plasma radial uniformity). The results show that during the active-glow period, the radial distribution of ne exhibits an almost flat profile at the beginning phase, but it converts into a parabola-like profile during the steady state. The consequent evolution for β is that when the power is turned on, it declines to a minimum at first, and then it increases to a maximum, after that, it decays until it keeps constant. This phenomenon can be explained by the fact that the ionization gradually becomes stronger at the plasma center and meanwhile the rebuilt electric field (plasma potential and ambipolar potential) will confine the electrons at the plasma center as well. Besides, the mean electron energy (<ε>on) at the pulse beginning decreases with the increasing duty cycle. This will postpone the plasma ignition after the power is turned on. This phenomenon has been verified by the emission intensity of Ar (λ=750.4 nm). During the after-glow period, it is interesting to find that the electrons have a large depletion rate at the plasma center. Consequently, ne forms a hollow distribution in the radial direction at the late stage of after-glow. Therefore, β exhibits a maximum at the same time. This can be attributed to the formation of negative oxygen ion (O-) at the plasma center when the power has been turned off.

Key words: plasma radial uniformity, pulse-modulated discharge, inductively coupled plasma, Langmuir probe

中图分类号:  (Plasma sources)

  • 52.50.Dg
52.25.-b (Plasma properties) 52.70.-m (Plasma diagnostic techniques and instrumentation)