空心电极对容性耦合等离子体放电特性影响  

Effect of hollow electrode on plasma characteristics in capacitively coupled discharge

作　　者：李鹏博 梁英爽 LI Pengbo;LIANG Yingshuang(School of Science,University of Science and Technology Liaoning,Anshan 114051,China)

机构地区：[1]辽宁科技大学理学院,辽宁鞍山114051

出　　处：《辽宁科技大学学报》2023年第5期393-400,共8页Journal of University of Science and Technology Liaoning

基　　金：国家自然科学基金资助项目(11805089);辽宁省教育厅项目(LJKMZ20220657)。

摘　　要：为了提高容性耦合等离子体源的等离子体密度,采用空心电极来代替传统平板电极进行放电。本文采用流体力学模型对容性耦合空心电极放电进行建模仿真,研究不同空心电极的孔隙结构、放电电压及极板间距下,空心电极对容性耦合等离子体放电特性,特别是对等离子体密度的影响。结果表明,采用传统平板电极放电得到的等离子体密度仅为1.86×10^(15)m^(-3);当采用倒梯形孔隙结构空心电极进行放电时,空心阴极效应被抑制,等离子体密度仅有少量增长;采用矩形或梯形孔隙结构的空心电极进行放电时,孔隙下方的等离子体密度显著提高,达到2.37×10^(15)m^(-3)以上。研究还发现,随着放电电压从50 V增至125 V,空心阴极效应和静电边缘效应都显著增强,放电中心处的电子密度从4.76×10^(14)m^(-3)迅速增加到3.98×10^(15)m^(-3),但等离子体密度在径向分布上出现两个明显的峰值,导致均匀性变差。随着极板间距的增加,等离子体密度显著提高,等离子体均匀性受扩散效应的影响得到明显改善。A hollow electrode has been proposed to replace the classical flat electrode to improve the plasma density of capacitively coupled plasma sources.In this paper,a fluid model was built to study the effects of groove shapes of hollow electrodes,discharge voltages,and electrode gaps on the plasma characteristics,especially the plasma density,in the CCP discharges.The results show that the plasma density is only 1.86×10^(15)m^(-3)in the conventional CCP discharge.When the shape of the groove is an inverted trapezoid,the increase in the plasma density is not significant because the hollow cathode effect is suppressed.By contrast,the plasma density below the groove area becomes much higher when the groove is rectangular or trapezoid,with a value of higher than 2.37×10^(15)m^(-3).It is also found that,as the discharge voltage increases from 50 V to 125 V,the plasma density at the reactor center reaches to 3.98×10^(15)m^(-3)from 4.76×10^(14)m^(-3)due to the enhanced hollow cathode effect and electrostatic edge effect,which also leads to two peaks in the plasma density radial distribution,indicating a worse plasma uniformity.Finally,with the growth of electrode gap,the plasma density increases significantly,and the plasma uniformity is improved attributed to the stronger diffusion effect.

关 键 词：空心电极放电 容性耦合等离子体 等离子体密度 数值模拟 

分 类 号：O531[理学—等离子体物理]