阻挡材料对射频容性耦合等离子体放电参量的影响

The Effect of Barrier Material on Discharge Parameters of RF-CCP

为进一步探索射频容性耦合等离子体放电影响因素,本文运用数值仿真技术,构建了容性耦合等离子体的一维发射装置,施加射频源,仿真气体设定为氦气,极板间距恒定75 mm,研究了插入阻挡材料厚度、介电常数对极板间周期平均电子密度、周期平均电子温度及周期平均电势的影响。仿真结果显示:插入阻挡材料的介电常数越大,气体间隙中间的周期平均电子密度最大值越大,高电子密度区域的周期平均电势最大值越小,阻挡材料附近的周期平均电子温度极大值越加,但气体中间极小值基本不变;周期平均电子密度最大值随阻挡材料厚度的增加先增后减,阻挡材料厚度具有最优值,且随着介电常数增大,最优值增加;周期平均电势最大值及阻挡材料与气体边界处的周期平均电势值虽都与阻挡材料厚度呈正比,但两者差值随阻挡材料厚度增加近似不变。所得结论对改进传统的射频容性耦合等离子体获取具有重要意义。

In order to further explore the influencing factors of radio frequency capacitively coupled plasma(RF-CCP),a one-dimensional emission device of CCP was constructed using the numerical simulation method.The RF source was applied,and the simulation gas was set to helium,with a constant distance of 75 mm between the plates.This paper studies the effects of the thickness and dielectric constant of the inserted barrier material on the average electron density,average electron temperature,and potential between electrode plates.The simulation results are as follows:The larger the dielectric constant of the inserted barrier material,the larger the maximum value of the periodic average of electron density in the middle of the gas gap,the smaller the maximum value of the periodic average of potential in the high electron density region,and the larger the maximum value of the periodic average of electron temperature near the barrier material,but its minimum value in the gas gap middle is basically the same.With the increase of the thickness of the barrier material,the maximum value of the periodic average of electron density first increases and then decreases.The thickness of the barrier material has an optimal value,and the optimal value increases with the dielectric constant.Although the maximum values of the periodic average of potential and the periodic average of potential at the boundary between the barrier material and the gas are proportional to the thickness of the barrier material,their differences are approximately constant as the thickness of the barrier material increases.These results have a great significance for improving the performance of traditional RF-CCP.