本文利用朗缪尔静电探针对掺入了电负性气体O2,C12,SF6的由4068MHz激发的单射频容性耦合Ar等离子体进行了诊断测量.测量结果表明:随着电负性气体流量的增加,电子能量概率分布函数出现了高能峰,高能峰且有向高能侧漂移的现象:电负性气体掺入AT等离子体后显著降低了等离子体的电子密度;电子温度随着电负性气体流量比的增加而升高.另外,本文还测量了掺入三种电负性气体后在不同流量比下的混合气体等离子体的电负度a.对实验现象进行了初步的解释.
Investigation of electronegative plasmas has now been atrractive due to the advantages of negative-ion assisted etching and charge- free ion implantation in semiconductor manufacture. Langmuir electrostatic probe, as a simple, inexpensive and good spatial resolution diagnosic tool, is popularly used in investigating electronegative plasmas. In this paper, the Langmuir electrostatic probe is proposed to measure the capacitively coupled Ar plasmas with added electronegative gases, such as 02, C12 and SF6. The experimental results from the measurements of At plasmas with added electronegative gases driven by a 40.68 MHz field indicate that, with increasing flow rate of electronegative gas, high energy peak will occur in electron energy possibility function and shift towards higher energyside. The addition of electronegative gases reduces the electron density significantly as the electron temperature increases. We also calculate the electronegativity of Ar plasmas for the three kinds of electronegative gases. The preliminary interpretations of the above experimental phenomena are presented.