电源接入方式对双频容性耦合等离子体性质的影响

Effects of power supply access mode on the properties of dual-frequency capacitively coupled plasma

采用发射光谱结合碰撞辐射模型的方法,研究27.12和2.00 MHz双频电源放电时单极双频(两个射频电源接在一个电极上)和双极双频(两个射频电源接在两个电极上)对双频容性耦合氩等离子体的电子温度和电子密度轴向分布的影响。结果发现:双极双频时的电子密度比单极双频时的高,且其中间等离子体主体区域的电子密度更加平稳和对称,而单极双频时靠接地电极一侧电子密度有一些下降,这与在接地电极附近电子损失相对较多以及高、低频电源在混频器上干扰等因素有关;双极双频时电子温度分布也更加对称和平稳。因此,双极双频接法对电子约束更好,使得高频电源和低频电源馈入等离子体的效率更高。

By combination emission spectra with collision radiation model,the effects of unipolar dual-frequency(two radio frequency power supplies connected to one electrode)and bipolar dual-frequency(two radio frequency power supplies connected to two electrodes)on the axial distribution of electron temperature and density of the dual-frequency capacitive coupling argon plasma are studied when the dual-frequency(27.12 and 2.00 MHz)power supplies discharge.The results show that the electron density of the bipolar dual-frequency is higher than that of the unipolar dual-frequency,and the electron density of the main area of the plasma in the middle is more stable and symmetrical,while the electron density of one side of the unipolar dual-frequency near the ground electrode decreases a little,which is related to the factors such as relatively more electron loss near the ground electrode,and the interference of high and low frequency power supply on the mixer.The temperature distribution of the electron is more symmetrical and stable when the bipolar dual-frequency is used,so the bipolar connection method has better electronic constraints,which makes higher efficiency of the high-frequency power supply and low-frequency power supply feeding into the plasma.