A Study on a New Method to Measure Electron Energy Distribution in High Frequency Plasmas

提出了一种利用发射探针测量电子温度和电子能量分布函数的新方法。该方法是基于测量发射探头的浮电位与加热电压之间的函数关系。根据浮电位随加热电压变化的实测数据，与在麦克斯韦分布假设下得到的理论曲线进行比较，可以确定电子温度。浮电位变化的总体特征可以解释为加热电压的函数。在ar电感耦合等离子体的电子密度范围2.6×10^<11>-2.8×10^<12> cm^<-3>进行了实验验证。本研究以计算机辅助的方式开发了基于本方法的诊断工具原型。该方法还应用于13.56和60 MHz频率的表面波在陶瓷放电管中产生的SF_6刻蚀等离子体。本实验采用铼丝，测量了SF_6等离子体中的电子能和电子势。这些数据与在SF_6等离子体中得到的Si - 6速率一致。有人强调，本方法的优点在于探针在浮动状态下操作，因此适用于在绝缘容器中产生的等离子体。得到了电子能量分布函数。用表面波法在陶瓷放电管中制备SF_6刻蚀等离子体。

A new method to measure electron temperature and electron energy distribution function by an emissive probe has been proposed. The method is based on measurement of the functional relationship between the floating potential and the heating voltage of emissive probe. From the measured data of the floating potential change as a function of the heating voltage, the electron temperature could be determined by comparing with the theoretical curve obtained under the assumption of Maxwellian distribution. The overall characteristic of the floating potential change could be explained as a function of the heating voltage. The electron temperatures obtained by the present method were consistent with those measured by the rf-compensated Langmuir probe within the error, These experimental verifications were made in the electron density range of 2.6×10^<11>-2.8×10^<12> cm^<-3> in an inductively coupled plasma of Ar.In this study, a prototype of the diagnostic tool based on the present method was developed in a computer-aided fashion. The method was also applied to a SF_6 etching plasma which was produced in ceramic discharge tubes by surface-wave with the frequencies of 13.56 and 60 MHz. In this experiment, the Renium filament was employed, and the erectron energy as well as the potentials were measured in SF_6 plasma. These data were found to be consistent with the Si ecth rate obtained in the SF_6 plasma. It was stressed that the present method was advantageous in that the probe is operated in a floating condition, hence applicable to plasmas produced in an insulated container. The electron energy distribution function was also obtained in. SF_6 etching plasma which was produced in ceramic discharge tubes by surface-wave.