相位分辨光学发射光谱学:一种用于研究电容射频放电中电子动力学的非介入式诊断方法
Various types of capacitively coupled radio frequency (CCRF) discharges are frequently usedfor different applications ranging from chip and solar cell manufacturing to the creation ofbiocompatible surfaces. In many of these discharges electron heating and electron dynamicsare not fully understood. A powerful diagnostic to study electron dynamics in CCRFdischarges is phase resolved optical emission spectroscopy (PROES). It is non-intrusive andprovides access to the dynamics of highly energetic electrons, which sustain the discharge viaionization, with high spatial and temporal resolution within the RF period. Based on a timedependent model of the excitation dynamics of specifically chosen rare gas levels PROESprovides access to plasma parameters such as the electron temperature, electron density andelectron energy distribution function (EEDF). In this work the method of PROES is reviewedand some examples of its application are discussed. First, the generation of highly energeticelectron beams by the expanding sheath in geometrically symmetric as well as asymmetricdischarges and their effect on the EEDF are investigated. Second, the physical nature of thefrequency coupling in dual frequency discharges operated at substantially different frequenciesis discussed. Third, the generation of electric field reversals during sheath collapse in singleand dual frequency discharges is analysed. Then excitation dynamics in an electricallyasymmetric novel type of dual frequency discharge is studied. Finally, limitations of PROESare discussed.