Modulating Capacitively Coupled Plasma Characteristics using F^- Ion Beam Injection

The characteristics of capacitively coupled plasma (CCP) not only can be modulated not only through the traditional method of using a radio frequency (RF) source but also by employing electron beam and positive ion beam injection^[1-5]. In this study, a negative ion beam (IB) source is employed to inject into the discharge region of pure CF₄ plasma. The implicit PIC/MCC method is used to simulate the stable discharge after IB injection. The results demonstrate that IB injection effectively enhances plasma density and ion. Additionally, the heating mode of the plasma shifts from the drift-ambipolar (DA) mode to a hybrid α-γ-DA mode with IB injection. Furthermore, an increase in IB current leads to a corresponding increase in plasma density. After the injection of ion beams, a significant variation in the self-bias voltage on the power electrode is observed under different gas pressure conditions. This research contributes to the understanding of CCP modulation and its potential application in thin film deposition and material surface cleaning processes.