A numerical study of capacitively coupled plasma driven by tailored voltage waveforms under electron beam injection and magnetic field modulation

In this study, a one-dimensional particle-in-cell/Monte Carlo collision model is developed to investigate the effects of harmonic number and magnetic field variation on electron beam modulation discharges. The results show that increasing the harmonic number leads to greater voltage waveform asymmetry, which enhances sheath expansion on the powered electrode side. This enables more effective electron acceleration, resulting in higher plasma density, elevated electron temperature near the powered sheath, and the formation of a self-bias voltage. Additionally, under a fixed harmonic number, increasing the magnetic field strength initially increases the plasma density due to extended electron paths that enhance ionization. However, at stronger fields, the electron Larmor radius decreases, leading to more localized ionization near the injection side and reduced overall density. The ion energy distribution function at the powered electrode becomes narrower with decreasing peak energy, while that at the grounded electrode shows an increasing and broadened energy spectrum. These findings provide guidance for optimizing plasma density and ion energy control in plasma processing applications.