Effect of driving frequency on electrostatic and electromagnetic fields in capacitively coupled Ar plasmas using a two-dimensional particle-in-cell simulation

Capacitively coupled plasma (CCP) is widely used in semiconductor etching and deposition processes due to its high spatial uniformity. To enhance process yield, there is a growing trend toward using high-frequency (HF). However, in large-area plasma systems, HF operation generates complex phenomena, such as standing wave effects, which are not observed in small-area or low-frequency (LF) discharges. Accurate simulation under these conditions requires resolving the electron energy distribution function, including nonlinear and transient kinetic effects. Geometrical effects also play an important role in plasma behavior, yet most simulations have been limited to 1D or micro-scale 2D models due to computational load when considering dual-frequency (DF) or electromagnetic (EM) effects. To overcome this, we developed a high-performance, GPU-parallelized, two-dimensional (2D) Particle-in-Cell (PIC) simulation. In this study, we analyzed electropositive plasma uniformity by comparing electrostatic (ES) and EM effects with various RF frequencies. Even in ES-only cases, a center-heavy plasma density builds with increasing frequency. When adding the EM effects, the relative contribution of the EM component grows with frequency, and a phase difference in the EM field occurs. Therefore, the EM effect further enhances the localized plasma density growth at the center. As future work, we will investigate DF effect with non-sinusoidal bias waveform, better reflecting realistic etching conditions.