High-frequency voltage effects on power deposition and ion dynamics in tailored waveform driven capacitively coupled plasmas

Dual-frequency capacitively coupled plasmas are widely utilized in semiconductor processing, where precise control of ion energy and flux is critical. Tailored voltage waveforms (TVWs) generated by advanced power supplies enable improved control over ion energy distribution functions (IEDFs). In this study, the conventional low-frequency sinusoidal waveform is replaced with a 400 kHz triangular-shaped TVWs to investigate effects on sheath dynamics, field structures, and particle energy transport. Fully kinetic particle-in-cell/Monte Carlo collision simulations in argon at 0.66 Pa (5 mTorr) are performed between electrodes separated by a 5 cm gap, with a sinusoidal high frequency (HF) of 60 MHz and HF voltages varied between 200 and 600 V. The TVW induces asymmetry in both sheath structure and time-averaged plasma potential, altering ion acceleration and plasma dynamics. Electric field reversals are influenced by TVW and HF amplitude, with the reversed field magnitude reaching up to 40 kV/m and increasing in frequency and intensity with HF voltage. The TVWs eliminate the bimodal ion energy distribution characteristic of conventional sinusoidal waveforms and enable high-energy ion flux to one electrode while the other receives low-energy ions, benefiting electrode longevity. We discuss how varying the HF amplitude influence the peak structure in the IEDFs and result in energetic, highly directional electron flux that may help mitigate surface charging in high-aspect-ratio features. The rapid transient currents arising from TVW-driven sheath dynamics and HF modulation impose stringent demands on RF power supply design, requiring fast current delivery and stable voltage regulation.