Capacitively Coupled Plasma Breakdown: Simulation of Mechanisms, Circuitry, and Dynamics

This presentation synthesizes comprehensive investigations into radio-frequency (RF) capacitively coupled plasma (CCP) breakdown dynamics across diverse conditions, including Argon (Ar) and Carbon Tetrafluoride (CF₄) gases, pressures from mTorr to Torr, and varying RF frequencies and external circuitry. Utilizing primarily one-dimensional (1D) and two-dimensional (2D) implicit Particle-in-Cell/Monte Carlo Collision (PIC/MCC) simulations, with fluid models for specific medium-pressure regimes, elucidating intricate plasma initiation.

Breakdown processes are characterized through distinct pre-breakdown, breakdown, and post-breakdown phases, with focus on particle/power balance. Secondary Electron Emission (SEE), especially electron-induced SEE (ESEE), is critical at low pressures and high frequencies (e.g., 60 MHz), revealing glow, multipactor (normal/abnormal), and various failure modes (e.g., BFD, RFD).

External circuitry (e.g., L-type matching networks ) significantly impacts breakdown. Sheath formation dynamically alters plasma impedance and CCP equivalent capacitance, affecting circuit signals and harmonic generation. Matching optimization shows pressure-dependent effects. CF₄ discharges exhibit distinct pressure-dependent mode shifts.

2D simulations reveal spatial non-uniformities, electrode edge effects, and unique reversed breakdown patterns at very low pressures (e.g., 50 mTorr Ar). EEPF analysis shows non-Maxwellian distributions. Electrode self-bias evolution and detailed energy transport (absorption, flow, dissipation) are also investigated. These insights are crucial for optimizing industrial plasma processes (etching, PECVD), enhancing uniformity, and advancing gas discharge physics.