Two-dimensional simulation of capacitively coupled plasma breakdown under low-pressure conditions

Abstract This study presents a comprehensive two-dimensional implicit electrostatic particle-in-cell with Monte Carlo collisions simulation of capacitively coupled plasma breakdown dynamics under varying pressure conditions. We investigate the spatiotemporal evolution of plasma parameters during breakdown in argon at 50 mTorr and 100 mTorr. Our results reveal a significant pressure dependence in breakdown behavior and spatial uniformity. At 50 mTorr, extended electron mean free paths lead to elevated electron energy and densities in regions distant from the electrodes, resulting in a reversed breakdown pattern where plasma initiates away from the electrodes. Conversely, at 100 mTorr, breakdown initiates near the electrodes, producing a more uniform plasma distribution. Analysis of the electron energy probability function demonstrates that lower pressures facilitate Maxwellian electron distributions with increased high-energy populations, influencing ionization rates and plasma stability. The formation of a negative electrode bias voltage is closely linked to sheath dynamics and differential charge transport, highlighting the self-regulating nature of plasma-sheath interactions in CCP systems.