Numerical Characterization of Argon Plasma under Repetitive Pulsed Extreme Ultraviolet Irradiation

Under repetitive pulsed extreme ultraviolet (EUV) irradiation conditions, plasma significantly affects the lifetime and stability of optical components in EUV lithography tools. To investigate this phenomenon, we developed and validated a two-dimensional implicit electrostatic Particle-in-Cell/Monte Carlo Collisions (PIC/MCC) numerical model to predict key parameters such as electron density, potential, electron energy probability functions (EEPF), and ion flux. Simulations show that at low pressure (1 Pa), argon plasma exhibits negligible accumulation effects and rapidly dissipates energy after each pulse. Notably, an inverse sheath does not form under these low-pressure conditions. Conversely, at higher pressure (5 Pa), increased collision rates induce significant accumulation effects, enhancing plasma density and altering potential distributions, including the formation of an inverse sheath. These findings provide valuable insights for optimizing EUV lithography processes and enhancing the understanding of EUV-induced plasma interactions.