Influence of collision processes in the sheath on ion energy distribution functions in radio frequency discharges

This paper investigates the influence of collision processes within the sheath on ion energy distribution functions (IEDFs) in a low-pressure dual-frequency capacitively coupled plasma (DF-CCP). Through the use of a 1D3V particle-in-cell/Monte Carlo collision model, the roles of ionization and charge-exchange collisions in the formation of an additional low-energy peak in the IEDF are explored. The simulations indicate that the additional energy peak primarily arises from ionization collisions that occur within a single cycle, while charge-exchange collisions contribute increasingly over multiple cycles. These findings highlight the complex dynamics of ion energy distributions in DF-CCPs, providing valuable insights for optimizing plasma processing in microelectronics.