Stochastic electron energy gain under sheath electric field near sidewall of chamber to drive inductively coupled magnetized plasmas

摘要

Single-electron motions near the sidewall of a chamber to drive a type of inductively coupled magnetized plasmas are analyzed using a Monte Carlo method in a simulation model with sheath electric field (E-sh) to understand the mechanism of electron energy gain (EEG). The analysis reveals that the E x B drift caused by E-sh, along the rf electric field induced in parallel to the sidewall, makes the EEG high and asymmetric between the first and second halves of an rf period. We observe spatial distributions of the EEG as a function of the distance from the wall under several sheath conditions. The EEG is higher under higher Esh and high EEG values are more concentrated in the sheath whose potential gradient is larger. Finally, observation of the phase-resolved EEG distributions demonstrates statistically that the EEG mechanism found in stochastic individual electron behaviors also works for a majority of electrons. (C) 2020 The Japan Society of Applied Physics.