New insights into electron heating in capacitive RF plasmas | Dr. Julian Schulze (Ruhr University Bochum

Resumen:

Understanding and controlling the electron heating dynamics in low temperature capacitive radio frequency discharges is the basis for plasma process optimization based on scientific understanding. Here, a novel approach towards analyzing this complex non-linear and non-local phenomenon at low pressures in electropositive gases based on moments of the Boltzmann equation and PIC/MCC simulations is presented. In contrast to previous works on this topic a complete space and time resolved understanding is obtained. It is found that a temporal asymmetry of the sheath dynamics caused by a time and space dependence of the mean electron energy is the main reason for a non-zero electron heating on time average. The dominant collisionless heating mechanism is ambipolar electron heating. Finally, the effects of plasma-surface interactions via secondary electron emission on the electron heating dynamics are studied by PIC/MCC simulations.