Double layer onset inside the near-electrode sheath of a RF capacitive discharge in oxygen

This paper reports the axial profiles of the electron temperature Te in the RF capacitive discharge in oxygen recorded with a probe technique. We observed the Te peaks near the boundaries of the sheaths as well as inside the near-electrode sheath. The Te peak inside the sheath is, probably, due to the formation of the double layer at the anode phase of this near-electrode sheath. The assumption of a double layer formation is also supported by the photos of the sheath glow making evident the bright region inside the sheath. The results of our measurements agree with our fluid simulation satisfactorily.