EFFECTS OF NONLOCAL ELECTRON KINETICS AND TRANSITION FROM ALPHA-REGIME TO GAMMA-REGIME IN AN RF CAPACITIVE DISCHARGE IN NITROGEN

The electron kinetics and regime of operation of asymmetrically couple d RF (27-MHz) nitrogen discharges in two vessels with different intere lectrode gaps over the range of 0.20-0.35 torr gas pressure are studie d in terms of the electron energy distribution function (EEDF). The la tter is measured by means of a computer-controlled data acquisition sy stem, a Langmuir probe with cross-modulation second derivative techniq ue applied. The experiments are performed with an axial resolution alo ng the RF electric field and accompanied with a measurement of electri cal discharge characteristics. The effects of local and nonlocal plasm a response are considered. The transition between alpha and gamma disc harge regimes is registered by measuring the EEDF and its moments' cha nges with the increase of the RF discharge current density.