Tow-dimensional simulation of a pulsed-power electronegative discharge

A two-dimensional self-consistent fluid model was developed to study the sp atio-temporal dynamics of a pulsed power (square-wave modulated) inductivel y coupled electronegative (chlorine) discharge. The coupled equations for p lasma power deposition, electron temperature, and charged and neutral speci es densities were solved simultaneously to capture the spatio-temporal evol ution of the discharge. Simulation results showed separation of the plasma into an electronegative core and an electropositive edge during the active glow (power on) fraction of the cycle, and the formation of a positive ion/ negative ion (ion-ion) plasma in the afterglow (power off) fraction of the cycle. During the early active glow, the negative ion flux is convection do minated near the quartz window under the planar coil of the ICP reactor. Th is is due to the emergence of relatively large electrostatic fields, leadin g to a self-sharpening negative ion front propagating into the plasma.