SELF-CONSISTENT FLUID MODELING OF RADIO-FREQUENCY DISCHARGES IN 2 DIMENSIONS

Results from a two-dimensional (2D) fluid simulation of a parallel plate, capacitively coupled radio frequency discharge bounded by a cylindrical insulator with a grounded exterior surface are presented. We find that the radial sheath at the insulator focuses current into the plasma region adjacent to the sheath. This 2D effect has important ramifications for the ionization rate, which peaks sharply in the metal-insulator corners. We have experimentally observed the enhancement of the emission rate in a comer using spatially resolved optical emission spectroscopy. A ''thick'' insulator yields radial profiles for the time-averaged plasma density and potential that are essentially uniform. A ''thin'' insulator, however, results in an off-axis maximum in the plasma density and potential due to the comer ionization.