Two-dimensional electrical modeling of asymmetric radio-frequency discharges for geometry effect analysis. Comparison with experiments

A self-consistent two-dimensional particle model coupled to the external ci rcuit equations was developed in an asymmetrical configuration for the self -bias voltage calculation and the reactor design study. An intermediate mod eling was performed in one and two symmetrical geometries. The one-dimensio nal model is used to optimize the computing time which is reduced by a fact or of 10 by using some optimization techniques. It is also used to validate the charged particle and basic data choices. We have shown that the consid eration of only two charged particle species (electron and H-3(+) positive ion) is sufficient in the present hydrogen radio-frequency discharge modeli ng. Computational results (i.e., power density and self-bias voltage) are i n good agreement with experimental results. A strong gradient of the plasma parameters (such as electric field, potential, charged particle densities and energies) was observed in the periphery of the driven electrode. Furthe rmore, the present two-dimensional asymmetric model shows that the interele ctrode distance increase (from 1.7 up to 3.7 cm) can lead to reducing the p lasma heterogeneity due to the geometrical electric field. (C) 2001 America n Institute of Physics.