ASSESSMENT OF SELF-CONSISTENT ANALYTIC MODEL FOR INDUCTIVE RF DISCHARGE AND DESIGN OF UNIFORM DISCHARGE WITH PLANAR-VERTICAL ANTENNAS

An RF discharge source with a vertical internal exciting coil was stud ied in OSRAM SYLVANIA recently [1]. Based on the self-consistent elect ron kinetic analysis presented in [2], a two-dimensional (2-D) (r, z) model is provided for this kind of inductively coupled discharge sourc e. The mode analysis solves the vector and scalar potentials of the el ectromagnetic (EM) fields, while the kinetic analysis gives the pertur bed Maxwellian distribution of electrons by solving the Boltzmann-Vlas ov equation, The vector potential of the EM fields, which dominates th e scalar potential in inductively coupled discharge, is calculated by considering the induced space currents obtained in terms of the electr on kinetic analysis, With closed-form solutions, the model provides a rigorous and fast way to compute the EM fields and electron kinetic be haviors in the sources, The theoretical results achieve good agreement with the measurements given in [1], Furthermore, in order to achieve a uniformly distributed plasma in the discharge chamber, which is desi red for plasma processing, we propose a novel discharge structure with both external planar coil and internal vertical coil excitions, For a few sets of parameters, the theoretical results demonstrate the impro ved uniformity for excited azimuthal E-fields in the chamber.