Computer-aided design of microwave plasma sources: Potential and applications

The electrical behavior of SLAN (slot antenna) plasma sources is analysed with the Maxwell equations finite integration algorithm (MAFIA). The influence of the source components and their dimensions on resonance frequencies and power coupling of all eigenmodes up to 3 GHz is studied. Resonances close to the excitation frequency may adversely influence the power absorption in the source. By shifting the frequencies of these resonances the source performance call be optimized. As an example the azimuthal plasma homogeneity of a SLAN microwave plasma source is improved by a proper design. To be more realistic the plasma has been introduced into the simulation as a lossy dielectric. Although this is a crude approach, the results yield useful insights into the local power absorption.