Evaluation of an end-feed, loop coupled, compact microwave plasma source

Summary form only given. This paper investigates the operation and performance of the end feed, compact ECR plasma source and compares the operation with earlier side feed excited designs. The plasma source investigated in this paper consists of a microwave applicator, quartz discharge chamber, and ECR magnet array. The microwave applicator is a cylindrical stainless steel microwave cavity, of 9.8 cm inner diameter. The cavity is internally tuned, with two degrees of freedom, by the adjustment of: 1) a sliding short, and 2) either an adjustable end feed loop or an adjustable end feed probe. Output variables measured were: absorbed power vs. cavity tuning, spatial electric field patterns, and Langmuir probe measured electron density and temperate. Comparisons of these output variables are made between: 1) the probe coupled side-feed source, 2) the new loop coupled end-feed configuration, and 3) the new probe coupled end-feed configuration. An equivalent circuit representing the electromagnetic characteristics of this source is also derived.