Parallel-plate type holey-plate plasma source

Microwave plasma generated and sustained by evanescent waves emitted from a parallel-plate type source with a holey top plate is developed as a high-efficiency, lightweight, and low-cost plasma source. The plates have a 100 mm × 140 mm area and are separated by 10 mm. In an experiment, the entire body of the parallel plate is placed in a vacuum chamber. Dense plasmas are produced only on the holey plate. The electron density is 1 × 1010 cm-3 at an Ar gas pressure of 9 Pa and at a microwave power of 120 W at a 10 mm distance over the holey plate. The electron temperature is 3 eV. Uniformity is approximately ±22% within the area of the plate.