Investigation of energetic electrons in a 915 MHz microwave discharge produced in Ar

The electrical field distribution and plasma parameters in the vicinity of the quartz plate of a 915 MHz microwave discharge are measured using Langmuir probe, thermal probe and microwave field antenna. Energetic electrons with energies exceeding 15 eV are observed at locations of high microwave field that are correlated with high temperatures by thermal probe and high effective electron temperature.

Plasma parameters show a spatial dependence in the skin depth while are almost uniform in plasma volume. Present results confirm that the kinetic of the energetic electrons is strongly related to the complex distribution of the microwave electric filed near the dielectric. Measurements are performed in Ar for different pressures and discharge powers.