Measurement of the sheath surrounding a planar electron emitting surface in the afterglow of an RF plasma

Summary form only given. The potential of a sheath surrounding a planar, electron emitting cathode was measured in the afterglow of a capacitively coupled RF plasma. Using Langmuir and emissive probes, the electron temperature and plasma potential were measured as a function of time. The inflection point in the limit of zero emission, a highly accurate emissive probe technique to measure the plasma potential, was used to make time resolved measurements for the first time. Measurements showed that as the plasma electron temperature cooled, approaching the emitted electron temperature, the emissive sheath potential shrank to zero. These results were in good qualitative agreement with a new theory of emissive sheaths, but deviations at intermediate temperature ratios indicate that the behavior of the emissive sheath is not yet fully understood.

The potential of a sheath surrounding a planar, electron emitting cathode was measured in the afterglow of a capacitively coupled RF plasma. Using Langmuir and emissive probes, the electron temperature and plasma potential were measured as a function of time. The inflection point in the limit of zero emission, a highly accurate emissive probe technique to measure the plasma potential, was used to make time resolved measurements for the first time. Measurements showed that as the plasma electron temperature cooled, approaching the emitted electron temperature, the emissive sheath potential shrank to zero. These results were in good qualitative agreement with a new theory of emissive sheaths, but deviations at intermediate temperature ratios indicate that the behavior of the emissive sheath is not yet fully understood.