Langmuir probes are commonly used to measure electron density and temperature in the low temperature and low density plasmas used in plasma processing, although the plasma conditions are sometimes not ideal for such measurements. We report measurements of the perturbing effect of such probes in the high magnetic field region of an electron cyclotron resonance discharge by making Thomson scattering measurements of electron temperature and density under normal operating conditions and also in the presence of a probe. The results revealed that the probe clearly qualitatively changed the plasma. An attempt to quantify this change appeared to indicate that the effect of the probe was to decrease the electron density and increase the electron temperature in the vicinity of the probe.

This content is only available via PDF.
You do not currently have access to this content.