Effect of Positive-Ion Temperature in the Sheaths Surrounding Cylindrical and Spherical Probes in Electronegative Plasmas

This paper analyzes the effect of positive-ion temperature on the sheath that surrounds a cylindrical or spherical probe in an electronegative plasma. We developed a theoretical model that considers a hydrodynamic approach for positive-ion motion. In order to introduce the positive-ion temperature into the model, we consider that positive ions flow adiabatically toward the probe. This model allows us to obtain the electrical potential profile surrounding the probe and the current-to-voltage characteristic curves. These $I$–$V$ curves were fitted as functions of the probe radius, the probe biasing potential, and the positive-ion temperature. Finally, these expressions allow us to obtain the floating potential of the probe for different electronegativities and positive-ion temperatures.