Langmuir probe measurements in inductively coupled CF4 plasmas

Abstract The characteristics of low-pressure inductively coupled CF 4 plasmas have been investigated using a Langmuir probe. The electrons gain energy through the collisionless heating mechanism. In addition, the plasma has two electron populations: low temperature population of electrons with high density, and high temperature population of electrons with low density. With the increase of radio-frequency input power, the former temperature T ce , the latter temperature T he , and mean electron temperature T e decrease, while their densities n ce , n he , n e increase. This phenomenon has been explained by the thermodynamic equilibrium of the collision between the electrons and radicals in the plasma.