Langmuir probe measurements in inductively coupled CF4 plasmas

The characteristics of low-pressure inductively coupled CF4 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 Tce, the latter temperature The, and mean electron temperature Te decrease, while their densities nce, nhe, ne increase. This phenomenon has been explained by the thermodynamic equilibrium of the collision between the electrons and radicals in the plasma.