Diagnostics of inductively coupled chlorine plasmas: Measurement of electron and total positive ion densities

This work is part of a broader study that creates a set of experimentally m easured chlorine plasma parameters (electron and gas temperatures, electron energy distribution function, electron density, densities of ion fractions , and total ion density). This set is obtained over a broad range of operat ing conditions (1-20 mTorr, 5-1000 W) of an inductively coupled plasma. In this part, we present the electron (n(e)) and total positive ion (n(i)(+)=n (Cl2)(+)+n(Cl)(+)) densities. n(e) and n(i)(+) were measured with a Langmui r probe across the diameter or in the middle of the reactor. Line integrate d values of n(e) were independently obtained with microwave interferometry, and converted into the spatially resolved data using the Langmuir probe n( e) profiles. Finally, a method is presented for measuring relative positive ion densities, based on optical emission at 7504 Angstrom from trace amoun ts of Ar. (C) 2001 American Institute of Physics.