IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Plasma Science Monday Sessions
       Session PS-MoP

Paper PS-MoP22
Analysis of Chlorine-Containing Plasmas

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Plasma Diagnostics and Plasma-Surface Interactions Poster Session
Presenter: G.F. Franz, Infineon Corp., Germany
Correspondent: Click to Email
Capacitively coupled discharges of strongly reactive atmospheres containing mixtures of boron trichloride and chlorine are investigated employing impedance measurements, Langmuir probe measurements, optical emission spectroscopy (OES), and self-excited electron resonance spectroscopy (SEERS). The analysis covers the whole area spanned by these gases (including some mixtures), discharge pressure and RF power over more than one order of magnitude, and their impact on important plasma parameters like plasma density, plasma potential, electron temperature, temperature of the plasma bulk, electron collision rate with neutrals, and actual RF power coupled into the discharge. From these, other properties (electrical conductivity, capacitance, plasma bulk resistance, sheath resistance and its thickness) can be derived. Since the methods are partially complementary, a mutual control of the obtained data is made possible, and the limits of the methods can be evaluated. Compared to discharges of inert gases, which are used as calibration standard, electron plasma density and electron temperature are both definitely lower, which is mainly caused by electron attachment of the electronegative molecules. Absolutely no chlorine ions could be found in the plasma which is referred rather to the effective cooling of the Cl-containing species than to the nonexistence of these species. Furthermore, we compared values for the electron temperature and the plasma density obtained with OES and SEERS, respectively, and with the Langmuir-probe system. The concordance in both properties is surprisingly good, despite the fact that the electron energy distribution should be described with two temperatures and only Langmuir is spatially resolved. The variation of the calculated dc conductivity either from impedance measurements or combined Langmuir/SEERS lies within a factor of 2 and is mainly referred to uncertainties of the current path rather than to principal faults of the various methods.