EXPERIMENTAL AND THEORETICAL-STUDIES OF A PULSED MICROWAVE EXCITED ARCF4 PLASMA/

The present work deals with a pulsed microwave discharge in an Ar/CF4 gas mixture under a low pressure (1-10 mbar). The discharge chamber de veloped has a cylindrical geometry with a coupling window alternativel y made of quartz or alumina. The setup allows one to investigate the p lasma-wall interactions (here etching of the quartz window) and the ig nition process of the pulsed microwave plasma. Microwave pulses with a a duration of 50-200 mu s and repetition rate between 1 and 10 kHz ar e typical for the experiments. The space-time behavior of the fluorine number density in the discharge has been investigated experimentally by optical actinometry. The discharge kinetics is modeled using electr on-transport parameter sand rate coefficients derived from solutions o f the Boltzmann equation. Together with the solution of the continuity and electron balance equations and the rate equations describing the production of CFx(x = 2, 3, 4) radicals and F atoms, a good agreement between experimental and theoretical data can be achieved.