CHARACTERIZATION OF A MICROWAVE PLASMA-JET CONTAINING AR-CH4 GAS-MIXTURE

This work is devoted to the study of the expansion of a Ar-CH4 microwa ve plasma. Diagnostics have been performed within the reactor using bo th an electrostatic Langmuir double probe and spatially resolved emiss ion spectroscopy. We have proven that the plasma jet results from elec tromagnetic surface wave propagation (n(e)>n(ec)=3.6 X 10(11) cm-3, T( e) approximately 23 000-46 000 K) and have shown that injection of met hane into the jet decreases n(e) and T(e), and thus limits the strikin g conditions. Such an expanding plasma finds applications in plasma en hanced chemical vapor deposition technology. It can be used to create simple radicals close to a substrate and thus limits their destruction on the reactor walls.