Experimental characterization of capacitively coupled radio-frequency discharge in N2-CH4

We have performed extensive measurements in capacitively coupled radio-frequency discharges, producing N2-CH4 plasmas for methane concentrations between 0% and 10%. These dusty plasmas are well characterized by monitoring the evolution, with the methane concentration, of the electron density, the self-bias voltage, the coupled power, and the spectral line intensity of a number of optical transitions. The plasma properties exhibit drastic changes that are found correlated with the dust production regime.Fundação para a Ciência e a Tecnologia (FCT) - PICS Cooperation Program, financed by the Portuguese FCT and the French CNRS. A. Mahjoub thanks the ANR program (ANR-09-JCJC-0038 contract) for a post-doctoral position.CNRS - ANR program (ANR-09-JCJC-0038 contract