Electron Temperature Evolution in a Low-Pressure Dusty RF Nitrogen-Rich Methane Plasma

Particles are generated in a classical planar RF (13.56-MHz) reactor in nitrogen-rich methane at low pressure (120 Pa). The gas decomposition leads to particle generation and growth. During their formation, the particles become negatively charged. The electrical and the optical parameters of the discharge are disturbed. The presence of particles in the plasma is put in evidence by laser light scattering and is correlated to the DC self-bias voltage. A small quantity of argon is introduced in the gas mixture in order to estimate the electron temperature. The temporal evolutions of both the electron temperature and the optical emission intensities of excited argon are correlated with the particle growth and behavior in the plasma.