Summary: The generation of particles in a CH4/N2 radio‐frequency discharge has been studied in order to understand the effect of nitrogen incorporation into the particles. The nitrogen increase in the gas mixture leads to a modification of the particle behaviour in the plasma bulk. Moreover, for nitrogen ratios higher than 50%, changes in particle morphology and texture are observed. These modifications may be explained by the appearance of new radicals like CN evidenced, thanks to optical emission spectroscopy (OES). Moreover, the evolution of CH and CN emission lines has been studied. On the other hand, IR analyses have shown the presence of CN, NH, CH bonds in the particles and in the coatings. Their proportions depend on the nitrogen flow rate. A correlation between OES results and IR analyses has been established.

Particles are generated in low pressure radio frequency ͑13.56 MHz͒ CH 4 / N 2 discharges containing 90% of nitrogen. The influence of the radio frequency power supply on the particle presence within the plasma is studied. Particles are evidenced by laser light scattering. The particle formation leads to modifications in the discharge electrical parameters such as the dc self-bias voltage and the phase angle third harmonic. The plasma is analyzed by optical emission spectroscopy by following the temporal evolution of excited species such as CN, N 2 , N 2 + , Ar, and He. Finally, the particle morphology and size are analyzed by scanning electron microscopy. The correlation between these results allows a better understanding of the power influence on the particle growth within the plasma.

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