Dust particle formation in a low pressure CH4-N2 radio-frequency (13.56 MHz) plasma.

Polymer-like hydrogenated amorphous carbon nitride (a-CNx:H) nanoparticles are observed in a CH4(50 %)/N-2(50 %) rf plasma. SEM micrographs show that the dust particles are spherical with diameters in the range 0.2-1.1 mum for rf powers in the range 40-120 W. They are trapped in the plasma bulk volume. The absorption spectra of the a-CNx:H particles reveal the presence of C-H, C=N and Cequivalent toN bonds. The absorption peak intensities strongly depend on the incident rf power. The Cequivalent toN triple bonds increase with the rf power whereas the C-H bonds decrease.