Mechanical properties of amorphous carbon nitride films synthesized by electron cyclotron resonance microwave plasma chemical vapor deposition

Amorphous carbon nitride films have been deposited on silicon using electron cyclotron resonance microwave plasma chemical vapor deposition with radiofrequency substrate bias. The films were measured by Auger electron spectroscopy, atomic force microscopy, nanoindentation, and nanoscratch test. The studies revealed that the hardness and surface roughness decreased with increasing nitrogen content in the films. These were due to the formation of sp² graphite clusters and carbon-nitrogen triple bonds in the carbon network. We demonstrate that hydrogen surface treatment can reduce the friction coefficient in nanoscratch tests.