Chemical Sputtering of Carbon Films by Low Energy N2+ Ion Bombardment

In this paper the first experimental evidence for the effect of chemical sputtering of a growing carbon film by nitrogen ion bombardament is reported. The investigation was performed in a carbon sputter deposition facility by using N2+ions of 150 eV. At this low energy physical sputter effects can be neglected. For the gas analysis a highly sensitive quadrupole mass analyser was used. The evolution of the one or more volatile compounds giving rise to lines with a mass/charge film. Simultaneously film etching was monitored. The etching rate was estimated to be about 0.5 carbon atoms per incident N2+ ion. The experimental results suggest that this etching effect is primarily due to the formation of a CN radical. If this radical is formed at the surface it reacts with hydrogen and water adsorbates to form compounds such as HCN and OHCN. If it is formed in subsurface layers of the carbon film it can recombine with another CN radical forming then a C2N2 molecule.

GISSLER Wolfram; 

1996-04-15

JRC12797

https://publications.jrc.ec.europa.eu/repository/handle/JRC12797,