Hydrogen tracer diffusion was studied in amorphous SiC, Si0.66C0.33N1.33, and SiN1.33 films which were produced by radio-frequency magnetron reactive sputtering and which contained about 0.5at%H. The diffusion experiments were carried out between 700 and 1000C with ion-implanted deuterium tracer isotopes and secondary ion mass spectrometry. Effective diffusivities were derived which were nearly identical for all three types of material and which obey Arrhenius behaviours with activation energies of 3.0 to 3.4eV and pre-exponential factors of the order of 10-4 to 10-5m2/s. These results could be explained with a trap-limited diffusion mechanism of H where the tracer atoms were temporarily trapped by C and N dangling bonds, which had approximately the same binding energy to hydrogen.

Comparative Study of Trap-Limited Hydrogen Diffusion in Amorphous SiC, Si0.66C0.33N1.33 and SiN1.33 Films. H.Schmidt, G.Borchardt, U.Geckle, M.Bruns, H.Baumann: Journal of Physics - Condensed Matter, 2006, 18, 5363-70