Quantitative analysis of hydrogen in amorphous films of hydrogenated carbon nitride

The amorphous phase of hydrogenated carbon nitride, a-CNx:H (0 less than or equal to x less than or equal to 1), films may have clusters consisting of a mixture of sp(2)- and sp(3)-hybridized materials with cluster sizes of 0.2-2 nm. The hydrogen termination limits the size of the carbon and carbon nitride clusters. It also influences the mechanical properties of the sample. In this experiment, the relationship between the hydrogen content and the mechanical properties of carbon and related materials was investigated using elastic recoil detection analysis (ERDA), nanoindentation techniques and Raman spectroscopy. The samples were classified into three categories of hardness: mechanically soft a-CNx:H (hardness: 1-8 GPa), mechanically hard a-CNx:H (8-30 GPU) and hard hydrogenated amorphous carbon (a-C:H) (more than 30 GPa). The hydrogen contents of the sample were 10-50 at.%, 5-40 at.%, and less than 3 at.% for soft a-CNx:H, hard a-CNx:H and hard a-C:H, respectively.