SIMS analysis of carbon-containing materials: content of carbon atoms in $sp^{2}$ and $sp^{3}$ hybridization states

A new approach to the analysis of carbon-containing materials by the method of secondary ion mass spectrometry is studied, which allows one to determine the concentration of carbon atoms in the states of $sp^{2}$ and $sp^{3}$ hybridization. It is proposed to use the ratio of the intensities of cluster secondary ions C$_{8}$/C$_{7}$ as the main parameter of the mass spectra of secondary ions characterizing the concentration of $N(sp^{3})$. From measurements of several test structures, a calibration dependence of $N(sp^{3})$ on the C$_{8}$/C$_{7}$ ratio was obtained. The $N(sp^{3})$ profiles of diamond-like carbon samples grown on diamond and silicon substrates were measured, showing an $N(sp^{3})$ concentration of 0.3 to 0.6 for different growth modes and an inhomogeneous distribution of the $N(sp^{3})$ concentration over the thickness of the samples.