Structure and composition of silicon carbide films synthesized by ion implantation

The mathematical decomposition of the IR absorption spectrum obtained from a Si layer after the C$^+$ ion implantation with an energy of 10 or 40 keV or from a homogeneous SiC$_{0.7}$ film has demonstrated that fractions of weak elongated Si–C bonds in the amorphous phase, strong shortened Si–C bonds on the surface of small nanocrystals, and tetrahedral Si–C bonds in the crystalline phase (degree of crystallinity) after high-temperature annealing (1250–1400$^\circ$C) of the layers are equal to 29/29/42, 22/7/71, and 21/31/48%, respectively. A system of SiC$_{2.0}$, SiO$_2$, SiC$_{0.8}$, and SiC$_{0.6}$ layers in the film on the Si substrate has been identified using X-ray reflectometry and the simulation with the Release software. The reflectometry data on fluctuations of the intensity of X-ray reflections in the region of the main maximum have been interpreted in terms of variations in the density over the depth of the layer with a Gaussian distribution of carbon atoms from 2.55 and 2.90 g/cm$^3$ for the SiC$_{0.25}$ and SiC$_{0.65}$ layers, respectively, to 3.29 g/cm$^3$ for the SiC$_{1.36}$ layer.