## 3 Results
It should be noted here that prolonged sputtering will lead to a significant increase in the information depth and to a decrease in resolution due to surface roughening. In a compound material such as SiC, the silicon atoms are more rapidly removed than the carbon atoms. Thus, the Si/C ratio may be observed close to 1/3 instead of the expected 1/1 [32]. A significant result of these studies is the established diffusion of oxygen and carbon atoms as silicon oxide with variable composition and as Si-O-C ensembles in the regions near the surface of Si substrates. The in-depth distribution of Si, C, and O in the films was investigated via the GDOES method using the Spectrum Analytic GDA 750 HR. The depth profiles were measured in RF mode (constant voltage, regulated pressure) with the optimized parameters: Si-C (800 V, 3 hPa). After an evacuation period of 30 s, the sample surface was flushed with the analytical gas (Ar 99.999%) for 30 s. The results for some of the characterized samples are shown in Figures 5a,b and 55a-d. Here, we must point out the following:  
* Due to the removal of material from the thin films by a directed plasma flow, a significant predominance of Si atoms sputtered from the SiC as a part from the thin film is expected compared to those of carbon. * The elemental analysis in the GDOES method refers to the atoms sputtered from the sample surface, while in the depth-dependent concentration profiles, the solid phase (unsputtered) of the samples is analyzed, and in this sense, the two methods, when analyzing identical samples, give a picture as close as possible to the real one. The mass concentration distribution of Si, C, and O in the depth of the thin films clearly shows that there is no clearly defined interface between the thin film and the substrate. However, we can assume that the thin film begins at the sample surface and extends approximately to the point where the carbon concentration decreases by 2-4% from its maximum, while the silicon concentration increases correspondingly. Based on this, the approximate thickness of the thin films is 4-5 nm for samples C3 and O3, 5-6 nm for C5 and O5, around 7 nm for C20 and O20, 9-10 nm for C60 and O60, and 12-13 nm for C90 and O90. Additionally, in the samples from which the native oxide has not been properly removed, (i) the concentration of the main components varies within large limits at different points on the surface of the thin films as shown in Figure 4a for sample O60; (ii) in the region in which there is a close to constant distribution of Si and C, the concentration of SiC is significantly lower than its corresponding value for the samples with properly removed native oxide. Figure 4: (**a**) The in-depth distribution of C-containing species in sample O3 according to the deconvolution of the C 1s line. (**b**) The in-depth distribution of C-containing species in sample O5 according to the deconvolution of the C 1s line. (**c**) The in-depth distribution of Si-containing species in sample O3 according to the deconvolution of the Si 2p line. (**d**) The in-depth distribution of Si-containing species in sample O5 according to the deconvolution of the Si 2p line. (**e**) The in-depth distribution of O-containing species in the sample O3 according to the deconvolution of the O 1s line. (**f**) The in-depth distribution of O-containing species in sample O3 according to the deconvolution of the O 1s line. The samples for TEM examinations were prepared by mechanically scratching the surface of the samples with a UHSS blade. A suspension in double-distilled water was prepared from the separated flakes, and the resulting colloid was collected by dropping and drying the drops on a FORMVAR-covered copper mesh. The results of the TEM-examined samples (Figures 6a,d, 7a,c, 8a,b, 9a-c, 56a,b and S7a,b) show that the thin films consist of mixed nanocrystalline and amorphous masses in different ratios, and in general, with increasing synthesis time, well-ordered nanocrystals predominate.