## 5 Conclusions
(f) The XRD patterns in obtained from sample C60, (@-20) scan, in the interval 20 = (20-40)\({}^{\circ}\) used for determination of the crystal grain size. The reflection used corresponds to d\({}_{(111)}\) = 2.5103 A [4] and the grain size is about 6.0 nm. Table S1: Chemical composition of the thin films as determined by XPS survey studies for samples C3, O3, C5, O5, O20, O60, C90, and O90. Figure S3: (a) Deconvolution of the C 1s line of sample O20. (b) Deconvolution of the C 1s line of sample O60. (c) Deconvolution of the C 1s line of sample O90; (d) Deconvolution of the C 1s line of sample C90. Figure S4: (a) Deconvolution of the Si 2p line of sample O20. (b) Deconvolution of the Si 2p line of sample O60. (c) Deconvolution of the Si 2p line of sample O90. (d) Deconvolution of the Si 2p line of sample C90. Figure S5: (a) GDOES study of O5 at different points of the specimen. The figure shows the results that differ the most, marked as O5_1 and O5_2 as well as the mass concentration of Si (blue traces), and C and O (black and red traces, respectively). (b) GDOES study of C20 specimen. The mass concentration of Si, C, and O is presented by blue, black and red traces, respectively. (c) GDOES study of O5 sample at depth interval 40-120 nm: the mass concentration of Si is drawn by blue trace, while those of C and O are drawn by black and red traces, respectively. (d) GDOES study of C90 sample at depth interval 40-120 nm: the mass concentration of Si is drawn by blue trace, while those of C and O are drawn by black and red traces, respectively. Figure S6: TEM images obtained from O20 specimen: (a) a low magnification TEM and the corresponding SAED images (inset) obtained from O20 specimen. (b) HRTEM image indicating the presence of different phases in the studied specimen. Figure S7: TEM images obtained from O90 specimen: (a) a low magnification TEM and the corresponding SAED images (inset) obtained from O90 specimen. (b) HRTEM image indicating the presence of single SiC phase. Figure S8: Raman spectra of C90 (red trace) and Si(111) substrate (black trace). Inset: Raman spectrum of the thin film (sample C90) obtained by subtracting the Raman spectrum of the bare Si(111) substrate from the spectrum of C90 specimen. Conceptualization, T.M. ; Methodology, T.M. ; Validation, T.M. and S.K. ; Investigation, T.M., V.M., P.R., I.A., I.Z., G.A., D.K. ([PERSON]), B.G., P.T., K.K., B.B., S.K., D.D., D.K. ([PERSON]) and D.K. ([PERSON]); Writing--original draft, T.M. and I.A. ; Writing--review & editing, T.M., I.A., D.K. ([PERSON]) and V.P. ; Supervision, T.M. and V.P. ; Project administration, T.M. ; Funding acquisition, T.M. All authors have read and agreed to the published version of the manuscript. The authors gratefully acknowledge financial support from the National Science Fund of Bulgaria under Grant KP-06-H58/2-16.11.2021. This work was also supported by the European Regional Development Fund under the \"Research Innovation and Digitization for Smart Transformation\" program 2021-2027 under Project BG16 RFP002-1.014-0006 \"National Centre of Excellence Mechatronics and Clean Technologies\". Research equipment of the Distributed Research Infrastructure INFRAMAT, part of the Bulgarian National Roadmap for Research Infrastructures, supported by Bulgarian Ministry of Education and Science was used in this investigation. Data is contained within the article. The authors declare no conflicts of interest. The following abbreviations are used in this manuscript: \begin{tabular}{l l} PVD & Physical Vapor Deposition \\ CVD & Chemical Vapor Deposition \\ UHSS & Ultra-High Strength Steel \\ XPS & X-ray Photoelectron spectroscopy \\ GDOES & Glow Discharge Optical Emission Spectroscopy \\ XRD & X-ray Diffraction \\ GIXRD & Grazing Incidence X-ray diffraction \\ TEM & Transmission Electron Microscopy \\ HRTEM & High-Resolution Transmission Electron Microscopy \\ SAED & Selected Area Electron Diffraction \\ \end{tabular}