## 3 Results and Discussion
### Functional Characteristics of BC\({}_{x}\)N\({}_{y}\) Films
#### 3.4.3 Mechanical Properties  
The values of hardness and Young's modulus for LPCVD films obtained in the temperature range of 773-923 K do not change (Figure 12, Table 7) and slightly decrease when the temperature reaches 973 K. As seen from XPS data (Figure 8), these films are BC\({}_{\rm x}\)-like materials with high content of B-C bonds and very low nitrogen content. A decrease in hardness may be due to the appearance of an additional carbon phase, as can be seen from the Raman spectra. According to [97], the H and E of crystalline B\({}_{4}\)C are 25-40 GPa and 441-472 GPa, respectively. The hardness of LPCVD BC\({}_{\rm x}\)N\({}_{\rm y}\) films deposited using mixtures of TMAB + He and TMAB + NH\({}_{3}\) was 34 and 10-15 GPa, respectively [34]. The hardness of films, obtained in the same processes with the use of (C\({}_{2}\)H\({}_{5}\))\({}_{3}\)N\(\cdot\)BH\({}_{3}\) +N\({}_{2}\)+NH\({}_{3}\)[60] and B\({}_{3}\)N\({}_{3}\)H\({}_{3}\)(CH\({}_{3}\))\({}_{3}\) + C\({}_{6}\)H\({}_{5}\)CH\({}_{3}\) + NH\({}_{3}\) + N\({}_{2}\), was 12 and 20 GPa, respectively [98]. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{\(\mathbf{T_{dep},K}\)} & \multicolumn{2}{c}{**CA(H\({}_{2}\)O), \({}^{\circ}\)**} & \multicolumn{2}{c}{**CA(DEG), \({}^{\circ}\)**} & \multicolumn{2}{c}{**State**} & \multicolumn{2}{c}{**Owens-Wendt Method**} \\ \cline{2-9}  & \begin{tabular}{c} **Ellipse-** \\ **Fitting** \\ **Method** \\ \end{tabular}  & \begin{tabular}{c} **The Young-** \\ **[PERSON]** \\ **Algorithm** \\ \end{tabular}  & \begin{tabular}{c} **Ellipse-** \\ **Fitting** \\ **Method** \\ \end{tabular}  & \begin{tabular}{c} **The Young-** \\ **[PERSON]** \\ **Algorithm** \\ \end{tabular}  & \begin{tabular}{c} **Es, mN/m** \\ **Es, mN/m** \\ \end{tabular}  & \ \begin{tabular}{c} **Es, mN/m** \\ **Es\({}^{\rm d}\), mN/m** \\ \end{tabular}  & \begin{tabular}{c} **Es\({}^{\rm p}\), mN/m** \\ \end{tabular}  \\ \hline \multicolumn{9}{c}{LPCVD} \\ \hline
773 & 59 \(\pm\) 3 & 59 \(\pm\) 3 & 12 \(\pm\) 2 & 12 \(\pm\) 2 & 46 \(\pm\) 8 & 47 \(\pm\) 8 & 27 \(\pm\) 5 & 19 \(\pm\) 3 \\
823 & 59 \(\pm\) 5 & 60 \(\pm\) 4 & 10 \(\pm\) 2 & 10 \(\pm\) 2 & 46 \(\pm\) 10 & 47 \(\pm\) 10  
The elasticity index (H/E) is used to determine the elastic limit for surface contact [99]. The plasticity index (H\({}^{3}\)/E\({}^{2}\)) describes the material resistance to plastic deformation [100] and the fracture toughness of a thin solid film [99]. Therefore, these parameters are important for preventing wear. The coating with optimized H, H/E, and H\({}^{3}\)/E\({}^{2}\) values is expected to exhibit exceptional wear resistance. Figure 12b presents the temperature dependencies of elasticity and plasticity indexes of the LPCVD BC\({}_{x}\)N\({}_{y}\) films. The scratch adhesion test was employed to evaluate the degree of adherence between the BC\({}_{x}\)N\({}_{y}\) film and Si(100) substrate. The topology of scratch tracks was studied via an AFM mode of NanoScan-3D scanning nanohardness tester immediately after the scratching. It was observed that scratching the LPCVD samples (Figure 13) led to the formation of local fractures around the scratch's periphery at certain critical loads during the pyramidal tip test: L\({}_{c1}\) for the edge-forward orientation and L\({}_{c2}\) for the face-forward orientation. According to [101], different attack angles correspond to different deformation modes: the face-forward orientation is close to microcutting while the edge-forward orientation is closer to plastic extrusion. No significant exfoliation of the films from the substrates was observed. For films deposited at temperatures of 773-923 K, the values of L\({}_{c1}\) are 28-32 mN, and L\({}_{c2}\) are 21-26 mN (Figure 13f). For high-temperature film (T\({}_{dep}\) = 973 K), the values of L\({}_{c1}\) and L\({}_{c2}\) increase to 49 and 42 mN, respectively. It should be emphasized that among the studied films, these films have the highest adhesion to the Si(100) substrate.