Bonding structure and mechanical properties of carbon nitride bilayer films with Ti and TiN interlayer

摘要

Carbon nitride (CN_x) bilayer films with Ti and TiN interlayer were synthesized by cathode arc technique at various nitrogen pressures (P_(N2)). The dependences of microstructure and bonding composition of the films on the P_(N2) and interlayer were analyzed by Raman spectroscopy and X-ray photoelectron spectroscopy. Microstructure evolution consisting of the ordering and size of Csp~2 clusters, the faction of N–sp~3/N–sp~2 bonds and graphite-like/pyridine-like configurations was dominated by P_(N2), interlayer and annealing. The results showed that Ti and TiN interlayer decrease the atomic ratio of N/C and increase clustering Csp~2. High P_(N2) induces the formation of C ≡N and C-N bonds, the increase of sp~2-bonding content and the growth of Csp~2 clusters. A large part of nitrogen atoms are coordinated with sp~2-hybridized carbon (minimum 71% for annealed CN_x monolayer). TiN/CNx bilayer had a higher content of pyridine-like configuration. Morphological characteristics of CN_x monolayer and bilayer mainly depend on the surface character (roughness and surface energy) of the sublayer. The internal stress in the as-deposited Ti/CN_x bilayer is smaller, but it after annealing is higher than that of CN_x monolayer and TiN/CN_x bilayer. These results may be of interest for studying the CN_x films with controlled bonding composition and expected engineering properties.