Structural and nanoindentation studies of epitaxial titanium oxynitride (001) films grown on MgO(001) substrate

• The lattice parameters and residual strain/stress of TiNxOy films decrease as oxygen concentration increases.
• The hardness (H) and Young's modulus (E) of TiNxOy films are about 17–26 GPa and 355–430 GPa, respectively.
• H and E of TiNxOy films decrease with increasing oxygen content and increase with increasing nitrogen content.
• H and E of TiNxOy films decrease with decreasing residual compressive stress.

We investigate the effect of chemical composition and residual stress on the mechanical properties of high-quality epitaxial TiNxOy films deposited on MgO(001) substrates by using nanoindentation. The lattice parameters and residual strain/stress of TiNxOy films decrease as oxygen concentration increases. Hardness and Young's modulus determined by nanoindentation are about 17–26 GPa and 355–430 GPa, respectively, which vary with chemical composition and residual stress.