Structure and property of epitaxial titanium oxynitride grown on MgO(001) substrate by pulsed laser deposition

High-quality epitaxial TiNxOy films with different oxygen content were deposited on MgO(001) substrates by pulsed laser deposition method. The chemical composition of the deposited films was determined by X-ray photoelectron spectroscopy. X-ray diffraction results showed that the TiNxOy films are heteroepitaxially grown on MgO with good crystallinity and their lattice parameters decrease with increased oxygen concentration. Transmission electron microscopy analyses showed that TiNO films contain a low density of dislocations. Atomic force microscopy revealed very smooth surfaces of TiNxOy films with roughness of 0.26–0.29 nm. The resistivity of TiNxOy films determined by Hall measurement was about 28–33 μΩ cm. Nanoindentation measurements showed the film hardness and Youngʹs modulus of about 23–26 GPa and 400–430 GPa, respectively.