Correlation of heat treatment and structural, optical, and electrical properties of titanium nitride thin layers

TiN thin films are prepared by the DC magnetron sputtering method, and the effect of post annealing treatment on the physical, structural, morphological, and optical properties of TiN layers are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and UV-VIS spectrophotometer. Variation of electrical resistivity and film’s hardness are also investigated. Based on the XRD results, increasing annealing temperature would not change film’s stoichiometry, but deteriorates improvement of the films crystalline quality. The as-deposited film with amorphous structure changes to a single-phase crystalline structure that has a preferred orientation along (۱۱۱) and the polycrystalline structure at higher annealing temperatures. According to SEM images, a dense structure transforms to a denuded zone structure during annealing temperature. The reflectance of TiN films shows a minimum in the visible region indicating a significant increase in the infrared region. The optical band gap energy value increases by increasing the annealing temperature while, the electrical resistivity and hardness values decrease.