X-ray diffraction study of TiN coatings sputtered at different substrate temperatures

Microstructure evolution in TiN films reactively sputtered on steel substrates was investigated by X-ray diffraction. Systematic changes of lattice parameters, texture, internal strain, and macrostress with increasing nitrogen flow into the magnetron deposition chamber were studied for the samples deposited at two different substrate temperatures (150 and 400 °C), and non-monotonic dependences were found for all the quantities. A preferred orientation of the 〈111〉 type for substoichiometric samples is changed to the strong 〈110〉 texture at high nitrogen flow. The largest microhardness was observed for the strongly substoichiometric and very defective films. A marked anisotropy of X-ray line broadening and lattice parameters was found for these samples. The influence of the higher substrate temperature on microstructure of the films is small for all the measured quantities at the deposition rate used (0.06–0.2 μm · min⁻¹).