Microstructure evolution of ZrN films annealed in vacuum

Microstructure changes of ZrN films deposited onto Si substrates by unbalanced magnetron sputtering were investigated over temperatures of 200–1100 °C in vacuum. The microstructure and morphology of the films were investigated by means of X-ray diffraction and field-emission scanning electron microscopy. The residual stress was determined using a laser scanning curvature measurement method. Neither color change nor oxides could be discerned over the whole investigated temperature. Scarce round micro-blisters, due to the increase of residual compressive stress in the films, were found above 400 °C. The texture coefficient, lattice parameter, and average strain of the films varied with annealing temperature. The measured residual stresses reached a minimum, i.e., − 7.0 GPa at 400 °C. Subsequently, the stress relaxed with temperature and became tensile at 1000 °C. Additionally, the Young's Modulus of the films could be obtained from the residual stress and average strain relation. The evaluated value was 380 ± 70 GPa, which is comparable to those reported from the literature; nevertheless, this technique is nondestructive and much simpler.