Dynamic scaling phenomena and universality classes in growth of iron nitride thin films deposited by direct current magnetron sputtering

In this paper, dynamic scaling approach has been used to investigate the growth of iron nitride films, which were deposited by direct current magnetron sputtering using an Ar/N2 gas mixture (N2/(N2 + Ar) = 30%) at room temperature and 250 °C substrate temperature. The structure of the deposited films was determined by using X-ray diffraction. The perpendicular fluctuations in the height h (x, t) of the surface were analyzed by atomic force microscopy and grazing incidence X-ray scattering in the light of dynamical scaling approach, and the two dependent nontrivial exponents, roughness exponent α and growth exponent β, were determined. For the iron nitride films grown at room temperature and 250 °C, α = 0.39 ± 0.01 and 0.30 ± 0.02 and β = 0.29 ± 0.03 and 0.28 ± 0.07, respectively, which were in agreement with a type of universality that was suggested by Kardar, Parisi and Zhang. It might be concluded that it was desorption rather than the surface diffusion that dominated the relaxation process in both the case of room and higher substrate temperatures for the deposition of iron nitride thin films.