Fractal growth of Fe-N thin films prepared by magnetron sputtering at elevated temperature

Fe-N thin films were prepared by direction-current magnetron sputtering with different process parameters. The surface morphology and fractal dimension of the films have been studied using atomic force microscopy and small angle X-ray scattering techniques. The results indicate that the surfaces of thin films exhibit an obviously self-affine fractal characteristic, and the fractal dimension is greatly affected by the N2/Ar flow rate ratio. When the N2/Ar flow rate ratio is less than 1/6, the film growth follows the KPZ growth model. Contrarily, the growth mechanism of the film is agreement with the DLCA model.