Influence of nitrogen flow rates on iron nitride thin films prepared by DC reactive magnetron sputtering

Iron nitride (FeN) thin films were deposited on silicon wafer substrates by dc reactive magnetron sputtering techniques. The FeN thin films were prepared at the fixed substrate temperature 200°C under different nitrogen flow rates. The crystal structures, physical morphologies, and surface roughness of the prepared FeN thin films were characterized by the grazing-incident X-ray diffraction (GIXRD), field-emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM), respectively. From the results, the GIXRD patterns indicated the change in the film orientations from ξ-Fe2N to γ”-FeN along with the increased nitrogen flow rates. In addition, the FE-SEM micrographs demonstrated the decrease of the FeN film thickness. The effects of the nitrogen flow rates towards the crystallinity, the physical morphology, and surface roughness of the thin films were investigated and discussed.