Effect of nitrogen partial pressure and temperature on RF sputtered Fe–N films

Obtaining a Fe16N2 ordered nitride (α″) film has been an interest of both scientists and technologists since it was first discovered to exhibit magnetization as great as 310 emu/g. Although single phase α″ films have been formed by epitaxial growth, it is still difficult to produce a polycrystalline single phase α″ film. In order to evaluate its potential as magnetic recording media and in magnetic recording head, more detailed research is required to study the favorable conditions for the formation and to manipulate the microstructure of this metastable phase in thin films. In the present work, efforts have been made to sputter deposit iron nitride thin films at various nitrogen–argon flow rate ratios and substrate temperatures. Depositions were carried out on Si(1 0 0) substrates using diode type magnetron radio frequency sputtering. The phase compositions, microstructural features and thickness of the resultant films were determined by X-ray diffraction analysis, scanning electron microscopy and atomic force microscopy. Attempts have been made to correlate the observed phase compositions and microstructures with the deposition conditions.