XPS study of polycrystalline and epitaxial FeTaN films deposited by d.c. reactive magnetron sputtering

Thin films of FeTaN have been investigated as potential head materials for several years. However, little information related to its chemical characteristics can be found in the literature, therefore polycrystalline and epitaxial FeTaN films were synthesized by d.c. reactive magnetron sputtering. Follow-up annealing was performed on some of the thin films under vacuum conditions. The chemical compositions and elemental chemical states of both kinds of thin films were investigated by x-ray photoelectron spectroscopy. It is shown that the nitrogen content in the films can be changed and easily controlled by varying the nitrogen gas flow rates during the deposition process. There are no large chemical shifts in the binding energies of Ta 4f, Fe 2p and N 1s between polycrystalline and epitaxial films. No chemical compounds among Fe, Ta and N were formed in as-deposited or even in vacuum-annealed thin films. However, a chemical shift of Ta 4f from its atomic state was found. In addition, relatively large contents of carbon and oxygen inside the films were noticed. The existing chemical states, sources and possible effects of nitrogen, carbon and oxygen on the magnetic properties were studied and discussed.