Effects of O2 and N2 flow rate on the electrical properties of Fe-O-N thin films

Abstract

We report the dependence of electrical properties of Fe-O-N thin films on the deposition condition as well as on O2 and N2 gas flow rate. Fe-O-N films were deposited by reactive sputtering using O2 and N2 as reactive gas. The electrical resistivity of Fe-O-N films increased with increasing O2 and N2 gas flow rate. The resistivity increase with the O2 flow rate was due to structure change from a mixed phase of metallic Fe+Fe3O4, to a mixed phase of FeO+α-Fe2O3, and to a single phase of α-Fe2O3, as evidenced by XPS analysis of Fe 2p core excitation peaks. Meanwhile, the resistivity increase with the N2 flow rate was due to structure change from a metallic Fe, to a mixed phase of metallic Fe+Fe3O4, and to a single phase of Fe3O4.