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 O 2 and N 2 gas flow rate. Fe-O-N films were deposited by reactive sputtering using O 2 and N 2 as reactive gas. The electrical resistivity of Fe-O-N films increased with increasing O 2 and N 2 gas flow rate. The resistivity increase with the O 2 flow rate was due to structure change from a mixed phase of metallic Fe+Fe 3 O 4 , to a mixed phase of FeO+¡-Fe 2 O 3 , and to a single phase of ¡-Fe 2 O 3 , as evidenced by XPS analysis of Fe 2p core excitation peaks. Meanwhile, the resistivity increase with the N 2 flow rate was due to structure change from a metallic Fe, to a mixed phase of metallic Keywords: iron oxide, nitrogen-doped, electrical resistivity, effects of oxygen and nitrogen flow rate

Thermal Analysis of Photoelectron Emission (PE) and X-ray Photoelectron Spectroscopy (XPS) Data for Iron Surfaces Scratched in Air, Water, and Liquid Organics

“…The shape of the Fe 2p spectrum at 25 • C obtained in our present experiment was very similar to that of the Fe 2p spectrum in the low-O 2 flow rate stage in the range of 705−725 eV as shown in Figure 3a in Reference [20], except for the shift in binding energy. In Reference [20], at higher O 2 flow rates, a mixed phase of FeO and α-Fe 2 O 3 with a satellite peak at 718.9 eV, and α-Fe 2 O 3 with a satellite peak at 719.2 eV were observed, respectively. Therefore, this suggests that the structure of the scratched surface at 25 • C may be composed predominantly of a mixed phase of metallic Fe and Fe 3 O 4 .…”

“…The XPS measurement was carried out after the PE measurement at 25, 200, and 339 • C for real iron surfaces scratched in the environments. Although we already reported the change of Fe 2p and Fe 3p spectra with the increasing temperature for the scratched samples [6], in the present study, according to References [15][16][17][18][19][20], we reexamined in more detail the dependence of Fe 2p spectra on temperature and scratching environments. The intensities and binding energies of peaks-called Peaks I, II, and III-observed in the Fe 2p spectra are listed in Table 1.…”

“…Ogawa et al [20] reported Fe 2p spectra of Fe−O−N films formed by sputtering iron metal at different O 2 flow rates (f O2 ) in an Ar−N 2 −O 2 gas mixture, and explained that the film structure with increasing O 2 flow rate changes from a mixed phase of metallic Fe and Fe 3 O 4 initially, to a mixed phase of FeO and α-Fe 2 O 3 , and finally, to α-Fe 2 O 3 . The shape of the Fe 2p spectrum at 25 • C obtained in our present experiment was very similar to that of the Fe 2p spectrum in the low-O 2 flow rate stage in the range of 705−725 eV as shown in Figure 3a in Reference [20], except for the shift in binding energy. In Reference [20], at higher O 2 flow rates, a mixed phase of FeO and α-Fe 2 O 3 with a satellite peak at 718.9 eV, and α-Fe 2 O 3 with a satellite peak at 719.2 eV were observed, respectively.…”

Influence of Oxygen Flow Rate on the Properties of FeOXNY Films Obtained by Magnetron Sputtering at High Nitrogen Pressure

“…This attributes a semiconductor behavior for these films. It is wellknown that α-Fe 2 O 3 (hematite) is a n-type semiconductor [37]. However, according to Morikawa et al and Ogawa et al [37,38], it can change to p-type conduction induced by N-doping in α-Fe 2 O 3 .…”

“…It is wellknown that α-Fe 2 O 3 (hematite) is a n-type semiconductor [37]. However, according to Morikawa et al and Ogawa et al [37,38], it can change to p-type conduction induced by N-doping in α-Fe 2 O 3 . Since we did not perform any hall effect measurements in this study, we can assume that our hematite-like films are of p-type.…”