Low-temperature preparation of FeNx and Fe/FeNx multilayer by electron shower

In the presence of a substrate bias (>-100 V), FeNx films were prepared at a low temperature by the electron shower method. The nitride content was increased with increasing Nz gas pressure and the structure of the films was changed as: Fe --> Fe4N --> Fe-3 --> Fe2N. Multilayer films of (Fe + Fe4N)/(Fe4N + Fe3N) and Fe/Fe3N were prepared on glass and poly ethylene terephthalate (PET) substrates, respectively, in the presence of a pulse of the substrate bias. By the pulse of the electron shower, the Fe/Fe4N and Fe/Fe3N multilayer films were prepared on glass and PET, respectively. When the gas pressure was increased from 7 x 10(-3) Torr to 11 x 10(-3) Torr, Fe/Fe2N films were prepared on both the substrates. The concentration (1 at.%) of N in these Fe layers prepared by the pulse of the electron shower was lower than that (7 at.%) prepared by the pulsed bias. Multilayer films were prepared from a single vapor source by these methods.