Approach to form planar structures based on epitaxial Fe1−xSix films grown on Si(111)

• Published in: Thin solid films Vol. 642; pp. 20 - 24
• Main Authors: Tarasov, A.S., Lukyanenko, A.V., Tarasov, I.A., Bondarev, I.A., Smolyarova, T.E., Kosyrev, N.N., Komarov, V.A., Yakovlev, I.A., Volochaev, M.N., Solovyov, L.A., Shemukhin, A.A., Varnakov, S.N., Ovchinnikov, S.G., Patrin, G.S., Volkov, N.V.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.11.2017
• Subjects: Iron silicides; MOKE microscopy; Planar structures; Wet etching; Planar structures; Wet etching; MOKE microscopy; Iron silicides
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2017.09.025

An approach to form planar structures based on ferromagnetic Fe1−xSix films is presented. Epitaxial Fe1−xSix iron‑silicon alloy films with different silicon content (x=0–0.4) were grown on Si(111) substrates. Structural in situ and ex situ characterization of the films obtained was made by X-ray diffraction, reflective high-energy electron diffraction, Rutherford backscattering spectrometry and transmission electron microscopy, which confirmed single crystallinity and interface abruptness for all films. Etching rates in the wet etchant (HF: HNO3: H2O=1: 2: 400) for the films with various chemical composition were obtained. A nonmonotonic dependence of the etching rate on silicon content with a maximum for the composition Fe0.92Si0.08 was discovered. Moreover, the etching process is vertical and selective in the etching solution, i.e., the etching process takes place only in silicide film and does not affect substrate. As an example, a four-terminal planar structure was made of Fe0.75Si0.25/Si(111) structure using the etching rate obtained for this silicon content. Magneto-optical Kerr effect (MOKE) microscopy and transport properties characterization indicated successful etching process. •An approach to form planar structures based on Fe1−xSix films is presented.•The silicon content in the epitaxial Fe{1−x}Si{x} films varies in the wide range.•A nonmonotonic dependence of the etching rate on the silicon content was observed.•A process of wet chemical etching is presented for the creation of planar structures.