Effect of Irradiation Atmospheres on the Film Growth of Iron Oxide on Si Substrate by Ion Beam Sputter Deposition Method

Abstract

Fe₃O₄ thin films of approximately 30 nm in thickness were grown on Si substrate at 573 K by means of ion beam sputter deposition (IBSD) technique, using oxygen or argon ions to sputter Fe₃O₄ solid target. The effect of these irradiation atmospheres on the chemical composition and crystallinity of the thin films was investigated using XPS (X-ray Photoelectron Spectroscopy), RHEED (Reflection High-Energy Electron Diffraction), and XRD (X-Ray Diffraction). We revealed that the oxygen atmosphere improves the crystallinity of the film as compared with argon atmosphere, but also causes the formation of iron oxide phases other than Fe₃O₄. On the other hand, the obtained results for Fe₃O₄ thin films prepared in argon atmosphere had poor crystallinity. Furthermore, the results of RHEED suggested that the preferential growth orientations of the film are different depending on the irradiation atmospheres.