Iron oxide thin films prepared by ion beam induced chemical vapor deposition: Structural characterization by infrared spectroscopy

Iron oxide thin films as hematite (alpha-Fe2O3) have been prepared by ion b eam induced chemical vapor deposition. Very compact and dense films are obt ained by this procedure. The thin films have been grown by bombardment of t he substrate surfaces with O-2(+) ions or mixtures of O-2(+) and Ar+ ions, while a volatile precursor of iron [i.e., Fe(CO)(5)] is dosed onto the subs trate surface. In the latter case, Ar atoms are incorporated within the iro n oxide lattice. Atomic force microscopy, Rutherford backscattering spectro scopy, and x-ray photoelectron spectroscopy were utilized to characterize t he films' surface morphology, stoichiometry and chemical state. The film st ructure has been analyzed by grazing angle x-ray diffraction (XRD) and infr ared spectroscopies. In particular, infrared spectroscopy has permitted a t horough structural characterization of the films, even in the cases where X RD does not provide,information about the structure. Thus, when O-2(+) ions are used for the synthesis, iron oxide thin films grow with a hematite str ucture with the c axis of the crystallites perpendicular to the film surfac e. However, when an Ar+/O-2(+) ion mixture is used, the thin films have a h ematite structure with the c axis of the crystallites oriented parallel to the film surface. (C) 2000 American Vacuum Society. [S0734-2101(00)02605-1] .