Crystalline Orientation and Perpendicular Magnetic Anisotropy of Iron Oxide Thin Films Deposited by Target Facing Type Sputtering

Opposed-target sputtering is employed to produce Fe3O4 single-phase films with (111) orientation on glass substrates and ZnO-coated silicon wafers. The magnetostriction values of these films were larger than those of randomly oriented films, which caused the film to have a large perpendicular magnetic anisotropy. Low pressure during sputtering improved the (111) orientation, but also increased the perpendicular magnetic anisotropy. Attempts to make (111) oriented films on A1 substrates failed, but those made on the ZnO-coated silicon wafers showed epitaxial growth and good reproducibility.