Abstract
High permeability magnetic films can enhance the inductance of thin-film inductors in DC-DC converters. In order to obtain high permeability, effective uniaxial anisotropic field should be as low as possible. A multilayered technique (laminating the magnetic layers with oxide spacers) was exploited to improve the magnetic properties of thick films. The FeCoHfO/AlO x multilayered films were fabricated by dc reactive magnetron sputtering. Inserting an insulator (AlO x ) layer can decrease the magneto-elastic anisotropy by reducing the residual stress of the FeCoHfO magnetic films. The anisotropic field and resistivity of the FeCoHfO/AlO x multilayered films were evidently improved by multilayered coating. With this optimum configuration of 9 layers structure [FeCoHfO (133 nm)/AlO x (10 nm)] 9 , low anisotropic field (H K = 65 Oe) and high resistivity (ρ ∼ 1350) μΩ cm were achieved.