Abstract
In the communication industry, miniaturization is highly required for inductor devices. In order to miniature the dimension of inductors, high inductance is necessary. For this purpose, to employ high-permeability magnetic films enhances the inductance of inductors. For high-permeability, in-plane uniaxial anisotropy is a critical demand. The FeCoHfAlO/AlO <sub>x</sub> multilayered films were fabricated by dc reactive magnetron sputtering. Due to the insertion of AlO <sub>x</sub> layers, the out-of-plane uniaxial anisotropy of the FeCoHfAlO magnetic films is reduced and their resistivity is also raised. Therefore, the permeability of the FeCoHfAlO/AlO <sub>x</sub> multilayers will be increased further. With the optimum configuration of a seven-layer structure [FeCoHfAlO (171 nm)/AlO <sub>x</sub> (10 nm)] <sub>7</sub> , high resistivity (ρ ~ 7490 μΩcm) and high-permeability (μ′ > 90 at 30-50 MHz) were obtained. The permeability increased nearly ten times from 9 (3 layers) to 98 (7 layers). © 2010 Elsevier B.V. All rights reserved.