A Novel Fabrication and Properties Investigation of Permalloy-SiO2 Granular Films with Induced Anisotropy

Permalloy-SiO2 (PS) granular films with various metallic volume fraction (xV) have been fabricated by non-continuum multilayer alternate sputtering with different power to generate appropriate controllable anisotropy and control the microstructure precisely. Transmission Electron Microscopy (TEM) investigation shows that the PS granular films consist of Permalloy crystalline nano-sized granules embedded in amorphous SiO2 matrix. The films exhibit excellent soft magnetic properties and high resistivity because of the unique microstructure and composition variety, both of which have been controlled by adjusting the preparation conditions. Soft magnetic properties of the films are improved with increasing metallic xV and sputtering power, while resistivity of the films goes down with increasing xV and sputtering power. Furthermore, the controllable anisotropy generated in alternated sputtering process is applicable to integrated planar magnetic inductor which operates in the range of Radio Frequency (RF) for device performance enhancement.