Control of Magnetic Moment in Uniaxial Anisotropy Magnetic Thin Film Taking Leakage Flux in RF Planar Spiral Inductors with Closed-Magnetic Core into Account

Abstract

A relation between high-frequency properties and an angle θ of anisotropy magnetic field in CoFeSiO/SiO₂ multilayer nano-granular magnetic film for an RF planar spiral inductor was described in order to suppress a leakage flux. A ferromagnetic resonance (FMR) frequency f_r and an FMR half-width Δf_r were very little dependence on θ. The FMR frequency f_r and the FMR half-width Δf_r were estimated about 2.5 and 0.3 [GHz]. On the other hand, the static permeability μ_s was dependent on approximately sin²θ. The static permeability in hard axis μ_h was estimated about 250. So then, the CoFeSiO/SiO₂ multilayer nano-granular magnetic film has superior high frequency character for the inductor.