Improvement in Resonant Frequency of Magnetic Domain Wall Displacement in Soft Magnetic Thin Films by Slit Patterning

摘要

Soft magnetic thin films have the potential to enable reduction of the dimensions of inductors and high-frequency modules. However, the permeability in the magnetic easy axis direction in thin films with uniaxial anisotropy is too low to use in the MHz range owing to a resonance of magnetic domain wall displacement. In the case of spiral inductors using magnetic films with uniaxial anisotropy, since both easy and hard axes in the films are excited, the low permeability in the easy axis direction in the MHz range reduces the inductance of the devices. To improve the characteristics of magnetic thin-film inductors in the MHz range, it is important to control magnetic domain wall displacement and increase its resonant frequency in the magnetic easy axis direction. To control magnetic domain wall displacement in the magnetic easy axis direction, we fabricate a magnetic wire array by slit patterning perpendicular to the magnetic easy axis in CoZrTa thin films. We also discuss the effect of wire width on magnetic characteristics. Furthermore, we analyze the effect of the slit patterning on magnetic domain wall displacement using a motion equation of the magnetic domain wall.