Fabrication and magnetic properties of strip-patterned FeCoB-SiO2 nanoparticle films for GHz application

Highlights: • FeCoB-SiO₂ films were prepared by EFAD and thermal oxidization processing. • The patterned FeCoB-SiO₂ nanoparticle films have high stacking density. • The great GHz microwave performance is maintained in a wide SiO₂ volume fraction. -- Abstract: A series of high stacking density FeCoB-SiO₂ nanoparticle films with strip structures were prepared by electric field-assisted deposition technique attached by thermal oxidization processing. We obtained the expected soft magnetic properties for strip-patterned FeCoB-SiO₂ nanoparticle films. In this situation, relatively large permeability and high ferromagnetic resonance frequency are easily achieved in a wide gigahertz range. More importantly, the great GHz electromagnetic performance can be maintained in a wide SiO₂ volume fraction range by carefully controlling the width of SiO₂ strips. These results show that this kind of film materials have great potential for application in integrated devices operated in the gigahertz frequency range. Meanwhile, these single layer soft magnetic film materials with high permeability in the GHz range and high resistivity are easily merged into the micro manufacturing technology, such as CMOS and MEMS technique.