Magnetic Multilayer Films for Microwave Filter Application

摘要

The on-chip integration of microwave passive components is an important issue for electronic industry. The use of magnetic thin films in place of bulk materials is the solution to integrate these components[1,2]. Hence, it is important to know the electromagnetic properties of magnetic thin film and multilayer (ML) structures in the microwave range. Network Analyzer based ferromagnetic resonance (NA-FMR) [1,2] technique was used to measure the stop-band frequencies (f{sub}(res)) of the magnetic structures. The aim of the present investigation is to significantly boost the operating frequency of the devices in very low applied magnetic field. To do this, we performed two sets of experiments: (1) Introduction of additional exchange anisotropy [3] by layering of ferromagnetic (FM) and antiferromagnetic (AFM) layers ([NiO/NiFe]{sup}n) in comparison to single NiFe film [shown in Fig.1]. (2) Like exchange anisotropy, the FMR frequency also shifts upward due to interlayer exchange coupling arises due to interaction of two FM layers separated by a non-magnetic spacer layer (Fe/Si/Fe) [shown in Fig.2].