Ultrahigh frequency properties of discontinuous CoFeB/SiO2
multilayer films with high resistivity
multilayer films with high resistivity
(Department of Electronic Science and Technology, Huazhong University of Science and Technology,
Wuhan 430074, China)
Wuhan 430074, China)
Abstract: A series of multilayers of Co36Fe46B18/SiO2 were fabricated by DC/RF magnetron sputtering, and further post-annealed in vacuum magnetic field at 200℃ for 2 h. The results show that the microstructures and electromagnetic properties of Co36Fe46B18/SiO2 multilayer films can be altered by varying the thickness of CoFeB and the process of annealing. High permeability along with high magnetic loss in the GHz frequency range is achieved in the optimized discontinuous multilayer films. Both real and imaginary parts of the complex permeability are larger than 260 at 1.6 GHz for this film, and the resistivity is as high as 1.4 mΩ∙cm. The discontinuous Co36Fe46B18/SiO2 multilayers are supposed to serve as the microwave absorbers and EMI shielding materials in GHz range.
Key words: CoFeB/SiO2; discontinuous multilayer; high frequency; permeability; resistivity