Effect of post-annealing on ultra-high frequency properties of amorphous Fe-Co-B thin films

Abstract

In this paper, FeCoB amorphous thin films were deposited on glass substrates using a triode sputtering source under a uniform applied magnetic field. The as-deposited films exhibit a low coercivity of 1.7 Oe, a high anisotropy field of 37 Oe and 4 17.5 kG, when sputtered with a bias voltage of 180 V. The large anisotropy fields and saturations in these films result in a ferromagnetic resonance frequency as high as 2.63 GHz, a relative permeability of 400-500 and a low dissipation of 10-30 in the frequency range of 0.1-1 GHz. Upon subsequent annealing at 200-400 C for 2 hrs, the magnetic properties of the films are found to be affected significantly. The magnetic properties of the as-deposited and the annealed films have been compared with a considering of the microstructure modification during annealing.Index Terms-UHF properties, soft magnetic properties, amorphous magnetic thin films, Fe-Co-B alloys.

Analytical Calculation for Estimation of Magnetic Film Properties for a 3-GHz Thin Film Inductor

“…FeCrTaN [1], [2] and amorphous FeCoB [3] films have recently been shown to have excellent soft magnetic properties. The real and imaginary parts of permeability for FeCrTaN were found to be about 340 and 30, respectively, up to 1 GHz and the FMR frequency was about 3 GHz.…”

Magnetic properties and high frequency characteristic of obliquely sputtered Co–M (M=V and Nb) thin films

“…Up to now, several techniques have been employed to increase H k of the films, including post-annealing of the film in a magnetic field [7,8], changing the sputtering oblique angle [9][10][11], depositing multilayers [12,13], doping transition metals [14,15], composition modification [16,17] and so on. Nevertheless, post-annealing may affect other components of the whole circuit, and the thickness and interface in the multilayer films are not easy to be precisely controlled.…”

Electric field modulation of magnetic anisotropy and microwave absorption properties in Fe50Ni50/Teflon composite films

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