Effects of geometries on permeability spectra of CoTaZr magnetic cores for high frequency applications

The permeability of the magnetic core is closely related to the inductance improvement for integrated inductors. Simulation data indicate that the effective permeability of the finite-sized magnetic core can be significantly reduced from the relative permeability of the magnetic material due to the demagnetization effect. The observed trend in the permeability of the patterned CoTaZr magnetic cores, however, shows that the demagnetization effect alone is not sufficient to predict the effective permeability and that the magnetic domain patterns need to be considered as well. The measured permeability was found to decrease as the patterned magnetic core was narrowed or shortened.