Anisotropy Field and Core Loss of Highly Resistive (CoFeB)-(SiO_2) Films

摘要

Highly resistive (CoFeB)-(SiO_2) films were deposited on glass substrates by conventional rf-cosputtering as thin-film cores for micro power devices.The effects of annealing on the magnetic properties and resistivity were investigated, and showed a possibility of controlling the permeability and core loss of the films by induced anisotropy. The films exhibited low coercivities of 0.2-0.5 Oe, together with high resistivities of about 400 #mu# #OMEGA# cm and high relative permeability of more than 1000. The core loss of the films was about 1.5 J/m~3 at 1 MHz for a maximum flux density of B_m = 0.1 T. The films have good potential for use as thin film cores.