Analytical calculation for estimation of magnetic film properties for a 3-GHz thin film inductor

Thickness, resistivity, and the Gilbert damping constant are estimated using Maxwell and Landau-Lifshitz-Gilbert (LLG) equations to meet operating parameters of ferromagnetic thin film inductors in the gigahertz frequency range. The following properties of soft magnetic film are calculated to satisfy a quality factor of 10 at 3 GHz: 4/spl pi/M/sub S/=21.3 kG; H/sub k/=215 Oe; and /spl mu//sub dc/'=100. The complex permeability was not influenced by film thickness up to 100 nm. Operation frequency increases with the increase of electrical resistivity and decrease of film thickness. The Gilbert damping constant is found to have a significant effect on the operation frequency. The quality factor can be retained up to 3GHz for 100-nm-thick film with a damping constant of 0.015 when resistivity is greater than 50 /spl mu//spl Omega//spl middot/cm.