Control of magnetic flux and eddy currents in magnetic films for on-chip radio frequency inductors: Role of the magnetic vias

In this paper, the role of the magnetic vias for magnetic flux and eddy current control is investigated using both simulations and experiments that used different patterning techniques and by altering the magnetic via width. Improved finger-shaped magnetic vias have been designed and integrated into on-chip radio frequency inductors improving the peak quality factor from 400MHz to 800MHz without sacrificing the inductance enhancement. The eddy currents and magnetic flux density in different areas of the magnetic vias are analyzed by 3D electromagnetic simulation. With optimized magnetic vias, the high frequency response of up to 2GHz has been achieved.