High frequency (GHz) and low resistance integrated inductors using magnetic materials

Integrated microinductors using magnetic materials were fabricated with cutoff frequencies over 3 GHz. Magnetic materials are typically not used in high-frequency inductors because their frequency range has been limited to <100 MHz. The high-frequency magnetic film, amorphous CoZrTa, was integrated into standard silicon process technology. Inductors consume large amounts of chip area, but with magnetic materials, the inductors can be made smaller thereby reducing their capacitance and resistance. A novel 3-dimensional structure for reducing the inductor´s resistance by an order of magnitude was also developed. Simulations of inductors with magnetics and measurements are presented.