Micromachined inductor integrated with a patterned soft magnetic thin film

This study demonstrates a novel design and fabrication process to realize micromachined inductor integrated with the patterned soft magnetic film. Highly resistive (CoFeB)(SiO₂) films as soft magnetic films were patterned and deposited by lift-off process and sputtering technique, respectively. In order to enhance inductor´s inductance and find out the major design parameters, three types of the inductors integrated with the patterned soft magnetic films were designed, fabricated and tested. The spiral type inductor was fabricated by copper electroplating. This novel approach integrates inductors with soft magnetic thin films by evaporating the nitride film as dielectric and protection layer. As a result, the influence of the soft magnetic film contributes 10 % increase in the inductance on “magnetic film aligned” inductor at 2 GHz.