Aspect ratio dependent saturation field in patterned amorphous Co-Zr-Ta-B thin films with uniaxial anisotropy

The saturation field of patterned amorphous Co-Zr-Ta-B films is adjusted by using shape anisotropy in patterned magnetic thin films for inductors. The relationship between aspect ratio and saturation field which is essential for achieving high saturation current in magnetic inductors is investigated. By changing the aspect ratio of patterned films, the in-plane easy and hard axes induced during film deposition gradually decrease and then change direction as the aspect ratio is changed, which is also verified by numerically calculating the demagnetizing field in the films. It is shown that the saturation field of inductors with patterned Co-Zr-Ta-B films can be changed thus, providing a pathway towards high saturation current in high power density applications such as voltage regulators.