Integrated RF On-Chip Inductors With Patterned Co-Zr-Ta-B Films

Integrated on-chip inductors with boron-incorporated amorphous Co-Zr-Ta-B films for reducing the size of the inductor and increasing the quality factor are presented. A 3.5-fold increase in inductance and a 3.9-fold increase in quality factor over inductors without magnetic films are measured at frequencies as high as 1 GHz. The Co-Zr-Ta-B films are patterned into the shape of fingers in the magnetic via region to improve the on-chip inductors, high frequency response. Compared with nonpatterned films, finger-shaped magnetic vias result in at least a 30% increase in quality factor in the gigahertz range. It is also demonstrated that by using laminations, an up to 9.1X inductance increase with good frequency response up to 2 GHz can be achieved.