On-Chip Thin Film Inductor for High Frequency DC-DC Power Conversion Applications

In this paper, we are reporting the design, fabrication and characterization of on-chip solenoid inductors with novel magnetic thin-film core for high frequency DC-DC power conversion application. Our CMOS - BEOL process compatible micro-inductor fabricated shows a high L/Rdc up to 440 nH/Q due to a thick Cu winding, as well as a high inductance density of 440 nH/mm
²
and high Q factor of 14.5 at 10 MHz which results from inclusion of laminated Co-based magnetic core which is amorphous and shows very good soft magnetic properties. The on-chip magnetic-film inductor technology is targeted at applications that enable high frequency (>10 MHz) DC-DC power conversion.