On-Chip Thin Film Inductor for High Frequency DC-DC Power Conversion Applications
S. Lawrence Selvaraj, Martin Haug, Chor Shu Cheng, Dragan Dinulovic, Lulu Peng, Khaled El Shafey, Zishan Ali, Mahmoud Shousha, Yong Chau Ng, Nur Aziz Yosokumoro, Lothar Lehmann, Marcel Wieland
Abstract
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 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 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.