Multilayer Ferromagnetic Composites Enabling On-Chip Magnetic-Core Inductors Beyond 1 Ghz

This paper reports of fabricated unpatterned ferromagnetic NiFe/AlN multilayer composites and an established process flow for magnetic core material suitable for integration with Silex 3D RF TSV technology. The fabricated single-loop test inductors achieved an inductance enhancement of 4.8 and a quality factor enhancement of 4.5 at 400 MHz. Simulations show that magnetic material in connection with 3D TSV inductors result in an inductance enhancement up to a factor of 5 at GHz frequencies for the same inductor area or the same inductance can be achieved at 9 times smaller area and cost.