Fabrication and Comparison of Broad-band Inductors with One and Two Co-based Amorphous Ground Planes

Abstract

To address the growing need for smaller integrated passive components, inductors were fabricated with magnetic material on silicon using a standard silicon processing tool set. CoZr based alloys were targeted due to their soft magnetic properties, high crystallization temperature and compatibility with fabrication facilities. The best results measured were from inductors which exhibited -60% increase in inductance for a single layer of 1.0μm of CoTaZr. Sandwiched inductors with 0.41μm of CoTaZr above and below the planar spiral show enhancement of -100%. Inductors with CoNbZr were also fabricated, however, the magnetic properties degraded during high temperature processing. Finally, the effective permeability of the CoTaZr inductors was estimated to be-85-150 depending on the device geometry.