Closed magnetic circuit structure for RF integrated spiral inductor

This paper studies the microfabrication process and the experimental demonstration of a closed magnetic circuit type GHz-drive integrated spiral inductors, consisting of a stack of 0.2-μm-thick RF-sputter deposited CoNbZr, RF-sputter deposited SiO₃, 3-μm-thick electrodeposited Cu coil, SiO₃ with surface planarization, and 0.2-μm-thick RF-sputter deposited CoNbZr. Main idea is to establish the fabrication process of such a sophisticated microstructure and to demonstrate as high quality factor as possible for the possible practical near-future applications. The structure of the closed magnetic circuit type inductor discussed in this paper.