@article{aa138a4b2d4546c597472a165e206845,
title = "Performance enhancement of on-chip inductors with permalloy magnetic rings",
abstract = "We demonstrate spiral inductors with continuous Permalloy ring structure at 100-μm scale, which achieve enhancements of sixfold in inductance and threefold in quality factor at frequencies as high as 200 MHz. The roll-off frequency is due to the eddy current loss in the conductive magnetic material. To reduce such loss and tune the permeability, the Permalloy film is laminated and split into bars. The dependence of the inductance and quality factor on permeability is further investigated. Different types of spiral inductors were fabricated with magnetic rings, helping shed light on optimization strategy.",
keywords = "Eddy current, Permalloy, ferromagnetic resonance, inductance density, lamination, magnetic ring, permeability, spiral inductor",
author = "Wei Xu and Saurabh Sinha and Tawab Dastagir and Hao Wu and Bertan Bakkaloglu and Gardner, {Donald S.} and Yu Cao and Hongbin Yu",
note = "Funding Information: Manuscript received September 17, 2010; revised September 30, 2010; accepted October 17, 2010. Date of publication December 10, 2010; date of current version December 27, 2010. This work was supported in part by the National Science Foundation under Grant 0727100. The review of this letter was arranged by Editor A. Z. Wang. W. Xu, S. Sinha, T. Dastagir, H. Wu, B. Bakkaloglu, Y. Cao, and H. Yu are with the School of Electrical, Computer, and Energy Engineering, Arizona State University Tempe, AZ 85287 USA (e-mail: yuhb@asu.edu). D. S. Gardner is with Intel Labs, Intel Corp., Santa Clara, CA 95052 USA. Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/LED.2010.2089779 Fig. 1. Optical images of the fabricated rectangular and square inductors. (a) Without NiFe (bare). (b) With NiFe thin film enclosed. (c) With patterned NiFe rings. (d) B–H magnetic hysteresis loop of 1-μm laminated NiFe film (50-nm NiFe/5-nm Cr) and layer thickness dependence of permeability measurement. Inset shows schematic of laminated NiFe film. (e) Process flow for on-chip inductor with NiFe.",
year = "2011",
month = jan,
doi = "10.1109/LED.2010.2089779",
language = "English (US)",
volume = "32",
pages = "69--71",
journal = "IEEE Electron Device Letters",
issn = "0741-3106",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "1",
}