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Temperature-stable NdFeB micromagnets with high-energy density compatible with CMOS back end of line technology

Published online by Cambridge University Press:  21 December 2015

Tim Reimer ,
Fabian Lofink ,
Thomas Lisec ,
Claas Thede ,
Steffen Chemnitz  and
Bernhard Wagner
Tim Reimer
Affiliation:
Fraunhofer Institute for Silicon Technology, Fraunhoferstraße 1, 25524 Itzehoe, Germany Institute for Electrical Engineering, University of Kiel, Kaiserstr. 2, 24143 Kiel, Germany
Fabian Lofink*
Affiliation:
Fraunhofer Institute for Silicon Technology, Fraunhoferstraße 1, 25524 Itzehoe, Germany
Thomas Lisec
Affiliation:
Fraunhofer Institute for Silicon Technology, Fraunhoferstraße 1, 25524 Itzehoe, Germany
Claas Thede
Affiliation:
Institute for Materials Science, University of Kiel, Kaiserstr. 2, 24143 Kiel, Germany
Steffen Chemnitz
Affiliation:
Fraunhofer Institute for Silicon Technology, Fraunhoferstraße 1, 25524 Itzehoe, Germany Institute for Electrical Engineering, University of Kiel, Kaiserstr. 2, 24143 Kiel, Germany
Bernhard Wagner
Affiliation:
Fraunhofer Institute for Silicon Technology, Fraunhoferstraße 1, 25524 Itzehoe, Germany Institute for Electrical Engineering, University of Kiel, Kaiserstr. 2, 24143 Kiel, Germany
*
*(Email: fabian.lofink@isit.fraunhofer.de)
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Abstract

The performance of a novel type of NdFeB micromagnets fabricated by agglomeration of magnetic powder by atomic layer deposition is investigated. The ALD-bonded micromagnets can withstand standard BEOL (back-end of line) processing and heat treatments at temperatures of up to 400 °C in air and vacuum without any significant impact on the demagnetization curves. By optimized packing density a remanence of 660 mT is realized for the micromagnets. The coercivity µ0Hc = 890 mT remains constant for all samples and corresponds to the powder value.

A comparison of the demagnetizing behavior of micromagnets with theory of solid body magnets prove that the influence of particle shape and hollow spaces on demagnetizing field is low. Hence, a similar impact of shape on stray field and forces as for solid body magnets can be assumed when integrating NdFeB ALD-bonded micromagnets in applications.

Keywords

magneticpowderferromagnetic
Type
Articles
Information
MRS Advances , Volume 1 , Issue 3: Nanomaterials and Synthesis , 2016 , pp. 209 - 213
Copyright
Copyright © Materials Research Society 2015 

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References

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