Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-24T09:54:45.386Z Has data issue: false hasContentIssue false
  • English
  • Français

Temperature-stable NdFeB micromagnets with high-energy densitycompatible 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: [email protected])
Get access

Abstract

The performance of a novel type of NdFeB micromagnets fabricated by agglomerationof magnetic powder by atomic layer deposition is investigated. The ALD-bondedmicromagnets can withstand standard BEOL (back-end of line) processing and heattreatments at temperatures of up to 400 °C in air and vacuum withoutany significant impact on the demagnetization curves. By optimized packingdensity a remanence of 660 mT is realized for the micromagnets. The coercivityµ0Hc = 890 mT remains constant forall samples and corresponds to the powder value.

A comparison of the demagnetizing behavior of micromagnets with theory of solidbody magnets prove that the influence of particle shape and hollow spaces ondemagnetizing field is low. Hence, a similar impact of shape on stray field andforces as for solid body magnets can be assumed when integrating NdFeBALD-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 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Zhang, Q. and Kim, E. S., “Micromachined Energy-Harvester stack with enhanced electromagnetic Induction through vertical Integration of Magnets”, J. of microelectromech. syst. 24(2), 384–394 (2014).Google Scholar
Pallapa, M. and Yeow, J.T.W., “A review of the hybrid techniques for the fabrication of hard magnetic microactuators based on bonded magnetic powders” , Smart Mater. Struct . 24, 025007 (2015).Google Scholar
Je, S.-S., Wang, N., Brown, H. C., Arnold, D. P., and Chae, J., “An electromagnetically actuated microspeaker with fully-integrated wax-bonded Nd-Fe-B micromagnets for hearing aid applications” , Proc: Transducers , Denver, USA, (2009).Google Scholar
Oniku, O. D. and Arnold, D. P., “High-Energy-Density Permanent Micromagnets formed from heterogeneous magnetic powder mixtures” , Proc: MEMS 2012 , Paris, FRANCE, (2012).Google Scholar
Wang, N.: “Fabrication and Integration of permanent magnet materials into MEMS transducers” , Dissertation , University of Florida, (2010).Google Scholar
Arnold, D. P., Wang, N., “Permanent Magnets for MEMS” , J. Microelectromech. Syst . 18(6), 1255–1266 (2009).Google Scholar
Gerngross, M.-D., Chemnitz, S., Wagner, B., Carstensen, J., and Föll, H., “Ultra-high aspect ratio Ni nanowires in single-crystalline InP membranes as multiferroic composite” , Phys. Status Solidi RRL 7, 352–354 (2013).Google Scholar
Aharoni, A., “Demagnetizing factors for rectangular ferromagnetic prisms” , J. Appl. Phys . 83(6), 3432 (1998).Google Scholar
Pivinskii, Y.. E., “Increasing the density of particle packing in forming ceramics” , translated from: Steklo I Keramika 9, 25–29 (1969).Google Scholar
Cygan, D.F. and McNallan, M.J., “Corrosion of NdFeB permanent magnets in humid environments at temperatures up to 150°C” , J. Magn. Magn. Mater . 139, 131–138 (1995).Google Scholar