Temperature-stable NdFeB micromagnets with high-energy density compatible with CMOS back end of line technology. Issue 3 (2016)

• Record Type: Journal Article
• Authors: Reimer, Tim; Lofink, Fabian; Lisec, Thomas; Thede, Claas; Chemnitz, Steffen; Wagner, Bernhard
• Is Part Of: MRS advances. Volume 1:Issue 3(2016)
• Page Start: 209
• Page End: 213
• Publication Date: 2016
• Subjects: magnetic, -- powder, -- ferromagnetic; Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/adv.2015.19
• Languages: English
• ISSNs: 2059-8521

Abstract

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 µ0 Hc = 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.