Failure of exchange-biased low resistance magnetic tunneling junctions upon thermal treatment

J. H. Lee, H. D. Jeong, H. Kyung, Chong Seung Yoon, Chang Kyung Kim, B. G. Park, T. D. Lee

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Transmission electron microscopy (TEM) and Rutherford backscattering spectroscopy (RBS) were used to characterize low resistance (100-1000 μm2) tunneling junctions consisting of Ta/NiFe/Cu/NiFe/IrMn/CoFe/Al (6.6 and 7.7 Å)-oxide/CoFe/NiFe/Ta multilayers after annealing at temperatures ranging from 250 to 500°C. The Al (7.7 Å) junction showed continual improvement in the magnetoresistance (MR) ratio when annealed up to 300°C while the MR ratio of the Al (6.6 Å) junction dropped sharply above 250°C in spite of the only 1 Å difference in the deposited thickness of aluminum metal prior to plasma oxidation. TEM measurement provided evidence that the annealing process improves, in general, structural uniformity in the insulation layer, but thermal treatment can also degrade junction performance at a relatively low temperature due to current leakage through the electrodes. Current leakage can be problematic for a junction whose insulation barrier may be too thin (less than ∼10 Å). Both RBS and TEM analyses indicated that the maximum annealing temperature of exchange biased junctions lies between 400 and 500°C above which the multilayer structure in the pinned electrode is destroyed by interdiffusion.

Original languageEnglish
Pages (from-to)217-220
Number of pages4
JournalJournal of Applied Physics
Volume91
Issue number1
DOIs
StatePublished - 2002 Jan 1

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low resistance
insulation
transmission electron microscopy
annealing
backscattering
leakage
electrodes
spectroscopy
laminates
aluminum
oxidation
temperature
oxides
metals

Cite this

Lee, J. H. ; Jeong, H. D. ; Kyung, H. ; Yoon, Chong Seung ; Kim, Chang Kyung ; Park, B. G. ; Lee, T. D. / Failure of exchange-biased low resistance magnetic tunneling junctions upon thermal treatment. In: Journal of Applied Physics. 2002 ; Vol. 91, No. 1. pp. 217-220.
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Failure of exchange-biased low resistance magnetic tunneling junctions upon thermal treatment. / Lee, J. H.; Jeong, H. D.; Kyung, H.; Yoon, Chong Seung; Kim, Chang Kyung; Park, B. G.; Lee, T. D.

In: Journal of Applied Physics, Vol. 91, No. 1, 01.01.2002, p. 217-220.

Research output: Contribution to journalArticle

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