Effect of high annealing temperature on giant tunnel magnetoresistance ratio of CoFeB/MgO/CoFeB magnetic tunnel junctions

J. Hayakawa, S. Ikeda, Y. M. Lee, F. Matsukura, H. Ohno

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183 Citations (Scopus)

Abstract

The authors report tunnel magnetoresistance (TMR) ratios as high as 472% at room temperature and 804% at 5 K in pseudo-spin-valve (PSV) CoFeBMgOCoFeB magnetic tunnel junctions (MTJs) annealed at 450 °C, which is approaching the theoretically predicted value. By contrast, the TMR ratios for exchange-biased (EB) SV MTJs with a MnIr antiferromagnetic layer are found to drop when they are annealed at 450 °C. Energy dispersive x-ray analysis shows that annealing at 450 °C induces interdiffusion of Mn and Ru atoms into the MgO barrier and ferromagnetic layers in EB-SV MTJs. Mechanisms behind the different annealing behaviors are discussed.

Original languageEnglish
Article number232510
JournalApplied Physics Letters
Volume89
Issue number23
DOIs
Publication statusPublished - 2006

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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