Optimization of tunneling magnetotransport and thermal properties in magnetic tunnel junctions by rapid thermal anneal

K. I. Leea, K. H. Chaea, J. H. Leea, J. G. Hab, K. Rhiec, W. Y. LeeCorresponding Author Contact Information, E-mail The Corresponding Author, d and K. H. Shina

a Nano Device Research Center, Korea Institute of Science and Technology, P.O. Box 131, Seoul 136-792, South Korea
b Department of Electronic Materials Engineering, Kwangwoon University, Seoul 139-050, South Korea
c Department of Physics, Korea University, Seochang, Chungnam 339-700, South Korea
d Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-Dong, Seoul 120-749, South Korea

Available online 14 June 2003.


Abstract

We report on a systematic investigation of rapid thermal anneal (RTA) effects on the properties of FeMn exchange-biased magnetic tunnel junctions (MTJs). The tunneling magnetoresistance (TMR) in an as-grown MTJ is found to be ~27%, whereas the TMR in MTJs annealed by RTA increases with annealing temperature up to 300 °C, reaching ~46%. A significant change in the effective barrier thickness (teff) and height (capital Phi, Greekeff) occurs within 10 s during RTA. Transmission electron microscopy and X-ray reflectivity studies demonstrate that the interface of the alumina tunnel barrier for the MTJ annealed by RTA became sharper and clearer, giving rise to the enhanced TMR.

Author Keywords: Magnetic tunnel junctions (MTJs); Magnetic random access memory (MRAM); Rapid thermal anneal (RTA)


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