Atomic-scale spectroscopic imaging of CoFeB/Mg-B-O/CoFeB magnetic tunnel junctions

Journal Article · Mon Jul 20 00:00:00 EDT 2009 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3184766· OSTI ID:21294196

Cha, J J; Huang, P Y; Tseng, H W; Li, Y; Buhrman, R A; Muller, D A ^[1]; Read, J C ^[2]; Egelhoff, Jr, W F ^[3]

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1. School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853 (United States)
2. Department of Physics, Cornell University, Ithaca, New York 14853 (United States)
3. Magnetic Materials Group, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)

Atomic-scale electron spectroscopic imaging on sputtered magnetic tunnel junctions (MTJs) with a thin, <2 nm, MgO layer and B-alloyed electrodes reveals B diffusion into the MgO, resulting in a Mg-B-O tunnel barrier. This {approx}2 nm thick interfacial layer forms due to oxidation of CoFeB during radio frequency sputtering of MgO and subsequent B diffusion into MgO during annealing. We measure a room-temperature tunneling magnetoresistance (TMR) of {approx}200% in IrMn/CoFeB/Mg-B-O/CoFeB MTJs after annealing, demonstrating that thin Mg-B-O barriers can produce relatively high TMR.

• OSTI ID: 21294196
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 3 Vol. 95; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
BORON
BORON ALLOYS
COBALT ALLOYS
DEPOSITION
DIFFUSION
ELECTROCHEMISTRY
ELECTRODES
IRON ALLOYS
LAYERS
MAGNESIUM OXIDES
MAGNETISM
MAGNETORESISTANCE
OXIDATION
RADIOWAVE RADIATION
SPUTTERING
SUPERCONDUCTING JUNCTIONS
TEMPERATURE RANGE 0273-0400 K
THIN FILMS
TUNNEL EFFECT