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| Compositional Change of MgO Barrier and Interface in CoFeB/MgO/CoFeB Tunnel Junction after Annealing |
| Journal of Magnetics, Volume 11, Number 1, 31 Mar 2006, Pages 25-29 |
J.Y. Bae*  (Department of Materials Science and Engineering, KAIST), W.C. Lim(Department of Materials Science and Engineering, KAIST), H.J. Kim(Department of Materials Science and Engineering, KAIST), D.J. Kim(Department of Materials Science and Engineering, KAIST), K.W. Kim(Device Lab., SAIT), T.W. Kim(Device Lab., SAIT), T.D. Lee(Department of Materials Science and Engineering, KAIST) |
| Abstract |
| Recent experiments have demonstrated high TMR ratios in MTJs with the MgO barrier [1,2]. The CoFeB/MgO/CoFeB junctions showed better properties than the CoFe/MgO/CoFe junctions because the MgO layer had a good crystalline structure with (001) texture and smooth and sharp interface between CoFeB/MgO [3]. The amorphous CoFeB with 20 at%B starts the crystallization at 340℃[4] and this crystallization of the CoFeB helps obtaining the high TMR ratio. In this work, the compositional changes in the MgO barrier and at the interface of CoFeB/MgO/CoFeB after the CoFeB crystallization were studied in annealed MTJs. XPS depth profiles were utilized. TEM analyses showed that the MgO barrier had (100) texture on CoFeB in the junctions. B in the bottom CoFeB layer diffused into the MgO barrier and B-oxide was formed at the interface of CoFeB/MgO/CoFeB after the CoFeB crystallization. |
| Keywords: magnetic tunnel junction; MgO barrier; CoFeB electrode; interface analysis |
| DOI: |
| Full Text: PDF |
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