DocumentCode :
38484
Title :
The Effects of Deposition Rate and Annealing on CoFeB/MgO/CoFeB Perpendicular Magnetic Tunnel Junctions
Author :
Ching-Ming Lee ; Lin-Xiu Ye ; Hau-Kang Chen ; Te-Ho Wu
Author_Institution :
Taiwan SPIN Res. Center, Nat. Yunlin Univ. of Sci. & Technol., Yunlin, Taiwan
Volume :
49
Issue :
7
fYear :
2013
fDate :
Jul-13
Firstpage :
4429
Lastpage :
4432
Abstract :
In this study, we report the effects of deposition rate and composition of CoFeB on the magnetic properties of CoFeB/MgO/CoFeB structures. We found that the asymmetry exists not only in different deposition stack sequences (bottom structure Ta/CoFeB/MgO and top structure MgO/CoFeB/Ta), but also in different compositions of CoFeB. Co40Fe40B20 is more suitable for the bottom structure, while Co20Fe60B20 has better perpendicular magnetic anisotropy for the top structure. Based on the results The full pMTJ stacks of structure Ta 5/Co40Fe40B 1.3/MgO 1/Co20Fe60B20 2.2/Top layer (nm unit) were fabricated with different deposition rates and annealing temperatures. We found that low deposition rate (0.03 nm/s) can prevent overlapping magnetization reversal of both free and fixed layer. The antiferromagnetic coupling between the free and fixed layer was found to increase with annealing temperature which can be identified as the consequence of orange-peel coupling.
Keywords :
annealing; antiferromagnetic materials; boron alloys; cobalt alloys; iron alloys; magnesium compounds; magnetic tunnelling; magnetisation reversal; perpendicular magnetic anisotropy; tantalum; CoFeB composition effect; CoFeB-MgO-CoFeB perpendicular magnetic tunnel junctions; CoFeB-MgO-CoFeB structures; Ta-CoFeB-MgO-CoFeB-Ta; annealing effect; annealing temperatures; antiferromagnetic coupling; deposition rate effect; deposition stack sequences; fixed layer; free layer; magnetic properties; orange-peel coupling; overlapping magnetization reversal; perpendicular magnetic anisotropy; size 1 nm; size 1.3 nm; size 2.2 nm; size 5 nm; Annealing; Coercive force; Iron; Junctions; Magnetic hysteresis; Magnetic properties; Magnetic tunneling; Magnetic tunnel junctions (MTJs); perpendicular magnetic anisotropy;
fLanguage :
English
Journal_Title :
Magnetics, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9464
Type :
jour
DOI :
10.1109/TMAG.2013.2239620
Filename :
6558951
Link To Document :
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