Ferromagnetic tunnel junctions with high MR and low resistance-area product

Author

Liu, Huarui ; Ren, Tianling ; Qu, Binjun ; Ouyang, Keqing ; Fan, Zengxu ; Liu, Litian

Author_Institution

Inst. of Microelectron., Tsinghua Univ., Beijing, China

Volume

1

fYear

2004

fDate

18-21 Oct. 2004

Firstpage

769

Abstract

Spin tunnel junctions with junction area between 50 and 10⁴ μm² were fabricated. A structure of glass/Ta 35Å/NiFe 20Å/IrMn 70Å/CoFe 30Å/Al₂O₃ 15Å/CoFe 50Å/NiFe 45Å/Ta 120Å was used in the junctions. The junctions have a max MR ratio of 26.17% and a low resistance-area product of 1.22 kΩ-μm². The effective barrier height is 1.04eV and the effective barrier thickness is 9.97 Å. The max tunneling magnetoresistance (TMR) values is obtained by an N₂ protecting anneal at 300°C for 3 hours applying an external field of 3000 Oe. The as-deposited junctions show a peak-shape tunneling effect. And the peak-shape effect is weaker by increasing the temperature and the time of anneal. The ferromagnetic tunnel junctions with high MR and low resistance-area product are suitable for the applications of magnetic random access memory (MRAM) and magnetic read head.

Keywords

alumina; aluminium compounds; cobalt alloys; ferromagnetic materials; iridium alloys; iron alloys; magnetic recording; magnetic storage; manganese alloys; nickel alloys; tantalum; tunnelling magnetoresistance; 1.04 eV; 3 hrs; 300 C; Ta-NiFe-IrMn-CoFe-AlO₃-CoFe-NiFe-Ta; ferromagnetic tunnel junctions; low resistance-area product; magnetic random access memory; magnetic read head; peak-shape tunneling effect; spin tunnel junctions; tunneling magnetoresistance; Annealing; Glass; Insulation; Magnetic field measurement; Magnetic heads; Magnetic separation; Protection; Sputtering; Temperature; Tunneling magnetoresistance;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State and Integrated Circuits Technology, 2004. Proceedings. 7th International Conference on

Print_ISBN

0-7803-8511-X

Type

conf

DOI

10.1109/ICSICT.2004.1435116

Filename

1435116