New plasma source with low electron temperature for fabrication of an insulating barrier in ferromagnetic tunnel junctions

Author

Nishikawa, Kazuhiro ; Tsunoda, Masakiyo ; Ogata, Satoshi ; Takahashi, Migaku

Author_Institution

Dept. of Electron. Eng., Tohoku Univ., Sendai, Japan

Volume

38

Issue

5

fYear

2002

fDate

9/1/2002 12:00:00 AM

Firstpage

2718

Lastpage

2720

Abstract

A new plasma source, characterized as low electron temperature of 1 eV and high density of 10¹² cm^-3, is introduced to the Al oxidation process in the magnetic tunnel junction (MTJ) fabrication. The MTJ fabricated with this new plasma source shows a high magnetoresistance ratio of about 50%. As a peculiar feature, the monotonous decrease of resistance area (RA) product is observed with increasing the postannealing temperature of MTJ. The decrease of the RA product is due to the decrease of the effective barrier width, which is a favorable feature to realize a low-resistance MTJ.

Keywords

MIM structures; annealing; giant magnetoresistance; magnetic multilayers; oxidation; plasma materials processing; tunnelling; barrier height; barrier width; current-voltage curves; ferromagnetic tunnel junctions; high magnetoresistance ratio; insulating barrier fabrication; ion-bombarding energy; low electron temperature plasma source; microwave-excitation plasma process; plasma oxidation process; postannealing temperature; resistance area product; tunnel magnetoresistance; Electrons; Fabrication; Insulation; Magnetic tunneling; Microwave devices; Oxidation; Plasma properties; Plasma sources; Plasma temperature; Tunneling magnetoresistance;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2002.803167

Filename

1042330