Low resistance spin-dependent tunneling junctions with naturally oxidized tunneling barrier

Author

Sin, K. ; Mao, M. ; Chien, C. ; Funada, S. ; Miloslavsky, L. ; Tong, H.C. ; Gupta, S.

Author_Institution

Read-Rite Corp., Freemont, CA, USA

Volume

36

Issue

5

fYear

2000

fDate

9/1/2000 12:00:00 AM

Firstpage

2818

Lastpage

2820

Abstract

We investigated the effect of aluminum thickness on RA (resistance area product) and MR ratio in spin-dependent tunnel junctions. Very low RA values below 40 Ω μm₂ and a maximum MR ratio of 6% were obtained in Ni₈₁Fe₁₉/Al₂O₃/Ni₈₁Fe₁₉ tunneling junctions fabricated using natural oxidation of aluminum. The MR ratio significantly increased with use of Co₉₀Fe₁₀ electrodes. Using natural oxidation of 6 Å aluminum, RA and MR ratio of these junctions are ~50 Ω μm² and ~28%, respectively. The MR ratio and the junction resistance strongly depend on the aluminum thickness. The optimum thickness of aluminum is 6-7 Å fur natural oxidation

Keywords

MIM structures; Permalloy; alumina; ferromagnetic materials; giant magnetoresistance; magnetic heads; magnetic multilayers; oxidation; spin valves; tunnelling; 6 to 7 angstrom; Co₉₀Fe₁₀; MR ratio; Ni₈₁Fe₁₉-Al₂O₃-Ni ₈₁Fe₁₉; aluminum thickness effect; giant magnetoresistance; low resistance junctions; magnetic RAM; magnetic heads; naturally oxidized tunneling barrier; optimum thickness; resistance area product; spin-dependent tunneling junctions; Aluminum; Electrodes; Iron; Magnetic heads; Magnetic tunneling; Optical films; Oxidation; Silicon compounds; Sputtering; Tunneling magnetoresistance;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.908599

Filename

908599