학술논문

Characterization of an AlO$_{\rm x}$ Tunneling Barrier in a Magnetic Tunnel Junction by a Surface Plasmon Resonance Spectroscopy Technique
Document Type
Periodical
Source
IEEE Transactions on Magnetics IEEE Trans. Magn. Magnetics, IEEE Transactions on. 45(1):60-63 Jan, 2009
Subject
Fields, Waves and Electromagnetics
Tunneling magnetoresistance
Dielectric measurements
Magnetic tunneling
Plasmons
Magnetic resonance imaging
Electrochemical impedance spectroscopy
Magnetic analysis
Temperature dependence
Insulation
Electrical resistance measurement
Magnetic random access memory
magnetoresistance
temperature measurement
tunneling
Language
ISSN
0018-9464
1941-0069
Abstract
We measured tunneling magnetoresistance (TMR) in a magnetic tunnel junction as a function of temperature. We used surface plasmon resonance spectroscopy (SPRS)—one of the most useful tools in the analysis of dielectric function in a thin tunneling barrier—to study the correlation of AlO$_{\rm x}$ barrier quality with the temperature dependent behavior of the TMR ratio. The experimental SPRS analysis suggests that the decrease of the TMR ratio starting at 150 K is caused by residual Al metallic defects distributed within the insulating AlO$_{\rm x}$ barrier. We checked this result by measuring the junction resistances in parallel and antiparallel states.