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Highly Charged Ion Modified Magnetic Tunnel Junctions

Published online by Cambridge University Press:  01 February 2011

Holger Grube ,
J. M. Pomeroy ,
A. C. Perrella  and
J. D. Gillaspy
Holger Grube
Affiliation:
hgrube@nist.gov, National Institute of Standards and Technology, Atomic Physics, 100 Bureau Drive, Mail Stop 8423, Gaithersburg, MD, 20899, United States, 301 975-4609
J. M. Pomeroy
Affiliation:
jpomeroy@nist.gov, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 8423, Gaithersburg, MD, 20899, United States
A. C. Perrella
Affiliation:
acperrella@yahoo.com, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 8423, Gaithersburg, MD, 20899, United States
J. D. Gillaspy
Affiliation:
john.gillaspy@nist.gov, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 8423, Gaithersburg, MD, 20899, United States
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Abstract

We have used highly charged ions (HCIs) such as Xe44+ to modify ultrathin aluminum oxide barriers in magnetic tunnel junctions (MTJs) in order to controllably adjust their electrical properties independently of oxide thickness. We have reduced the resistance area (RA) product of our MTJ devices by up to three orders of magnitude down to our present measurement uncertainty limit of 30 Ω·μm2 by varying the HCI dose. Preliminary experiments indicate that HCI modified Co/Al2O3/Co MTJs have a reduced magnetoresistance (MR) of ≈ 1% at room temperature as compared to ≈ 10% for undosed devices. The goal of this effort is to fabricate a magnetic field sensor in current-perpendicular-to-plane (CPP) geometry with an RA optimized for hard drive read heads. This is an improvement over presently demonstrated CPP architectures based on giant magnetoresistance or tunnel junctions, whose RAs are either to low or too high.

Keywords

magnetoresistance (transport)thin filmion-solid interactions
Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 960: Symposium N – Self Assembly of Nanostructures Aided by Ion- or Photon-Beam Irradiation—Fundamentals and Applications , 2006 , 0960-N08-02
Copyright
Copyright © Materials Research Society 2007

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References

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