UA-Georgia Tech Partner to Fabricate a prototype confined current path, current perpendicular to the plane magnetoresistive device for materials science studies

C. Papusoi, Z. Tadisina, A. Highsmith, J. Weston, S. Gupta, P. LeClair, H. Fujiwara, and G.J. Mankey, University of Alabama; Paul Joseph, Georgia Institute of Technology.

As written bits get smaller on magnetic hard drives, a different type of sensor must be used to read the narrow tracks of information. The sensing current must be applied perpendicular to the sensor layers in order to enable electrical contacts to be made at the top an bottom, rather than the sides. Tracks of written bits on technology demos now have a width of less than 100 nm, so our prototype devices must be at least this small.

Our program has focused on materials development for these sensors; with recent reports on measurements on sheet films using neutron scattering techniques at national labs [see for example 1]. To test the performance of these materials in nanoscale devices, we traveled to Georgia Tech-NNIN to fabricate nanoscale contacts in giant magnetoresistive devices. The figure shows an optical microscope image of the 0.1 millimeter square electrical contacts, and electron microscope images of the 6-micrometer diameter insulating pad and the tiny 75-nanometer contact area of the prototype device which will be used for design of materials which exhibit desirable sensor response characteristics.

1. Magnetic properties of uniaxial synthetic antiferromagnets for spin-valve applications, Z. Zhao, P. Mani, G.J. Mankey, G. Gubbiotti, F. Spizzo, S. Tacchi, W.-T. Lee, C.T. Yu and M.J. Pechan, Phys. Rev. B 71, 104417 (2005).