Magnetic tunnel junctions with barriers fabricated by means of UV-light assisted oxidation
Rottländer, P. (Corresponding author)
Publikationen vor 2000; PRE-2000; Retrocat
Jülich Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag 2000
70 p.
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Book
ohne Topic
Berichte des Forschungszentrums Jülich 3748
OpenAccess
OpenAccess
Please use the identifier: http://hdl.handle.net/2128/23914 in citations.


Ultraviolett light assisted oxidation has been applied for the first time to oxidize the barriers in ferromagnetic tunnel junctions. These consist of two ferromagnetic films separated by a thin insulating barrier layer. Samples were magnetically characterized by Magnetooptical Kerr effect rneasurements, where separate switching fields of the ferromagnetic layers were found. The measured Current-Voltage characteristics suggest electron tunnelling as the predominant transport mechanism. This shows that the new oxidation rnethod produces reliable tunnel junctions with a high yield. Area resistivities are on the order of 1 k$\Omega \mu$m$^{2}$ which is very attractive as the key device for future rnagneto random access rnemories. Magnetoresistance ratios of the tunnel elements usually ranged between 10% and 13%. Transport measurements support the theoretically supported assumption that ultraviolet light supported oxidation is self-limiting. lf the electrode resistance of tunnel elements becomes comparable to the barrier resistance, the tunnel current is no langer homogeneously distributed. To account for this effect, a geometry has been used with the current contacts at opposite edges of the tunnel junction. Some calculations and simulations were performed in order to compare this geometry with some others.