Hamburg 2001 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

AM: Magnetismus

AM 9: Poster: Magnetowid. (1-17), Dü. Schichten (18-34), Oberfl
ächenmag. (35,36), Mikr. Methoden (37-45), Mikromag. (46-58), Phasenüberg. (59-77), Spektroskop. (78-91), Nanokr.Mat.(92-96), Anisotrop. (97-101), Schmelzen(102-104),Sonst/postdeadl.(105-109)

AM 9.11: Poster

Dienstag, 27. März 2001, 14:45–19:00, Foyer S 3

Dielectric breakdown in magnetic tunnel junctions with Al₂O₃ barrier — •J. Schmalhorst¹, H. Brückl¹, G. Reiss¹, M. Vieth², G. Gieres² und J. Wecker² — ¹Universität Bielefeld — ²Siemens AG, Zentralabteilung Technik, Erlangen

The temperature and dielectric stability of magnetic tunnel junctions are investigated. The magnetically hard electrode of the junctions is an artificial antiferromagnet (e.g. Co/Cu/Co in the first coupling maximum), the soft electrode is a Co/Fe bilayer or a single Ni₈₁Fe₁₉ layer. The two ferromagnetic electrodes are separated by a thin plasmaoxidized Al layer. Here we present data of the evolution of the barrier properties (height, thickness, asymmetry) and the dielectric stability of the junctions as a function of the annealing temperature. The samples are isochronally annealed up to 500^oC for 1h in a high vacuum furnace with a base pressure below 5x10⁻⁵ mbar. It is shown, that the barrier is thermal and dielectric stable up to 500^oC. The changes of the barrier properties are related to diffusion processes in the layer system, which are found by Auger depth profiling and X-ray diffraction.

The authors gratefully acknowledge support of this project by the German Ministry for Education and Research, BMBF, under Grant No. 13N7380/4.