IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Thin Films Monday Sessions
       Session TF-MoP

Paper TF-MoP3
Intermixing Phenomena in Immiscible Ag/Co Bilayers and Co/Ag/Co Trilayers under KrF Laser Annealing

Monday, October 29, 2001, 5:30 pm, Room 134/135

Session: Multilayers and Thin Film Characterization Poster Session
Presenter: S. Luby, Institute of Physics SAS, Slovak Republic
Authors: S. Luby, Institute of Physics SAS, Slovak Republic
E. Majkova, Institute of Physics SAS, Slovak Republic
M. Jergel, Institute of Physics SAS, Slovak Republic
R. Senderak, Institute of Physics SAS, Slovak Republic
P. Mengucci, Uni. Ancona, Italy
G. Majni, Uni. Ancona, Italy
E. D'Anna, Uni. Lecce, Italy
G. Leggieri, Uni. Lecce, Italy
A. Luches, Uni. Lecce, Italy
M. Martino, Uni. Lecce, Italy
Correspondent: Click to Email
The discovery of GMR in multilayers of immiscible pairs of metals or alloys is the stimulus for the progress in the field of microdevices. Consequently, the study of the thermal stability of GMR structures becomes topical. In the last years a couple of papers on excimer laser induced diffusion in layered structures appeared. In one of them we have studied intermixing in Co/Ag/Co trilayers under XeCl laser thermal treatment. In this paper we have employed thermally more effective KrF laser and the processed structures were composed of layers only several nm thick. Bilayers and trilayers were e-beam deposited in UHV at room temperature onto oxidized Si substrates. The samples were processed by fluences F=0.1-0.25 Jcm@super -2@ with number of pulses @<=@1000 directed to the same irradiation spot.The samples were studied by RBS, XRD, grazing incidence XRD, X-ray reflectivity and sheet resistance measurements. The temperature and depth of melting vs. time in irradiated structures was obtained by numerical computations. Using a broad interval of heat treatments we were able to study the intermixing phenomena at various interfaces. At solid- solid interfaces the grain boundary diffusion of Ag into Co layers dominates the intermixing. The preexponential factor and activation energy of diffusion are D@sub 0@ ~ 10@super -10@ m@super2@s@super-1@ and E= 0.4 eV. At solid liquid interfaces the sharpening of previously deteriorated profiles (probably by back diffusion in immiscible systems) was observed at F=0.2 Jcm@super -2@. Here, the value E=1.5 eV was typical. The jumping of Ag clusters seems to be an explanation of the observed value. Using liquid-liquid interactions granular Ag-Co films were obtained. The phenomena in laser treatment are complex, however, they provide more degrees of freedom due to the controlled depth of melting and delivery of energy in well-defined quanta.