Dresden 2006 – wissenschaftliches Programm
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DS: Dünne Schichten
DS 23: Nanowires, nanoparticles and nanostructures
DS 23.2: Vortrag
Donnerstag, 30. März 2006, 16:15–16:30, GER 38
Electromigration in single- and polycrystalline silver nanowires — •M. Hartmann and G. Dumpich — Experimentalphysik, Universität Duisburg-Essen (Standort Duisburg), Lotharstr. 1, 47048 Duisburg
Electromigration measurements are conducted for
polycrystalline silver nanowires prepared by electron beam
lithography (EBL) as well as for singlecrystalline nanowires grown
by self organization of Ag onto vicinal Si substrates. The
observed resistance changes as a function of time can be directly
correlated to structural changes in the nanowire, such as void and
hillock formation, by in situ observation in a scanning
electron microscope (SEM). A direct comparison between single- and
polycrystalline wires in a parallel connection shows that the
ratio between the two governing forces, the windforce and the
direct force, differs greatly for these wire types.
While
polycrystalline wires exhibit the electrical breakdown at the
cathode, the atomic mass flux in singlecrystalline wires is just
the other way around. This indicates a higher absolute value of
the direct force in singlecrystalline nanowires - as compared to
the wind force - which is found in nearly no other system.
However, by increasing the current density in these
singlecrystalline wires the direction of the diffusion is found to
change its sign at a certain critical value of jc. This
effect is discussed in terms of current induced defect formation.
This work is supported within SFB 616.