Fachbereich 11 - Physik
Institut für Materialphysik
Nanoanalysis of Interreactions

Diffusion induced recrystallization of Au/Cu thin films

The earliest stages of interdiffusion between Au/Cu were investigated by HRTEM and Z-contrast microscopy. Although both metals crystallize in a f.c.c. structure, which let assume a simple random walk on a common host lattice, the reaction gets quite interesting because of the lattice size mismatch between both components. We could prove that the early diffusion proceeds in two stages, a first very quick semi-coherent stage is followed by a complete recrystallization of the initially epitaxial layers, into a complex nano-crystalline morphology. The first semi-coherent step was shown by quantitative arguments to cease because of a vacancy depletion inside the reaction zone. It is assumed that this behaviour is rather general in the case of considerable lattice mismatch.

Drittmittelgeber:

Deutsche Forschungsgemeinschaft (Einzelprojekt)

Beteiligte Wissenschaftler:

F. Hartung, C. Lang (Univ. Göttingen), G. Schmitz (Projektleiter)

Veröffentlichungen:

F. Hartung, G. Schmitz, Interdiffusion and reaction of metals: The influence and relaxation of mismatch induced stress, Phys. Rev. B 64, 245418, 2001

C. Lang, G. Schmitz, R. Kirchheim, Reactive interdiffusion of Cu/Co/Au thin film couples investigated by 3-dimensional atomprobe, Defect and Diffusion Forum 194-199, 1525-1531, 2001

C. Lang, G. Schmitz, Microstructure-controlled interdiffusion of Cu/Co/Au thin films investigated by 3-dimensional atomprobe, Mat. Sci. Eng. A (2003) in press