Les intermétalliques : des superalliages aux quasicristaux
J. Phys. IV France 06 (1996) C2-97-C2-102
Effect of Gold on the Nickel/Silicon Thin Film ReactionD. Mangelinck1, P. Gas2, J.M. Gay3 and B. Pichaud1
1 Laboratoire MATOP, associé au CNRS, Case 151, Faculté des Sciences de Saint Jérôme, 13397 Marseille cedex 20, France
2 Laboratoire de Métallurgie, associé au CNRS, Case 522, Faculté des Sciences de Saint Jérôme, 13397 Marseille cedex 20, France
3 CRMC2-CNRS, Campus de Luminy, Case 913, 13288 Marseille cedex 9, France
The solid state reaction between a nickel thin film and a silicon substrate leads to the sequential formation of Ni2Si, NiSi and NiSi2. The growth of the two first silicides occurs at low temperature (200-300°C) and is controlled by nickel diffusion. NiSi2 is only formed in a brutal manner at high temperature which indicates a nucleation controlled formation. We show that the addition of gold to the nickel film drastically affects these characteristics : Ni2Si and NiSi appear simultaneously and the nucleation temperature of NiSi2 is lowered. The solubility of gold in the three silicides is limited which induces a precipitation of gold. Depending on temperature this precipitation takes various forms : gold enriched surface layer or gold clusters at inner interfaces.
© EDP Sciences 1996