38éme Colloque de Métallurgie de l'INSTN
Les intermétalliques : des superalliages aux quasicristaux

J. Phys. IV France 06 (1996) C2-97-C2-102
DOI: 10.1051/jp4:1996213

Effect of Gold on the Nickel/Silicon Thin Film Reaction

D. Mangelinck¹, P. Gas², J.M. Gay³ and B. Pichaud<sup>1

1</sup>  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

Abstract
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