Composition measurement of the Ni-silicide transient phase by atom probe tomography

Abstract

The transient phase observed during the reaction of a Ni(Pt) alloy with a (001)Si substrate is studied using in situ x-ray diffraction and atom probe tomography microscopy. This transient phase exhibits a diffraction peak at 47°, and is found to have a uniform composition corresponding to Ni0.6Si0.4. During the reaction, it is located between a δ-Ni2Si layer and a thin (nanocrystalline or amorphous) NiSi layer in contact with Si. The Pt atoms are found in the δ-Ni2Si grain boundaries, while they have not been detected in the NiSi layer.