Mechanism about improvement of NiSi thermal stability for Ni/Pt/Si(1 1 1) bi-layered system

A thin interlayer of Pt can greatly enhance the thermal stability of NiSi films formed by rapid thermal annealing (RTA) on Si(1 1 1) substrates, as was revealed by X-ray diffraction (XRD) data and sheet resistance measurement. One possible reason for the enhanced NiSi thermal stability is attributed to the formation of the Ni0.945Pt0.055Si solid solution and its preferred orientation, leading to the decrease in the driving force and the increase in the interfacial energy change, respectively. Both of them increase the activation energy for the NiSi2 nucleation, improving the NiSi thermal stability.