Formation of Amorphous Interlayers by Solid-State Diffusion in Refractory Metal/Silicon Systems

Formation and growth of amorphous interlayers (a-interlayers) in nine refractroy metal and silicon systems by solid-state diffusion have been investigated by conventional and high resolution transmission electron microscopy. The amorphous interlayers were found to form in samples annealed at 350–650 °C. The growth was found to follow a linear growth law initially then slow down until a critical thicknees was reached. The interface structures were examined. The correlations among difference in atomic size between metal and Si atoms, growth rate and activation energy of the linear growth, critical and maximum a-interlayer thickness, the largest heat of formation energy for crystalline silicides, the calculated free energy difference in forming amorphous phase as well as atomic mobility in refractroy metal/silicon systems are discussed.