NiSi formation through a semipermeable membrane of amorphous Cr(Ni)

Abstract
Following heat treatments of Pt encapsulated Ni80Cr20 thin films on silicon substrates at temperatures ranging from 300 to 500 °C, it has been discovered that Cr atoms segregate at the original NiCr/Si interface to form an amorphous layer, while Ni atoms diffuse into the Si to form Ni silicide. The Cr‐rich amorphous layer acts as a ‘‘semipermeable membrane’’ which selectively passes Ni to form a very uniform NiSi layer.