Evolution of early formed NiSi2 during the reaction between Ni(W, Pt) films and Si (001)

Abstract

The early formation of NiSi2 has been observed during the solid state reaction between Ni(W,Pt) films and Si (001) substrates at a temperature of 295 °C. The maximum contents of W and Pt additions are ~28 at.%. In-situ X-ray diffraction (XRD) measurements and rapid thermal processing (RTP) were performed at different temperatures and the annealed samples were subsequently characterized by atom probe tomography (APT). Distinct structures containing different silicides were observed and it enables us to put forward a mechanism showing the evolution of early formed NiSi2. Ni diffusion slows down resulting from the effect of alloying elements and the redistribution of Pt and W strongly influences the formation sequence of Ni silicides. Keywords: NiSi2, Ni silicides, Alloying elements, Phase sequence, W and Pt