Analytical studies of nickel silicide formation through a thin Ti layer

Interfacial reaction sequences of a TiNi diffusion couple on Si were studied by cross-sectional TEM. At all stages of temperature treatment an amorphous interlayer was observed. There is a small window of annealing parameters where epitaxial growth of disconnected NiSi2 islands can be obtained. By further annealing NiSi forms. Principal component analysis (PCA) based AES depth profiling confirms these findings. High energy RBS with 15N4+ ions was successfully applied to study the interdiffusion processes taking place in the whole Ag/Ni/Ti metal multilayer system.