In situ x-ray diffraction study of CoSi{sub 2} formation during annealing of a Co/Ti bilayer on Si*(100)

X-ray diffraction (XRD) was performed in situ during annealing of a Co/Ti/Si(001) multilayer, which produced an epitaxial CoSi{sub 2} layer. The results indicate that the Ti layer did. not stay intact during the reaction, and thus could not act like a membrane, moderating Co/Si interdiffusion. A strongly textured metastable phase (M) formed prior to CoSi{sub 2} nucleation. This intermediary reaction product was unobservable upon completion of the anneal. We report that nucleation and growth of CoSi{sub 2} on Si(100) took place in the presence of M, a new Co-Ti-Si-(O) phase, located at the metal/Si interface. M might play an important role in the perfection of the silicide. Ti and Co metals intermix already below 300{degrees}C, and there was evidence that metallic Ti precipitated at the surface, commencing at 550{degrees}C.