Effect of a Ti diffusion barrier on the cobalt silicide formation: solid solution, segregation and reactive diffusion

Diffusion barriers play an important role in numerous phase formation processes. A well known example microelectronics is the reactive diffusion growth of silicide thin films which are applied as contact materials. In this work, effect a Ti interlayer on kinetics CoSi by investigated. Therefore, Co(100nm)/Ti(5nm) deposited Si(111) annealed at various temperatures. Transmission electron microscopy and atom probe tomography allow to study evolution microstructure local compositions after each annealing. It observed that starts Ti/Si interface it controlled Co through interlayer. The keeps its during CoSi. At higher annealing temperatures, Si layer evidenced. First, segregates grain boundaries polycrystalline top before reacts cobalt silicides. Also CoSi/Si occurs may affect processes reaction interface. Beyond experimental observations, model developed quantify diffusivity base investigated growth. Furthermore, order estimate formed solid solution segregation layer. Both models can be generally for similar material configurations diffusivities interlayers or predict