Precipitation-enhanced diffusion of nickel in dislocation-free silicon studied by in-diffusion and annealing processes

Abstract

To examine the site-exchange mechanism of nickel atoms in dislocation-free silicon, the effect of nickel precipitates on the in-diffusion and annealing rates has been investigated. The variation of the concentration of substitutional nickel atoms with time in these processes follow well the theoretical prediction for the dissociative mechanism. It is suggested that nickel atoms in dislocation-free silicon exchange their sites via the dissociative mechanism, or the dominant point defects mediating the site exchange are vacancies. In-diffusion and annealing processes of nickel atoms are accelerated by the presence of the nickel precipitation, indicating that nickel precipitates, or precipitation-induced lattice defects play a role of sinks and sources of vacancies in the bulk.