Observation of silicon self-diffusion enhanced by the strain originated from end-of-range defects using isotope multilayers

Si self-diffusion in the presence of end-of-range (EOR) defects is investigated using ^natSi/²⁸Si isotope multilayers. The isotope multilayers were amorphized by Ge ion implantation, and then annealed at 800-950°C. The behavior of Si self-interstitials is investigated through the ³⁰Si self-diffusion. The experimental ³⁰Si profiles show further enhancement of Si self-diffusion at the EOR defect region, in addition to the transient enhanced diffusion via excess Si self-interstitials by EOR defects. To explain this additional enhanced diffusion, we propose a model which takes into account enhanced diffusion by tensile strain originated from EOR defects. The calculation results based on this model have well reproduced the experimental ³⁰Si profiles.