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 Si-nat/Si-28 isotope multilayers. The isotope multilayers were amorphized by Ge ion implantation, and then annealed at 800-950 degrees C. The behavior of Si self-interstitials is investigated through the Si-30 self-diffusion. The experimental Si-30 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 30 Si profiles. (C) 2015 AIP Publishing LLC.