Triple-junction contribution to diffusion in nanocrystalline Si

摘要

The influence of triple-junctions on experimental Ge diffusion profiles (850-1000 ℃) in nanocrystalline Si is investigated using three-dimensional finite element simulations. We found that triple-junction diffusion is not negligible in nanocrystalline Si made of 40 nm wide grains. Ge triple-junction diffusion coefficient follows the Arrhenius law 5.72 × 10~4 exp(-3.24 eV/kT)cm~2 s~(-1). It is approximately 4.7 × 10~2 times higher than grain boundary diffusion coefficient, even though diffusion in triple-junction and in grain boundary exhibits similar activation energy.