An investigation was made of amorphization mechanisms, in 5MeV Si+ ion-implanted samples, by using cross-sectional transmission electron microscopic measurements. Micro-diffraction patterns and high-resolution cross-sectional transmission electron microscopic images of the amorphous/crystalline interface region indicated that the amorphous/crystalline interface was very sharp and that the amorphous transition occurred within a few atomic layers. Image simulations that were based upon the di-vacancy and di-interstitial pair model suggested that an accumulation of the di-interstitial pairs gave rise to homogeneous amorphization in ion-implanted Si.

T.Motooka, S.Harada, M.Ishimaru: Physical Review Letters, 1997, 78[15], 2980-2