Amorphisation and sub-100-nm exfoliation of hydrogen-ion-implanted silicon

摘要

The basic physics and the chemical role of H in amorphisation and exfoliation of H-ion-implanted silicon were investigated by Raman scattering and transmission electron microscopy. We found that a continuous, thermally stable, 50-nm-thick amorphous layer formed upon implantation of 5-keV H ions at 150 K. Such amorphisation is contrary to earlier theoretical predictions but gives support to recent molecular dy-rnnamics calculations. After high temperature annealing, H-saturated mono- and di-vacancies became dominant in the Si-H Raman spectrum. (001) platelets and microcracks apppeared in the c-Si beyond the a-Si layer, leading to the exfoliation of a 90-nm thick layer. Deuterium implantation leads to the formation of a thicker (～100 nm) amorphous layer but inhibits exfoliation.