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

Abstract 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 dynamics 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. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)