Structure of crystallized layers by laser annealing of 〈100〉 and 〈111〉 self-implanted silicon samples

Abstract

Channeling effect techniques with a 2.0 MeV He⁺ Rutherford backscattering and transmission electron microscopy were used to characterize the crystallized layers after Q-switched ruby laser irradiation of 4000 Å thick amorphous layer on 〈100〉 and 〈111〉 underlined crystal substrates. At a laser energy density of 2.5 J/cm² the crystal layer on the 〈111〉 specimen contains a large density of stacking-faults, that on 〈100〉 specimen contains a very small amount of screw dislocation lines. High quality single-crystal layers have been obtained after irradiation at 3.5 J/cm². From a comparison with the growth rate and defect structure observed in thermally annealed implanted-amorphous layers, we propose that crystal growth by 50 ns pulse laser annealing occurs by melting the amorphous layer.