Structure of crystallized layers by laser annealing of (100) and (111) self-implanted silicon samples

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 4,000 Angstroem 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. (orig.)