Ion-beam-induced recrystallization in Si(100) studied with slow positron annihilation and rutherford backscattering and channeling

Ion-beam-induced crystallization in silicon preamorphized by Ge-ion implantation was studied by combined means of Rutherford backscattering and channeling, and positron annihilation. The epitaxial regrowth of amorphous surface layers in a (100) Si substrate has been studied with irradiation of 400-keV Ar⁺ ions at the temperature of 400°C. The ion-beam-induced epitaxy was found to result in a drastic increase in the positron lifetime to a maximum value of 400 psec in the recrystallized silicon layer. It is demonstrated that vacancy migration is promoted during the epitaxial recrystallization to form defect complexes like trivacancies and/or quadrivacancies.