Synthesis of Spatially Controlled Nanostructures by Ion Implantation in V-Grooves on (001) Si Surfaces

Abstract

AbstractThe synthesis of spatially controlled Ge nanowires and nanoclusters by Ge+ ion implantation in oxidized V-grooves on (001) Si surfaces has been studied experimentally as well as theoretically. The V-grooves were prepared by anisotropic wet chemical etching and thermal oxidation. The SiO2-covered V-grooves were implanted with 70 keV Ge+ ions up to a fluence of 1017 cm−2. Ge accumulates within the SiO2 at the bottom of the V-groove, which has been proven by analytical TEM (EDX-mapping). Theoretical studies have shown that the Ge accumulation is caused by the V-groove geometry, forward sputtering, and re-deposition. During subsequent annealing the redistributed Ge forms a nanowire by precipitation, ripening and coalescence. Kinetic lattice Monte Carlo simulations of the nanowire formation process show growth instabilities and self-organization phenomena.