Template-Directed Ion Beam Synthesis of Ge Nanowires Using V-Grooves


Template-Directed Ion Beam Synthesis of Ge Nanowires Using V-Grooves

Müller, T.; Heinig, K.-H.; Schmidt, B.

Guided self-organization of Ge nanowires in templates has been studied experimentally and theoretically. V-grooves formed in (001)Si by anisotropic etching with 30% KOH at 80°C. About 200 nm were grown on the (001)Si wafer surface and on the (111)Si V-groove sidewalls by oxidation at 1000°C in dry O2. The resulting SiO2-V-grooves were used as templates for the Ge nanowire fabrication. Ge+ ions have been implanted into the SiO2 at 70 keV with a fluence of 1017 cm-2. The theoretically predicted enrichment of Ge in the V-groove bottom during homogeneous ion implantation has been proven by analytic TEM (EDX). Annealing of Ge+ implanted samples in N2 leads to phase separation of Ge from the SiO2 matrix. Cross sectional TEM studies have confirmed the self-organization of a Ge nanowire in the SiO2 at the V-groove bottom, whereas only a thin layer of isolated Ge nanoclusters has been found in the V-groove side-walls. The kinetics of the wire formation during annealing was studied 3D Kinetic Lattice Monte-Carlo simulations. The comparison to experimental results reveals self-organization phenomena during phase separation, caused by nucleation, Ostwald ripening and coalescence. Moreover, the simulations were used to study the stability of very thin Ge nanowires against thermal fluctuations.

  • Lecture (Conference)
    Annual Meeting of the German Physical Society, Hamburg, March 26-30, 2001

Permalink: https://www.hzdr.de/publications/Publ-4694
Publ.-Id: 4694