UHV chemical vapour deposition of silicon nanowires

We report on the growth of silicon nanowires by means of chemical vapour deposition in ultrahigh vacuum environment using different catalyst materials. Epitaxial growth via the vapour-liquid-solid growth mechanism of silicon nanowires is achieved with gold as catalyst on a (111)-oriented hydrogen-terminated silicon wafer. The resulting wires are mostly (111) oriented. Additionally, iron and dysprosium have been successfully tested as catalyst material for nanowire growth below the eutectic temperature. The nanowires grown with Fe or Dy exhibit a transition from epitaxial growth to polycrystalline growth with increasing height.