Characterization of epitaxially grown indium islands on Si(111)

Indium deposition onto on-axis Si(111) substrates and those miscut by 2.5°toward [11 2 ] was investigated. The Si substrates were held at temperatures ranging from room temperature up to 475°C and the In deposition rate was varied by a factor of ∼20. All depositions were performed under ultrahigh vacuum conditions onto surfaces that were cleaned in situ. For growth at 100°C and room temperature, the In films organize into three-dimensional islands. This result suggests that In deposition onto on-axis or miscut Si(111) substrates at temperatures lower than the In melting point of 157°C is a viable route to form In seeds for epitaxial Si or Ge nanowire growth using the vapor-liquid-solid method. The morphology of the resultant island ensembles and their formation mechanisms are discussed.