Tb silicide nanowire growth on planar and vicinal Si(001) surfaces

摘要

Scanning tunneling microscopy and low energy electron diffraction were used to investigate the growth of Tb silicide nanowires on Si(001) and its dependence on Tb coverage, annealing temperature, and the vicinality of the substrate. The nanowires are observed both isolated and in bundles, and while being narrower than 4 nm, they reach lengths exceeding 500 nm. Their appearance fits a hexagonal TbSi2 structure model with Si dimer rows on top of the nanowires. The growth of exclusive parallel nanowires was achieved on vicinal surfaces. On planar samples, the nanowire growth is accompanied by the formation of a 2x7 reconstruction that shows a wetting layer like behavior. In contrast, mainly building blocks of this 2x7 reconstruction are observed on vicinal samples. (C) 2015 Elsevier B.V. All rights reserved.