Growth control of self-assembled ErSi2 nanowires on Si(001) and Si(110) surfaces

In this paper, we describe the fabrication of erbium disilicide (ErSi2) nanowires on clean silicon surfaces by self-assembled epitaxial growth due to a lattice mismatch between ErSi2 and silicon substrate. As surface treatment and surface orientation were important for controlling the nanowire growth, we formed a clean surface of Si(001)2 x 1 and Si(110)1 x 1. Then, ErSi2 nanowires were formed on the silicon surface by solid phase epitaxial growth. The silicon surfaces and the nanowires were observed using ultrahigh vacuum scanning tunneling microscopy (UHV-STM). The length of the nanowires on the Si(001) surface ranged from a few 10 s of nm to a few 100 s of nm, and the growth occurred in the orthogonal two-way directions of Si[110] and Si[110]. Although the length of the nanowires on Si(110) was almost the same as that on Si(00 1), the growth occurred in the one-way direction of Si[110]. This result indicates that the growth direction of the self-assembled nanowires can be controlled by the Si surface orientation. (c) 2007 Elsevier B.V. All rights reserved.