Growth of zirconium silicide nanostructures on vicinal and flat Si(111)-7 × 7 surfaces

Abstract

Using in situ scanning tunneling microscopy and low-energy electron diffraction, we performed investigations on the growth of zirconium silicide on vicinal and flat Si(111)-7 × 7 surfaces. In the case of a solid-phase reaction, submonolayer zirconium deposition onto vicinal Si followed by successive annealing results in the formation of zirconium silicide nanostructures, which are distributed randomly on the surface. These nanostructures evolved into rod-shaped islands with axes running along the substrate directions at the late stage of the coarsening process. When 2-3 monolayers of Zr are deposited on Si at 520 °C, an extended network with rod-like silicide domains was developed, which is controlled by the elastic strain-relief mechanism. The atomic structures of these silicide features were identified and they are considered to adopt C49 ZrSi2. The reaction and growth on a flat surface with less Zr coverage at higher temperatures led to the formation of longer and narrower nanowires. The relations between the variety of nanostructures and the different growth conditions are addressed. © IOP Publishing Ltd.