Epitaxial growth of erbium silicide nanowires on silicon(001)

Submonolayer amounts of Er deposited onto Si(001) react with the substrate to form epitaxial nanowires of crystalline ErSi2. The ErSi2 nanowires are <1 nm high, a few nanometers wide, close to a micron long, and crystallographically aligned to Si < 110 > directions. The growth of uniaxial structures occurs because the different crystal structures of ErSi2 and Si have a good lattice match along one Si < 110 > crystallographic axis (- 1.3%) but a significant mismatch along the perpendicular Si < 110 > axis (+ 6.5%). An energetic model explains the formation of the ErSi2 nanowires. (C) 2001 Elsevier Science B.V. All rights reserved.