Simultaneous Formation of AlB₂-Type and ThSi₂-Type Nanoislands of Er Silicide by Using a Prepatterned Si(001) Substrate

We report the simultaneous growth of hexagonal AlB₂-phase and tetragonal ThSi₂-phase nanoislands of erbium silicide on the same silicon substrate. As a new technique, the patterned Si(001) surface with pits in a reverse-pyramid shape and 111 sidewalls is taken as the substrate template. The distribution of nanoislands reveals that the upward diffusion over surface steps plays an influential role on the location of islands. Si 111 facets on the pit sidewalls actually provide growth symmetry for the hexagonal islands. This work paves the way for exploring the intrinsic electrical transport properties of metal-semiconductor nanocontacts.