Simultaneous Formation of AlB 2 -Type and ThSi 2 -Type Nanoislands of Er Silicide by Using a Prepatterned Si(001) Substrate

We report the simultaneous growth of hexagonal AlB 2-phase and tetragonal ThSi 2-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.