Thermal Stability and Growth Behavior of Erbium Silicide Nanowires Self-Assembled on a Vicinal Si(001) Surface

Erbium silicide nanowires are self-assembled on vicinal Si(001) substrates after electron beam evaporation and post annealing at 630°C In−situ scanning tunneling microscopy investigations manifest that the nanowires will successively shrink and transform into a nanoisland with annealing prolonged. Meanwhile, a structural transition from hexagonal AlB₂ phase to tetragonal ThSi₂ phase is revealed with high-resolution transmission electron microscopy. It is also found that the nanowires gradually expand to embed into the substrates during the growth process, which has much influence on the shape instability of nanowires. Additionally, a multiple deposition-annealing treatment is given as a novel growth method to strengthen the controlled fabrication of nanowires.