Initial growth mode of Er silicide on Si(111) by solid phase epitaxy

Abstract

Er in the 0–2 monolayer (ML) range is deposited on Si(111) at room temperature and subsequently annealed at 500°C. The silicide layers obtained in this way are studied by scanning tunneling microscopy and angle-resolved photoemission. Large scale images demonstrate a layer-by-layer growth mode up to 2 ML at 500°C. This is confirmed by monitoring the dangling bond surface state intensity at K̄ of single layer two-dimensional p(1 × 1) silicide in photoemission versus Er coverage. While only monolayer islands are formed up to ∼ 0.9 ML, double layer bulk-like silicide with (√3 × √3)R30° superstructure becomes visible above this coverage. For both single and double layer silicide surfaces atomic resolution could be achieved that indicates a remarkable degree of surface atomic order and very similar surface reconstructions in spite of the different p(1 × 1) and √3 periodicities.