Surface reconstruction ofErSi1.7(0001) investigated by scanning tunneling microscopy

Critical adatom density in nucleation of two-dimensionalp(1×1) ErSi2on Si(111): Identification of submonolayer Er phases

“…This highly anisotropic character in planes parallel to the surface contrasts with the more isotropic one observed for the (ͱ3ϫͱ3)R30°ErSi 1.7 silicide islands formed at higher coverages ͑Ͼ1 ML͒ that adopt a hexagonal or triangular shape. 7 We suggest that the ͑2ϫ1͒ islands correspond to a form of defected ErSi 1.7 with a ͑2ϫ1͒ as opposed to (ͱ3ϫͱ3)R30°Si vacancy arrangement. Indeed, such a silicide phase is quite similar to the orthorhombic form of ErSi 1.7 observed in bulk with lattice parameters aϭ6.538 Å, bϭ3.793 Å, and cϭ4.082 Å ͑Ref.…”

“…5 The 2D ErSi 2 and 3D ErSi 1.7 films are formed typically for coverages Ϸ1 ML and Ͼ1 ML, respectively, and are terminated in a very similar fashion with a Si͑111͒ bilayer without Si vacancies. 4,6,7 Yet, up to now very little is known about the Er phases observed in the submonolayer range. Angle-resolved photoemission ͑ARP͒ and scanning tunneling microscopy ͑STM͒ revealed that the 2D ErSi 2 phase grows essentially in a layer-by-layer way in the 0.5-1 ML range when the Er is deposited at room temperature ͑RT͒ and subsequently annealed.…”

First principles total energy calculations of the surface atomic structure of yttrium disilicide on Si(111)

“…To understand our results we shall refer first to the atomic structure of the ErSi 1.7 epitaxially grown on Si(1 1 1). The interpretation of the atomic configuration was given in terms of two models, the first one was proposed by Roge et al [14,15] and the second one by Martin-Gago et al [16,17]. In the first model, a silicon atom (Si up ) of the first layer (of the surface bilayer) is on top of the vacancy, and it relaxes inward as shown schematically in Fig.…”

“…Although there is a previous theoretical work in the same system, the authors have assumed the so-called BT 4 atomic geometry and optimized it [23]. (2) The growth of a few layers of YSi 1.7 on Si(1 1 1) was studied considering models [14][15][16][17], which have been initially proposed to explain the adsorption of RE elements on Si(1 1 1), but up to now, there are no theoretical calculations for YSi 2 on Si(1 1 1). These models consist of bulk-like Si bilayers without vacancies in the topmost plane.…”

Atomic structure of thin dysprosium-silicide layers on Si(111)

“…Silicides of the trivalent rare earth metals grown as thin films on silicon surfaces are currently of high interest because of their low Schottky-barrier heights on n-type substrates [1][2][3][4][5], their epitaxial growth on Si(1 1 1) [6][7][8][9][10][11][12][13][14][15][16][17][18] and the self-organized formation of nanowires on Si(0 0 1) [19][20][21][22][23]. These silicide films can be prepared by rare-earth deposition and subsequent annealing.…”